Draft Regulatory Impact Analysis 

Proposed Rulemaking to Establish LightDuty Vehicle Greenhouse Gas Emission 

Standards and Corporate Average Fuel 

Economy Standards
EPA-420-D-09-003 

September 2009

Assessment and Standards Division 

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency

Draft Regulatory Impact Analysis 

Proposed Rulemaking to Establish LightDuty Vehicle Greenhouse Gas Emission 

Standards and Corporate Average Fuel 

Economy Standards
Draft Regulatory Impact Analysis 

i 

Table of Contents 

TABLE OF CONTENTS...............................................................................i

LIST OF ACRONYMS................................................................................vi

EXECUTIVE SUMMARY............................................................................ix

Greenhouse Emission Impacts of EPA’s Proposal................................................................x

Criteria Pollutant Impacts of EPA’s Proposal .....................................................................xi

Costs and Benefits of EPA’s Proposal .................................................................................xiii

CHAPTER 1: TECHNOLOGY PACKAGES, COST AND EFFECTIVENESS1-1

1.1 Overview of Technology..............................................................................................1-1

1.2 Technology Cost and Effectiveness ............................................................................1-4

1.3 Package Cost and Effectiveness................................................................................1-10

1.3.1 Explanation of Technology Packages ............................................................1-10

1.3.2 Technology Package Costs & Effectiveness ..................................................1-12

1.4 EPA’s Lumped Parameter Approach for Determining Effectiveness Synergies.1-26

1.4.1 Ricardo’s Vehicle Simulation .........................................................................1-28

1.4.2 Description of Ricardo’s Report ....................................................................1-29

1.4.3 Determination of representative vehicle classes ...........................................1-30

1.4.4 Description of Baseline Vehicle Models.........................................................1-31

1.4.5 Technologies Considered by EPA and Ricardo in the Vehicle Simulation1-32

1.4.6 Choice of Technology Packages .....................................................................1-34

1.4.7 Simulation Results...........................................................................................1-35

1.5 Comparison of Lumped-Parameter Results to Modeling Results.........................1-36

1.6 Using the Lumped-Parameter Technique to Determine Synergies in a Technology 

Application Flowpath (Identifying “Technology Pairs” to account for synergies) .......1-38

CHAPTER 2: AIR CONDITIONING................................................................ 2-2

2.1 Overview of Air Conditioning Impacts and Technologies .......................................2-2

2.2 Air Conditioner Leakage.............................................................................................2-4

2.2.1 Impacts of Refrigerant Leakage on Greenhouse Gas Emissions ..................2-4

2.2.2 A/C Leakage Credit...........................................................................................2-5

2.2.3 Technologies That Reduce Refrigerant Leakage and their Effectiveness..2-11

2.2.4 Technical Feasibility of Leakage-Reducing Technologies ...........................2-14

2.2.5 Deterioration of Leakage Controls in A/C Systems .....................................2-14

2.2.6 Other Benefits of improving A/C Leakage Performance ............................2-18
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2.3 CO2 Emissions due to Air Conditioners...................................................................2-19

2.3.1 Impact of Air Conditioning Use on Fuel Consumption and CO2 Emissions.2-

19

2.3.2 Technologies That Improve Efficiency of Air Conditioning and Their 

Effectiveness ....................................................................................................................2-28

2.3.3 Technical Feasibility of Efficiency-Improving Technologies ......................2-32

2.3.4 A/C Efficiency Credits ....................................................................................2-32

2.4 Costs of A/C reducing technologies..........................................................................2-37

2.5 Air Conditioning Credit Summary ..........................................................................2-39

CHAPTER 3: TECHNICAL BASIS OF THE STANDARDS......................... 3-1

3.1 Technical Basis of the Standards................................................................................3-1

3.1.1 Summary ............................................................................................................3-1

3.1.2 Overview of Equivalency Calculation. ............................................................3-2

3.2 Analysis of Footprint Approach for Establishing Individual Company Standards 3-

7

3.2.1 “Footprint” as a vehicle attribute ....................................................................3-8

3.2.2 Alternative Attributes .....................................................................................3-14

3.2.3 EPA Selection of the Footprint Attribute......................................................3-20

3.3 Supplemental Analysis of Relative Car and Truck Standards..............................3-23

CHAPTER 4: RESULTS OF PROPOSED AND ALTERNATIVE STANDARDS 4-1

4.1 Introduction..................................................................................................................4-1

4.2 Model Inputs.................................................................................................................4-1

4.2.1 Representation of the CO2 Control Technology Already Applied to 2008 MY 

Vehicles 4-2

4.2.2 Technology Package Approach........................................................................4-8

4.3 Modeling Process .......................................................................................................4-10

4.4 Modeling of CAA Compliance Flexibilities .............................................................4-13

4.5 Per Vehicle Costs 2012-2016 .....................................................................................4-16

4.6 Technology Penetration.............................................................................................4-19

4.7 Manufacturer-Specific Standards ...............................................................................24

4.8 Alternative Program Stringencies...............................................................................25

4.9 Assessment of Manufacturer Differences ................................................................4-33

CHAPTER 5: EMISSIONS IMPACTS ............................................................. 5-1

5.1 Overview .......................................................................................................................5-1
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5.2 Introduction..................................................................................................................5-3

5.2.1 Scope of Analysis ...............................................................................................5-3

5.2.2 Downstream Contributions ..............................................................................5-4

5.2.3 Upstream Contributions ...................................................................................5-4

5.2.4 Global Warming Potentials ..............................................................................5-5

5.3 Program Analysis and Modeling Methods ................................................................5-5

5.3.1 Models Used .......................................................................................................5-5

5.3.2 Description of Scenarios....................................................................................5-6

5.3.3 Calculation of Downstream Emissions ..........................................................5-14

5.3.4 Calculation of Upstream Emissions...............................................................5-24

5.4 Greenhouse Gas Emission Inventory.......................................................................5-24

5.5 Non-Greenhouse Gas Emission Inventory...............................................................5-26

5.5.1 Downstream Impacts of Program..................................................................5-28

5.5.2 Upstream Impacts of Program.......................................................................5-29

5.5.3 Total Program Impact ....................................................................................5-30

5.6 Model Year Lifetime Analyses..................................................................................5-31

5.6.1 Methodology.....................................................................................................5-31

5.6.2 Results...............................................................................................................5-33

5.7 Alternative 4% and 6% Scenarios ...........................................................................5-34

5.7.1 4% Scenario .....................................................................................................5-35

5.7.2 6% Scenario .....................................................................................................5-37

5.A Appendix to Chapter 5: Details of the TLAAS Impacts Analysis........................5-40

5.A.1 Introduction and Summary............................................................................5-40

5.A.2 Factors Determining the Impact of the TLAAS ...........................................5-40

5.A.3 Bounding Analysis of TLAAS Impact ...........................................................5-41

5.A.4 Approach used for Estimating TLAAS Impact............................................5-42

CHAPTER 6: VEHICLE PROGRAM COSTS INCLUDING FUEL CONSUMPTION 

IMPACTS 6-1

6.1 Vehicle Program Costs ................................................................................................6-1

6.1.1 Vehicle Compliance Costs on a Per-Vehicle Basis..........................................6-1

6.1.2 Vehicle Compliance Costs on a Per-Year Basis..............................................6-7

6.2 Cost per Ton of Emissions Reduced.........................................................................6-11

6.3 Fuel Consumption Impacts .......................................................................................6-12
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6.4 Vehicle Program Cost Summary..............................................................................6-15

CHAPTER 7: ENVIRONMENTAL AND HEALTH IMPACTS . ..............7-1

7.1 Health and Environmental Effects of Non-GHG Pollutants....................................7-1

7.1.1 Health Effects Associated with Exposure to Pollutants .................................7-1

7.1.2 Environmental Effects Associated with Exposure to Pollutants.................7-13

7.2 Non-GHG Air Quality Impacts ................................................................................7-26

7.2.1 Introduction .....................................................................................................7-26

7.2.2 Current Levels of Pollutants...........................................................................7-26

7.2.3 Impacts on Future Air Quality.......................................................................7-28

7.3 Quantified and Monetized Co-Pollutant Health and Environmental Impacts ....7-31

7.3.1 Economic Value of Reductions in Criteria Pollutants .................................7-32

7.3.2 Human Health and Environmental Benefits for the Final Rule .................7-37

7.4 Changes in Global Mean Temperature and Sea-Level Rise Associated with the 

Proposal’s GHG Emissions Reductions.............................................................................7-43

7.4.1 Introduction .....................................................................................................7-43

7.4.2 Estimated Projected Reductions in Global Mean Surface Temperature and 

Sea-Level Rise .................................................................................................................7-43

7.5 SCC and GHG Benefits.............................................................................................7-46

7.6 Weight Reduction and Vehicle Safety......................................................................7-56

CHAPTER 8: OTHER ECONOMIC AND SOCIAL IMPACTS ................... 8-1

8.1 Vehicle Sales Impacts ..................................................................................................8-1

8.1.1 How Vehicle Sales Impacts were Estimated for this Rule .............................8-1

8.1.2 Consumer Vehicle Choice Modeling................................................................8-4

8.1.3 Consumer Payback Period and Lifetime Savings on New Vehicle Purchases

8-11

8.2 ..........................................................................................................................................8-14

8.3 Energy Security Impacts ...........................................................................................8-14

8.4 Other Externalities.....................................................................................................8-16

8.4.1 Reduced Refueling Time.................................................................................8-16

8.4.2 Value of Additional Driving ...........................................................................8-17

8.4.3 Noise, Congestion, and Accidents...................................................................8-17

8.4.4 Summary of Other Externalities....................................................................8-18

8.5 Summary of Costs and Benefits................................................................................8-20
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CHAPTER 9: SMALL BUSINESS FLEXIBILITY ANALYSIS .................... 9-1
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List of Acronyms 

2-mode: 2-mode hybrid electric vehicle 

2V: 2-valves per cylinder 

4V: 4-valves per cylinder 

12V: 12 Volts 

42V: 42 Volts 

A/C: Air conditioner/conditioning 

AERO: Improved aerodynamics 

ASL: Aggressive Shift Logic 

AT: Automatic transmission 

CAFE: Corporate Average Fuel Economy 

CCP: Couple Cam Phasing 

CO2: carbon dioxide 

CVA: Camless Valve Actuation (full) 

CVT: Continuously Variable Transmission 

CVVL: Continuous Variable Valve Lift 

Deac: Cylinder Deactivation 

DICE: Dynamic Integrated Model of Climate and the Economy 

DCP: Dual (independent) Cam Phasing 

DCT: 6-speed Dual Clutch Transmission 

DOHC: Dual Overhead Camshafts 

DOT: Department of Transportation 

DVVL: Discrete (two-step) Variable Valve Lift 

EFR: Engine Friction Reduction 

EIS: Environmental Impact Statement 

EPS: Electric Power Steering 

FUND:Climate Framework for Uncertainty, Negotiation, and Distribution 

GDI: Gasoline Direct Injection 

GHG: Greenhouse gas 

HCCI: Homogenous Charge Compression Ignition (gasoline) 

HEV: Hybrid Electric Vehicle 

I3: In-line 3-cylinder engine 

I4: In-line 4-cylinder engine 

IACC: Improved Accessories 

IAM: Integrated Assessment Model 

IMA: Integrated Motor Assist 

IPCC: Intergovernmental Panel on Climate Change 

L4: Lock-up 4-speed automatic transmission 

L5: Lock-up 5-speed automatic transmission 

L6: Lock-up 6-speed automatic transmission 

LDB: Low drag brakes 

LRR: Low Rolling Resistance 

LUB: Low-friction engine lubricants 

MPV: Multi-Purpose Vehicle 

MY: Model Year 
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NESCCAF: Northeast States Center for a Clean Air Future 

NHTSA: National Highway Transportation Safety Administration 

OECD:Organization for Economic Cooperation and Development 

OHV: Overhead Valve (pushrod) 

OMB: Office of Management and Budget 

ORNL: Oak Ridge National Laboratory

PAGE: Policy Analysis for the Greenhouse Effect 

PHEV: Plug-in Hybrid Electric Vehicle 

PRTP: Pure Rate of Time Preference 

S&P: Standard and Poor’s 

SCC: Social Cost of Carbon 

SCR: Selective Catalytic Reduction 

SOHC: Single Overhead Camshaft 

SRES: Special Report on Emissions Scenarios 

S-S: Stop-start hybrid system 

THC: Thermohaline circulation 

TORQ: Early torque converter lockup 

Turbo: Turbocharger/Turbocharging 

V6: 6-cylinder engine in a “V” configuration 

V8: 8-cylinder engine in a “V” configuration 

WGII: Working group II 
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This Page Intentionally Left Blank 
Draft Regulatory Impact Analysis 

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Executive Summary 

The Environmental Protection Agency (EPA) and the National Highway Traffic 

Safety Administration (NHTSA) are issuing a joint proposal to establish new standards for 

light-duty highway vehicles that will reduce greenhouse gas emissions and improve fuel 

economy. The joint proposed rulemaking is consistent with the National Fuel Efficiency 

Policy announced by President Obama on May 19, 2009, responding to the country’s critical 

need to address global climate change and to reduce oil consumption. EPA is proposing 

greenhouse gas emissions standards under the Clean Air Act, and NHTSA is proposing 

Corporate Average Fuel Economy standards under the Energy Policy and Conservation Act, 

as amended. These standards apply to passenger cars, light-duty trucks, and medium-duty 

passenger vehicles, covering model years 2012 through 2016. They would require these 

vehicles to meet an estimated combined average emissions level of 250 grams of CO2 per 

mile in MY 2016 under EPA’s GHG program, and 34.1 mpg in MY 2016 under NHTSA’s 

CAFE program and represent a harmonized and consistent national program (National 

Program). These standards are designed such that compliance can be achieved with a single 

national vehicle fleet whose emissions and fuel economy performance improves year over 

year. The proposed National Program would result in approximately 950 million metric tons 

of CO2 emission reductions and approximately 1.8 billion barrels of oil savings over the 

lifetime of vehicles sold in model years 2012 through 2016. 

The vehicle categories covered by the rulemaking are responsible for almost 60 

percent of all U.S. transportation-related greenhouse gas emissions and include cars, sport 

utility vehicles, minivans, and pickup trucks used for personal transportation. Transportation 

related emissions are responsible for approximately 30 percent of total U.S. greenhouse gas 

emissions. Under the National Program, automobile manufacturers would be able to build a 

single light-duty national fleet that satisfies all requirements under both programs while 

ensuring that consumers still have a full range of vehicle choices. 

This draft regulatory impact analysis (DRIA) contains supporting documentation to 

the EPA proposal. NHTSA has prepared their own Proposed RIA (PRIA) in support of their 

proposal (this can be found in NHTSA’s docket for their proposal, NHTSA-2009-0059). 

While the two proposals are similar, there are also differences in the analyses that require 

separate discussion. This is largely because EPA and NHTSA act under different statutes. 

EPA’s authority comes under the Clean Air Act, and NHTSA’s authority comes under EPCA, 

and each statute has somewhat different requirements and flexibilities. As a result, each 

agency has followed a unique approach where warranted by these differences. Where each 

agency has followed the same approach—e.g., development of technology costs and 

effectiveness—the supporting documentation is contained in the draft joint technical support 

document (draft joint TSD, which can be found in EPA’s docket EPA-HQ-OAR-2009-0472). 

Therefore, this DRIA should be viewed as a companion document to the draft joint TSD and 

the two documents together provide the details of EPA’s technical analysis in support of its 

proposal. 
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Specifically, this document contains, in Chapter 1, a description of EPA’s use of 

technology packages in the OMEGA model. This discussion builds on the discussion 

contained in Chapter 3 of the draft joint TSD which provides details of technology costs and 

effectiveness but only an overview of how technologies are put together into packages for the 

OMEGA model. Chapter 1 also contains a discussion of the lumped parameter model which 

is a major part of our determination of the effectiveness of these packages. 

In Chapter 2, we present a detailed discussion of our AC credit program and the 

technology costs and effectiveness associated with new AC systems. This discussion is 

unique to this DRIA as the AC-related proposal is unique to EPA. 

In Chapter 3, we present the technical basis of EPA’s proposed standards and an 

analysis of the “footprint” approach EPA is proposing for establishing standards. In Chapter 

4, we present an overview of the OMEGA model and the modeling results (actual OMEGA 

model inputs and outputs) in support of the proposed program and the alternative standards 

that were considered. Chapter 5 presents the emission reductions expected from the proposal. 

Chapter 6 presents the program costs and fuel savings associated with EPA’s proposal. 

Chapter 7 presents the environmental and health impacts, including EPA’s discussion of the 

social cost of carbon, and Chapter 8 presents other economic and social impacts—e.g., less 

time spent refueling due to higher fuel efficiency—of the proposal. Chapter 9 presents our 

analysis of the small business impacts due to EPA’s proposal. All of these discussions—

Chapters 3 through 9—are unique to this DRIA since, even though many of the metrics are 

common between EPA and DOT, we have different results due to our use of different models 

(EPA’s OMEGA model versus DOT’s CAFE Compliance and Effects Modeling System 

(often referred to as "the CAFE model" or "the Volpe model")) and the differences in our 

programs (e.g., AC credits versus no AC credits, plus many other program flexibilities). 

Greenhouse Emission Impacts of EPA’s Proposal 

Table 1 shows reductions estimated from EPA’s proposed GHG standards assuming a 

pre-control case of 2011 MY CAFE standards continuing indefinitely beyond 2011, and a 

post-control case in which 2016 MY standards continue indefinitely beyond 2016. These 

reductions are broken down by upstream and downstream components, including air 

conditioning improvements, and also account for the offset from a 10 percent “rebound” 

effect in vehicle miles travelled as discussed in Chapter 4 of the joint draft TSD.A Including 

the reductions from upstream emissions, total reductions are estimated to reach 325 

MMTCO2eq (million metric tons of CO2 equivalent emissions) annually by 2030 (a 21 

percent reduction in U.S. car and light truck emissions), and grow to over 500 MMTCO2eq in 

2050 as cleaner vehicles continue to come into the fleet (a 23 percent reduction in U.S. car 

and light truck emissions). 

 

A “Rebound VMT” is the term used to describe the increase in driving that might occur as vehicle fuel 

consumption decreases (i.e., the fuel economy improves) since the cost per mile of operating the vehicle 

decreases. As a result of this rebound effect, the benefits of the proposed rule are offset slightly since owners of 

compliant vehicles drive more miles resulting in slightly more GHG emissions. Importantly, the adverse effects, 

or disbenefits, of rebound VMT are far outweighed by the overall benefits of the proposal. 
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Table 1. Projected Net GHG Reductions (MMT CO2 Equivalent per year) 

CALENDAR YEAR 2020 2030 2040 2050 

Net reduction to 

tailpipe standards* 165.2 324.6 417.5 518.5

Tailpipe standards 107.7 211.4 274.1 344.0

A/C – indirect CO2 11.0 21.1 27.3 34.2

A/C – direct HFCs 13.5 27.2 32.1 34.9

Upstream 33.1 64.9 84.1 105.5

 

Percent reduction 

relative to U.S. 

reference (cars + light 

trucks) 

12.4% 2.14% 22.8% 22.9%

Percent reduction 

relative to U.S. 

reference (all sectors) 

2.2% 4.2% 5.2% 6.2%

Percent reduction 

relative to worldwide 

reference 

0.3% 0.6% 0.7% 0.9%

 * includes impacts of 10% VMT rebound rate presented in Table III.F.1-3 

Criteria Pollutant Impacts of EPA’s Proposal 

As shown in Table 2, EPA estimates that the proposed program would result in 

reductions of oxides of nitrogen (NOx), volatile organic compounds (VOC), particulate matter 

(PM) and oxides of sulfur (SOx), but would increase carbon monoxide (CO) emissions. The 

CO increase is because gasoline fueled passenger cars and light trucks contribute over 50 

percent of the total CO emissions in the US, whereas for other pollutants the contribution is 

less than 40 percent. Thus, for CO the increase from VMT rebound outweighs the upstream 

CO reductions. For all pollutants the overall impact of the program would be relatively small 

compared to total U.S. inventories across all sectors. In the year 2030, EPA estimates the 

proposed program would reduce these total NOx, PM and SOx inventories by 0.2 to 0.3 

percent and reduce the VOC inventory by 1.2 percent, while increasing the total national CO 

inventory by 0.4 percent. 

As shown in Table 3, EPA estimates that the proposed program would result in small 

changes for toxic emissions compared to total U.S. inventories across all sectors. In 2030, 

EPA estimates the program would reduce total benzene and formaldehyde by 0.04 percent. 

Total acrolein, acetaldehyde, and 1,3-butadiene would increase by 0.03 to 0.2 percent. 
Draft Regulatory Impact Analysis 

xii 

Other factors which may impact criteria, or non-GHG, emissions but are not estimated 

in this analysis include: 

 Vehicle technologies used to reduce tailpipe CO2 emissions; because the 

regulatory standards for non-GHG emissions are the primary driver for these 

emissions, EPA expects the impact of today's program to be negligible on nonGHG emission rates per mile. 

 The potential for increased market penetration of diesel vehicles; because 

these vehicles would be held to the same certification and in-use standards for 

criteria pollutants as their gasoline counterparts, EPA expects their impact to 

be negligible on criteria pollutants and other non-GHG emissions. 

 Early introduction of electric vehicles and plug-in hybrid electric vehicles, 

which would reduce criteria emissions in cases where they are able to certify to 

lower certification standards. It would also likely reduce gaseous air toxics. 

 Reduced refueling emissions due to less frequent refueling events and reduced 

annual refueling volumes resulting from the GHG standards. 

 Increased hot soak evaporative emissions due to the likely increase in number 

of trips associated with VMT rebound modeled in this proposal. 

 Increased market share of E10 relative to E0, due to the decreased overall 

gasoline consumption of today's proposal combined with an unchanged fuel 

ethanol volume. 

Table 2. Annual Criteria Emission Impacts of Program (short tons) 

TOTAL IMPACTS UPSTREAM 

IMPACATS 

DOWNSTREAM 

IMPACTS 

2020 2030 2020 2030 2020 2030 

VOC -73,739 -142,347 -75,437 -147,841 1,698 5,494 

 % of total inventory -0.60% -1.20% -0.61% -1.20% 0.01% 0.05% 

CO 70,614 227,832 -7,209 -14,107 77,823 241,939 

 % of total inventory 0.13% 0.38% -0.01% -0.02% 0.14% 0.40% 

NOX -17,206 -27,726 -22,560 -43,286 5,354 15,560 

 % of total inventory -0.14% -0.20% -0.18% -0.36% 0.04% 0.13% 

PM2.5 -2,856 -5,431 -3,075 -6,003 218 572 

 % of total inventory -0.08% -0.16% -0.09% -0.18% 0.01% 0.02% 

SOx -16,307 -31,965 -13,804 -27,060 -2,503 -4,906 

 % of total inventory -0.18% -0.34% -0.16% -0.29% -0.03% -0.05% 
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Table 3. Annual Air Toxic Emission Impacts of Program (short tons) 

TOTAL IMPACTS UPSTREAM 

IMPACATS 

DOWNSTREAM 

IMPACTS 

2020 2030 2020 2030 2020 2030 

1,3-Butadiene 11 37 -1.8 -3.4 13.2 40.2 

 % of total inventory 0.07% 0.22% -0.01% -0.02% 0.08% 0.24% 

Acetaldehyde 17 61 -8 -15 24.8 75.5 

 % of total inventory 0.04% 0.13% -0.02% -0.03% 0.05% 0.17% 

Acrolein 0 2 -1.1 -2 1.3 3.9 

 % of total inventory 0.00% 0.03% 0.00% 0.00% 0.02% 0.06% 

Benzene -84 -77 -163 -320 79.6 242.2 

 % of total inventory -0.04% -0.04% -0.08% -0.15% 0.04% 0.11% 

Formaldehyde -28 -16 -60 -112 31.8 96.3 

 % of total inventory -0.03% -0.02% -0.07% -0.10% 0.04% 0.11% 

Costs and Benefits of EPA’s Proposal 

Table 4 presents estimated annual net benefits for the indicated calendar years. The 

table also shows the net present values of those net benefits for the calendar years 2012-2050 

using both a 3 percent and a 7 percent discount rate. The table includes the benefits of 

reduced GHG emissions—and consequently the annual net benefits—for each of five interim 

SCC values considered by EPA (please refer to Chapter 7 of this DRIA for a discussion of the 

five interim SCC values). As noted in Chapter 7, there is a very high probability (very likely 

according to the IPCC) that the benefit estimates from GHG reductions are underestimates 

because, in part, models used to calculate SCC values do not include information about 

impacts that have not been quantified. Note that the quantified annual costs shown in Table 4 

are negative because fuel savings are included. Fuel savings are considered as negative costs 

(i.e., positive benefits) of the proposed vehicle program. The fuel savings outweigh the costs 

associated with the addition of new technology and, therefore, the vehicle program costs are 

negative. 
Draft Regulatory Impact Analysis 

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Table 4 Quantified Net Benefits Associated with the Proposed Light-Duty Vehicle GHG Programa, b

(Millions of 2007 dollars) 

 2020 2030 2040 2050 NPV, 3% NPV, 7% 

Quantified Annual 

Costs -$25,100 -$72,500 -$105,700 -$146,100 -$1,287,600 -$529,500 

Quantified Annual Benefits at each assumed SCC value 

SCC 5% $9,900 $21,100 $30,200 $42,100 $400,900 $177,200 

SCC 5% Newell-Pizer $11,200 $24,400 $35,500 $51,600 $470,100 $205,700 

SCC from 3% and 5% $13,400 $29,800 $46,500 $68,600 $594,700 $257,100 

SCC 3% $16,900 $39,800 $62,500 $95,600 $788,600 $337,100 

SCC 3% Newell-Pizer $22,700 $53,800 $87,500 $132,600 $1,093,100 $462,800 

Quantified Net Benefits at each assumed SCC value 

SCC 5% $35,000 $93,600 $135,900 $188,200 $1,688,500 $706,700 

SCC 5% Newell-Pizer $36,300 $96,900 $141,200 $197,700 $1,757,700 $735,200 

SCC from 3% and 5% $38,500 $102,300 $152,200 $214,700 $1,882,300 $786,600 

SCC 3% $42,000 $112,300 $168,200 $241,700 $2,076,200 $866,600 

SCC 3% Newell-Pizer $47,800 $126,300 $193,200 $278,700 $2,380,700 $992,300 a Note that the co-pollutant impacts associated with the standards presented here do not include the full 

complement of endpoints that, if quantified and monetized, would change the total monetized estimate of rulerelated impacts. Instead, the co-pollutant benefits are based on benefit-per-ton values that reflect only human 

health impacts associated with reductions in PM2.5 exposure. Ideally, human health and environmental cobenefits would be based on changes in ambient PM2.5 and ozone as determined by full-scale air quality 

modeling. However, we were unable to conduct a full-scale air quality modeling analysis in time for the 

proposal. We intend to more fully capture the co-pollutant benefits for the analysis of the final standards. b Quantified annual costs are shown as negative here because fuel savings are included. Fuel savings are 

considered as negative costs (i.e., positive benefits) of the proposed vehicle program. The fuel savings outweigh 

the costs associated with the addition of new technology and, therefore, the vehicle program costs are negative. 

The fuel impacts included here were calculated using pre-tax fuel prices. 
Technology Packages, Cost and Effectiveness 

1-1 

CHAPTER 1:Technology Packages, Cost and Effectiveness 

1.1 Overview of Technology 

The proposed GHG program is based on the need to obtain significant GHG emissions 

reductions from the transportation sector, and the recognition that there are cost effective 

technologies to achieve such reductions in the 2012-2016 time frame. As in many prior 

mobile source rulemakings, the decision on what standard to set is largely based on the 

effectiveness of the emissions control technology, the cost (both per manufacturer and per 

vehicle) and other impacts of implementing the technology, and the lead time needed for 

manufacturers to employ the control technology. EPA also considers the need for reductions 

of greenhouse gases, the degree of reductions achieved by the standards, and the impacts of 

the standards in terms of costs, quantified and unquantified benefits, safety, and other impacts. 

The availability of technology to achieve reductions and the cost and other aspects of this 

technology are therefore a central focus of this rulemaking. 

At the same time, the technological problems and solutions involved in this 

rulemaking differ in many ways from prior mobile source rulemakings. In the past the 

assessment of exhaust emissions control technology has focused on how to reduce the amount 

of various unwanted chemical compounds that are generated when fuel is combusted. The 

emissions are often the result of incomplete combustion, such as emissions of HC, CO, and 

PM. In some cases the combustion products are the result of the specific conditions under 

which combustion occurs, such as the relationship between emissions of NOx and the 

temperature of combustion. Technology to control exhaust emissions has focused, in part, on 

changing the fuel delivery and engine systems so there is more complete combustion of the 

fuel which generates less HC, CO, and PM in the engine exhaust but, by design, generates 

more CO2. (CO2 is one of ultimate combustion products of any carbon containing fuel, such 

as gasoline and diesel fuel.). Other changes to the fuel delivery and engine systems have 

been designed to change the combustion process to reduce the amount of NOx and PM 

generated by the engine. Very large reductions have been achieved by installing and 

optimizing aftertreatment (post-combustion, post- engine generated pollution) devices, such 

as catalytic converters and catalyzed diesel particulate filters (DPF), that reduce the amount of 

emissions of HC, CO, and PM by oxidizing or combusting these compounds in the 

aftertreatment device, again generating CO2 in the process. In the case of NOx, 

aftertreatment devices have focused on the chemical process of reduction, or removal of 

oxygen from the compound. Therefore the exhaust emissions control technologies of the past 

have focused almost exclusively on (1) upgrading the fuel delivery and engine systems to 

control the combustion process to reduce the amount of unwanted emissions from the engine 

and in the process increase the amount of CO2 emitted, and on (2) aftertreatment devices that 

either continue this oxidation process and increase emissions of CO2, or otherwise change the 

compounds emitted by the engine. Since CO2 is a stable compound produced by the complete 

combustion of the fuel – indeed serving as a marker of how efficiently fuel has been 

combusted, these two methods employed to address HC, CO, PM, and NOx are not available 
Draft Regulatory Impact Analysis 

1-2 

to address CO2. Instead, the focus of the CO2 emissions control technology must be entirely 

different—reducing the amount of fuel that is combusted. 

Vehicles combust fuel to perform two basic functions: 1) transport the vehicle, its 

passengers and its contents, and 2) operate various accessories during the operation of the 

vehicle such as the air conditioner. Technology can reduce CO2 emissions by either making 

more efficient use of the energy that is produced through combustion of the fuel or reducing 

the energy needed to perform either of these functions. 

This focus on efficiency involves a major change in focus and calls for looking at the 

vehicle as an entire system. In addition to fuel delivery, combustion, and aftertreatment 

technology, any aspect of the vehicle that affects the need to produce energy must also be 

considered. For example, the efficiency of the transmission system, which takes the energy 

produced by the engine and transmits it to the wheels, and the resistance of the tires to rolling 

both have major impacts on the amount of fuel that is combusted while operating the vehicle. 

The braking system the aerodynamics of the vehicle and the efficiency of accessories, such as 

the air conditioner, all affect how much fuel is combusted. 

This need to focus on the efficient use of energy by the vehicle as a system leads to a 

broad focus on a wide variety of technologies that affect almost all the systems in the design 

of a vehicle. As discussed below, there are many technologies that are currently available 

which can reduce vehicle energy consumption. These technologies are already being 

commercially utilized to a limited degree in the current light-duty fleet. These technologies 

include hybrid technologies that use higher efficiency electric motors as the power source in 

combination with or instead of internal combustion engines. While already commercialized, 

hybrid technology continues to be developed and offers the potential for even greater 

efficiency improvements. Finally, there are other advanced technologies under development, 

such as lean burn gasoline engines, which offer the potential of improved energy generation 

through improvements in the basic combustion process. 

The large number of possible technologies to consider and the breadth of vehicle 

systems that are affected mean that consideration of the manufacturer’s design and production 

process plays a major role in developing the proposed standards. Vehicle manufacturers 

typically develop their many different models by basing them on a limited number of vehicle 

platforms. Several different models of vehicles are produced using a common platform, 

allowing for efficient use of design and manufacturing resources. The platform typically 

consists of common vehicle architecture and structural components. Given the very large 

investment put into designing and producing each vehicle model, manufacturers typically plan 

on a major redesign for the models approximately every 5 years. At the redesign stage, the 

manufacturer will upgrade or add all of the technology and make all of the other changes 

needed so the vehicle model will meet the manufacturer’s plans for the next several years. 

This includes meeting all of the emissions and other requirements that would apply during the 

years before the next major redesign of the vehicle. 

This redesign often involves a package of changes, designed to work together to meet 

the various requirements and plans for the model for several model years after the redesign. 

This often involves significant engineering, development, manufacturing, and marketing 
Technology Packages, Cost and Effectiveness 

1-3 

resources to create a new product with multiple new features. In order to leverage this 

significant upfront investment, manufacturers plan vehicle redesigns with several model 

years’ of production in mind. Vehicle models are not completely static between redesigns as 

limited changes are often incorporated for each model year. This interim process is called a 

refresh of the vehicle and generally does not allow for major technology changes although 

more minor ones can be done (e.g., aerodynamic improvements, valve timing improvements). 

More major technology upgrades that affect multiple systems of the vehicle thus occur at the 

vehicle redesign stage and not in the time period between redesigns. 

As discussed below, there are a wide variety of emissions control technologies 

involving several different systems in the vehicle that are available for consideration. Many 

can involve major changes to the vehicle, such as changes to the engine block and heads, or 

redesign of the transmission and its packaging in the vehicle. This calls for tying the 

incorporation of the emissions control technology into the periodic redesign process. This 

approach would allow manufacturers to develop appropriate packages of technology upgrades 

that combine technologies in ways that work together and fit with the overall goals of the 

redesign. It also allows the manufacturer to fit the process of upgrading emissions control 

technology into its multi-year planning process, and it avoids the large increase in resources 

and costs that would occur if technology had to be added outside of the redesign process. 

Over the five model years at issue in this rulemaking, 2012-2016, EPA projects that 

almost the entire fleet of light-duty vehicles (i.e., 85 percent) will have gone through a 

redesign cycle. If the technology to control greenhouse gas emissions is efficiently folded 

into this redesign process, then by 2016 almost the entire light-duty fleet could be designed to 

employ upgraded packages of technology to reduce emissions of CO2, and as discussed 

below, to reduce emissions of HFCs from the air conditioner. 

In determining the requisite technology and cost of these first ever GHG emissions 

standards for light-duty vehicles, EPA proposes to use an approach that accounts for and 

builds on this redesign process. This provides the opportunity for several control technologies 

to be incorporated into the vehicle during redesign, achieving significant emissions reductions 

from the model at one time. This is in contrast to what would be a much more costly 

approach of trying to achieve small increments of reductions over multiple years by adding 

technology to the vehicle piece by piece outside of the redesign process. 

As described below, the vast majority of technology required by the GHG proposal is 

commercially available and already being employed to a limited extent across the fleet. The 

vast majority of the emission reductions which would result from the proposed rule would 

result from the increased the use of these technologies. EPA also believes the proposed rule 

would encourage the development and limited use of more advanced technologies, such as 

PHEVs and EVs. 

In section 1.2 below, a summary of technology costs and effectiveness is presented. In 

section 1.3, the process of combining technologies into packages is described along with 

package costs and effectiveness. Sections 1.4 through 1.6 discuss the lumped parameter 

approach which provides background and support for determining technology and package 

effectiveness. 
Draft Regulatory Impact Analysis 

1-4 

1.2 Technology Cost and Effectiveness 

EPA collected information on the cost and effectiveness of CO2 emission reducing 

technologies from a wide range of sources. The primary sources of information were 

NHTSA’s 2011 CAFE FRM and EPA’s 2008 Staff Technical Report. In those analyses, 

piece costs and effectiveness were estimated based on a number of sources. The objective 

was to use those sources of information considered to be most credible. Those sources 

included: the 2002 NAS report on the effectiveness and impact of CAFE standards; the 2004 

study done by the Northeast States Center for a Clean Air Future (NESCCAF); the 

California Air Resources Board (CARB) Initial Statement of Reasons in support of their 

carbon rulemaking; a 2006 study done by Energy and Environmental Analysis (EEA) for the 

Department of Energy; a study done by the Martec Group for the Alliance of Automobile 

Manufacturers, and an update by the Martec Group to that study; and vehicle fuel economy 

certification data. In addition, confidential data submitted by vehicle manufacturers in 

response to NHTSA’s request for product plans were considered, as was confidential 

information shared by automotive industry component suppliers in meetings with EPA and 

NHTSA staff held during the second half of the 2007 calendar year. These confidential data 

sources were used primarily as a validation of the estimates since EPA prefers to rely on 

public data rather than confidential data. EPA also has a contracted study ongoing with FEV 

(an engineering services firm) that consists of complete system tear-downs to evaluate 

technologies down to the nuts and bolts to arrive at very detailed estimates of the costs 

associated with manufacturing them. Lastly, cost and effectiveness estimates have been 

adjusted slightly as a result of further meetings between EPA and NHTSA staff in the first 

half of 2009 where both piece costs and fuel consumption efficiencies were discussed in 

detail. EPA also reviewed the published technical literature which addressed the issue of CO2

emission control, such as papers published by the Society of Automotive Engineers and the 

American Society of Mechanical Engineers. The results of all of the research and discussions 

are summarized in Chapter 3 of the draft Joint Technical Support Document. 

EPA reviewed all this information in order to develop the best estimates of the cost 

and effectiveness of CO2 reducing technologies. These estimates were developed for five 

vehicle classes: small car, large car, minivan, small truck and large truck. All vehicle types 

were mapped into one of these five classes in EPA’s analysis (see Chapter 3 of the draft Joint 

TSD). Fuel consumption reductions are possible from a variety of technologies whether they 

be engine-related (e.g., turbocharging), transmission-related (e.g., six forward gears in place 

of four), accessory-related (e.g., electronic power steering), or vehicle-related (e.g., low 

rolling resistance tires). Table 1-1 through Table 1-5 show estimates of the near term cost 

associated with various technologies for the five vehicle classes used in this analysis. These 

estimates shown in Table 1-1 through Table 1-5 are relative to a baseline vehicle having a 

multi-point, port fuel injected gasoline engine operating at a stoichiometric air-fuel ratio with 

fixed valve timing and lift and without any turbo or super charging and equipped with a 4-

speed automatic transmission. This configuration was chosen as the baseline vehicle because 

it is the predominant technology package sold in the United States. Costs are presented in 

terms of their hardware incremental compliance cost. This means that they include all 

potential costs associated with their application on vehicles, not just the cost of their physical 

parts. A more detailed description of these and the following estimates of cost and 
Technology Packages, Cost and Effectiveness 

1-5 

effectiveness of CO2 reducing technologies can be found in Chapter 3 of the draft joint TSD, 

along with a more detailed description of the comprehensive technical evaluation underlying 

the estimates. 

Table 1-1 EPA’s Incremental Piece Costs for Engine Technologies Marked up to include both Direct and 

Indirect Costs in 2016 (2007 Dollars per Vehicle) 

Vehicle Class Technology Incremental to Small Car Large Car Minivan Small Truck Large Truck 

Low friction lubricants Base engine $3 $3 $3 $3 $3 

 Engine friction reduction Base engine $50 $75 $75 $75 $100 

VVT – intake cam 

phasing Base engine $40 $80 $80 $80 $80 

VVT – coupled cam 

phasing Base engine $40 $80 $80 $80 $80 

VVT – dual cam phasing Base engine $73 $157 $157 $157 $157 

Cylinder deactivation Base engine n/a $150 $150 $150 $169 

Discrete VVLT Base engine $125 $181 $181 $181 $259 

OHC Engines 

Continuous VVLT Base engine $245 $449 $449 $449 $489 

Cylinder deactivation Base engine n/a $150 $150 $150 $169 

VVT – coupled cam 

phasing Base engine $40 $40 $40 $40 $40 

Discrete VVLT Base engine $141 $204 $204 $204 $291 

OHV Engines 

Continuous VVLT 

(includes conversion to 

Overhead Cam) 

Base engine w/ VVTcoupled $497 $1,048 $1,048 $1,048 $1,146 

 Camless valvetrain 

(electromagnetic) Base engine $501 $501 $501 $501 $501 

 GDI – stoichiometric Base engine $222 $287 $287 $287 $312 

 GDI – lean burn GDI - stoich $623 $623 $623 $623 $623 

Turbocharge (single) Base engine $366 $366 $366 $366 $366 

Turbocharge (twin) Base engine $663 $663 $663 $663 $663 

Downsize to I4 DOHC V6 DOHC -$337 -$337 -$337 -$337 -$337 

Downsize to I4 DOHC V6 SOHC -$53 -$53 -$53 -$53 -$53 

Downsize to I4 DOHC V6 OHV $265 $265 $265 $265 $265 

Downsize to I4 DOHC I4 DOHC (larger) -$47 -$47 -$47 -$47 -$47 

Downsize to I3 DOHC I4 DOHC -$80 n/a n/a n/a n/a 

Downsize to V6 DOHC V8 DOHC n/a -$160 -$160 -$160 -$160 

Downsize to V6 DOHC V8 SOHC 2V n/a $199 $199 $199 $199 

Downsize to V6 DOHC V8 SOHC 3V n/a $111 $111 $111 $111 

Turbo w/o downsize 

Downsize w/o turbo 

Downsize to V6 DOHC V8 OHV n/a $310 $310 $310 $310 

Downsize to I4 DOHC 

& add turbo V6 DOHC w/o turbo $214 $214 $214 $214 $214 

Downsize to I4 DOHC 

& add turbo V6 SOHC w/o turbo $453 $453 $453 $453 $453 

Downsize to I4 DOHC 

& add turbo V6 OHV w/o turbo $797 $797 $797 $797 $797 

Downsize to I4 DOHC 

& add turbo 

I4 DOHC (larger) 

w/o turbo $372 $372 $372 $372 $372 

Downsize to I3 DOHC 

& add turbo I4 DOHC w/o turbo $344 n/a n/a n/a n/a 

Downsize to V6 DOHC 

& add twin turbo V8 DOHC w/o turbo n/a $613 $613 $613 $613 

Downsize to V6 DOHC 

& add twin turbo 

V8 SOHC 2V w/o 

turbo n/a $971 $971 $971 $971 

Downsize to V6 DOHC 

& add twin turbo 

V8 SOHC 3V w/o 

turbo n/a $872 $872 $872 $872 

Turbo with downsize 

Downsize to V6 DOHC V8 OHV w/o turbo n/a $1,096 $1,096 $1,096 $1,096 
Draft Regulatory Impact Analysis 

1-6 

& add twin turbo 

 Convert to V6 DOHC V6 SOHC n/a $354 $354 $354 $354 

 Convert to V6 DOHC V6 OHV n/a $464 $464 $464 $464 

 Convert to V8 DOHC V8 SOHC 2V n/a $398 $398 $398 $398 

 Convert to V8 DOHC V8 SOHC 3V n/a $310 $310 $310 $310 

 Convert to V8 DOHC V8 OHV n/a $509 $509 $509 $509 

 Gasoline HCCI dualmode GDI - stoich $253 $375 $375 $375 $659 

 Diesel – Lean NOx trap Base gasoline engine 

 Diesel – urea SCR Base gasoline engine $2,655 $2,164 $2,164 $2,961 

Table 1-2 EPA’s Incremental Piece Costs for Transmission Technologies Marked up to include both 

Direct and Indirect Costs in 2016 (2007 Dollars per Vehicle) 

Vehicle Class 

Technology Incremental to Small 

Car 

Large 

Car Minivan Small 

Truck 

Large 

Truck 

Aggressive shift logic Base trans $28 $28 $28 $28 $28 

Early torque converter lockup Base trans $25 $25 $25 $25 $25 

5-speed automatic 4-speed auto trans $90 $90 $90 $90 $90 

6-speed automatic 4-speed auto trans $150 $150 $150 $150 $150 

6-speed DCT – dry clutch 6-speed auto trans $65 $65 $65 $65 $65 

6-speed DCT – wet clutch 6-speed auto trans $139 $139 $139 $139 $139 

6-speed manual 5-speed manual trans $79 $79 $79 $79 $79 

CVT 4-speed auto trans $192 $224 $224 n/a n/a 

Table 1-3 EPA’s Incremental Piece Costs for Hybrid Technologies Marked up to include both Direct and 

Indirect Costs in 2016 (2007 Dollars per Vehicle) 

Vehicle Class Technology Incremental to Small Car Large Car Minivan Small Truck Large Truck 

Stop-Start Base engine & 

trans $351 $398 $398 $398 $437 

IMA/ISA/BSG 

(includes engine 

downsize) 

Base engine & 

trans $2,854 $3,612 $3,627 $3,423 $4,431 

2-Mode hybrid 

electric vehicle 

Base engine & 

trans $4,232 $5,469 $5,451 $4,943 $7,236 

Power-split 

hybrid electric 

vehicle 

Base engine & 

trans $3,967 $5,377 $5,378 $4,856 $7,210 

Full-Series 

hydraulic hybrid 

Base engine & 

trans $750 $825 $825 $900 $1200 

Plug-in hybrid 

electric vehicle 

IMA/ISA/BSG 

hybrid $6,922 $9,519 $9,598 $9,083 $12,467 

Plug-in hybrid 

electric vehicle 

Power-split 

hybrid $5,423 $7,431 $7,351 $7,128 $9,643 

Full electric 

vehicle 

Base engine & 

trans $27,628 n/a n/a n/a n/a 
Technology Packages, Cost and Effectiveness 

1-7 

Table 1-4 EPA’s Incremental Piece Costs for Accessory Technologies Marked up to include both Direct 

and Indirect Costs in 2016 (2007 Dollars per Vehicle) 

Vehicle Class Technology Incremental to Small Car Large Car Minivan Small Truck Large Truck 

Improved high efficiency 

alternator & 

electrification of 

accessories 

Base accessories $76 $76 $76 $76 $76 

Upgrade to 42 volt 

electrical system 

12 volt electrical 

system $86 $86 $86 $86 $86 

Electric power steering 

(12 or 42 volt) 

Base power 

steering $94 $94 $94 $94 $94 

Table 1-5 EPA’s Incremental Piece Costs for Vehicle Technologies Marked up to include both Direct and 

Indirect Costs in 2016 (2007 Dollars per Vehicle) 

Vehicle Class Technology Incremental to Small Car Large Car Minivan Small Truck Large Truck 

Aero drag reduction (20% 

on cars, 10% on trucks) Base vehicle $42 $42 $42 $42 $42 

Low rolling resistance 

tires Base tires $6 $6 $6 $6 $6 

Low drag brakes (ladder 

frame only) Base brakes n/a n/a n/a $63 $63 

Secondary axle disconnect 

(unibody only) Base vehicle $514 $514 $514 $514 n/a 

Front axle disconnect 

(ladder frame only) Base vehicle n/a n/a n/a $84 $84 

Table 1-6 through Table 1-10 summarize the CO2 reduction estimates of various 

technologies which can be applied to cars and light-duty trucks. A similar summary of costs 

is provided in Chapter 3 of the draft joint TSD and each of these estimates is discussed in 

more detail there. 
Draft Regulatory Impact Analysis 

1-8 

Table 1-6 Engine Technology Effectiveness 

Absolute CO2 Reduction (% from baseline vehicle) 

Technology Small Car Large 

Car Minivan Small 

Truck 

Large 

Truck 

Low friction lubricants – incremental to base engine 0.5 0.5 0.5 0.5 0.5 

Engine friction reduction – incremental to base engine 1-3 1-3 1-3 1-3 1-3 

Overhead Cam Branch 

VVT – intake cam phasing 2 1 1 1 2 

VVT – coupled cam phasing 3 4 2 3 4 

VVT – dual cam phasing 3 4 2 2 4 

Cylinder deactivation (includes imp. oil pump, 

if applicable) n.a. 6 6 6 6 

Discrete VVLT 4 3 3 4 4 

Continuous VVLT 5 6 4 5 5 

Overhead Valve Branch 

Cylinder deactivation (includes imp. oil 

pump, if applicable) n.a. 6 6 6 6 

VVT – coupled cam phasing 3 4 2 3 4 

Discrete VVLT 4 4 3 4 4 

Continuous VVLT (includes conversion to 

Overhead Cam) 5 6 4 5 5 

Camless valvetrain (electromagnetic) ** 5-15 5-15 5-15 5-15 5-15 

Gasoline Direct Injection–stoichiometric (GDI-S) 1-2 1-2 1-2 1-2 1-2 

Gasoline Direct Injection–lean burn (incremental to 

GDI-S) ** 8-10 9-12 9-12 9-12 10-14 

Gasoline HCCI dual-mode (incremental to GDI-S) ** 10-12 10-12 10-12 10-12 10-12 

Turbo+downsize (incremental to GDI-S) 5-7 5-7 5-7 5-7 5-7 

Diesel – Lean NOx trap[ ]* 15-26 

[25-35] 

21-32 

[30-40] 

21-32 

[30-40] 

21-32 

[30-40] 

21-32 

[30-40] 

Diesel – urea SCR [ ]* 15-26 

[25-35] 

21-32 

[30-40] 

21-32 

[30-40] 

21-32 

[30-40] 

21-32 

[30-40] 

* Note: estimates for % reduction in fuel consumption are presented in brackets. 

** Note: for reference only, not used in this rulemaking 
Technology Packages, Cost and Effectiveness 

1-9 

Table 1-7 Transmission Technology Effectiveness 

Absolute CO2 Reduction (% from baseline vehicle) 

Technology Small 

Car 

Large 

Car Minivan Small 

Truck 

Large 

Truck 

 5-speed automatic (from 4-speed auto) 2.5 2.5 2.5 2.5 2.5 

 Aggressive shift logic 1-2 1-2 1-2 1-2 1-2 

 Early torque converter lockup 0.5 0.5 0.5 0.5 0.5 

 6-speed automatic (from 4-speed auto) 4.5-6.5 4.5-6.5 4.5-6.5 4.5-6.5 4.5-6.5 

 6-speed AMT (from 4-speed auto) 9.5-14.5 9.5-14.5 9.5-14.5 9.5-14.5 9.5-14.5 

 6-speed manual (from 5-speed manual) 0.5 0.5 0.5 0.5 0.5 

 CVT (from 4-speed auto) 6 6 6 n.a. n.a. 

Table 1-8 Hybrid Technology Effectiveness 

Absolute CO2 Reduction (% from baseline vehicle) 

Technology Small 

Car 

Large 

Car Minivan Small 

Truck 

Large 

Truck 

 Stop-Start with 42 volt system 7.5 7.5 7.5 7.5 7.5 

 IMA/ISA/BSG (includes engine downsize) 30 25 20 20 20 

 2-Mode hybrid electric vehicle n.a. 40 40 40 25 

 Power-split hybrid electric vehicle 35 35 35 35 n.a. 

 Full-Series hydraulic hybrid 40 40 40 40 30 

 Plug-in hybrid electric vehicle 58 58 58 58 47 

 Full electric vehicle (EV) 100 100 n.a. n.a. n.a. 

Table 1-9 Accessory Technology Effectiveness 

Absolute CO2 Reduction (% from baseline vehicle) 

Technology Small 

Car 

Large 

Car Minivan Small 

Truck 

Large 

Truck 

Improved high efficiency alternator & electrification of 

accessories (12 volt) 1-2 1-2 1-2 1-2 1-2 

Electric power steering (12 or 42 volt) 1.5 1.5-2 2 2 2 

Improved high efficiency alternator & electrification of 

accessories (42 volt) 2-4 2-4 2-4 2-4 2-4 

Table 1-10 Other Vehicle Technology Effectiveness 

Absolute CO2 Reduction (% from baseline vehicle) 

Technology Small 

Car 

Large 

Car Minivan Small 

Truck 

Large 

Truck 

 Aero drag reduction (20% on cars, 10% on trucks) 3 3 3 2 2 

 Low rolling resistance tires (10%) 1-2 1-2 1-2 1-2 n.a. 

 Low drag brakes (ladder frame only) n.a. n.a. n.a. 1 1 

 Secondary axle disconnect (unibody only) 1 1 1 1 n.a. 

 Front axle disconnect (ladder frame only) n.a. n.a. n.a. 1.5 1.5 
Draft Regulatory Impact Analysis 

1-10 

1.3 Package Cost and Effectiveness 

1.3.1 Explanation of Technology Packages 

Individual technologies can be used by manufactures to achieve incremental CO2

reductions. However, as mentioned in Section 1.1, EPA believes that manufacturers are more 

likely to bundle technologies into “packages” to capture synergistic aspects and reflect 

progressively larger CO2 reductions with additions or changes to any given package. In 

addition, manufacturers typically apply new technologies in packages during model 

redesigns—which occur once roughly every five years—rather than adding new technologies 

one at a time on an annual or biennial basis. This way, manufacturers can more efficiently 

make use of their redesign resources and more effectively plan for changes necessary to meet 

future standards. 

Therefore, the approach taken here is to group technologies into packages of 

increasing cost and effectiveness. EPA determined that 19 different vehicle types provided 

adequate resolution required to accurately model the entire fleet. This was the result of 

analyzing the existing light duty fleet with respect to vehicle size and powertrain 

configurations. All vehicles, including cars and trucks, were first distributed based on their 

relative size, starting from compact cars and working upward to large trucks. Next, each 

vehicle was evaluated for powertrain, specifically the engine size, I4, V6, and V8, and finally 

by the number of valves per cylinder. Note that each of these 19 vehicle types was mapped 

into one of the five classes of vehicles mentioned in Figure 1-1. While the five classes 

provide adequate resolution for the cost basis associated with technology application, they do 

not adequately account for all vehicle attributes such as base vehicle powertrain configuration 

and mass reduction. For example, costs and effectiveness estimates for the small car class 

were used to represent costs for three vehicle types: subcompact cars, compact cars, and 

small multi-purpose vehicles (MPV) equipped with a 4-cylinder engine, however the mass 

reduction associated for each of these vehicle types was based on the vehicle type sales 

weighted average. Note also that these 19 vehicle types span the range of vehicle footprints—

smaller footprints for smaller vehicles and larger footprints for larger vehicles—which serve 

as the basis for the proposed GHG standards. 

Within each of the 19 vehicle types multiple technology packages were created in 

increasing technology content and, hence, increasing effectiveness. Important to note is that 

the effort in creating the packages attempted to maintain a constant utility for each package as 

compared to the baseline package. As such, each package is meant to provide equivalent 

driver-perceived performance to the baseline package. The initial packages represent what a 

manufacturer will most likely implement on all vehicles, including low rolling resistance tires, 

low friction lubricants, engine friction reduction, aggressive shift logic, early torque converter 

lock-up, improved electrical accessories, and low drag brakes. Subsequent packages include 

advanced gasoline engine and transmission technologies such as turbo/downsizing, GDI, mass 

reduction and dual-clutch transmission. The most technologically advanced packages within 

a segment included HEV, PHEV and EV designs. The end result being a list of several 

packages for each of 19 different vehicle types from which a manufacturer could choose in 

order to modify its fleet such that compliance could be achieved. 
Technology Packages, Cost and Effectiveness 

1-11 

The final step in creating the vehicle packages was to evaluate each package within 

the 19 vehicle types for cost-effectiveness. This was accomplished by dividing the 

incremental cost of the technology package by its incremental effectiveness and assessing the 

overall step in cost-effectiveness. Technology packages that demonstrated little to no increase 

in effectiveness and a significant increase in cost were eliminated as a choice for the model. 

This process provided several positive aspects in the package creation: 

(1) Vehicle packages were not limited by any preconceived assumptions of which 

technologies should be more prominent. An example of this is turbo-downsizing a 

V6 engine. In some cases the GDI V6 with advanced valvetrain technology was 

just as effective as a turbo charge I4, thus excluding the additional cost of turbo 

charging; 

(2) The OMEGA model was allowed to apply packages in an increasing order of both 

effectiveness and cost. 

 Some of the intermediate packages were not cost-effective. As a result, the model 

might be blocked from choosing a subsequent package that was cost-effective. Most of the 

diesel packages and some of the hybrid packages exhibited this condition. Due to the high 

cost of these packages, and effectiveness on par with advanced gas, the model would not 

move through these packages and choose a more cost effective package, thus blocking the 

model’s logical progression. This is the reason for the absence of diesel and hybrid packages 

in some of the 19 vehicle types available for the OMEGA model. The specific criteria used to 

remove certain packages from use the model inputs is discussed further below. It is important 

to note that the burning of diesel fuel generates approximately 15% more CO2 than gasoline. 

As this rule is based on the reduction of CO2 emissions and not on fuel economy, this creates 

an additional effectiveness disadvantage for the diesel packages as compared to the advanced 

gas and gas hybrid packages. 

Small car

Subcompact; 16V I4 DOHC (T1)

Large car

Minivan

Small 

truck

Large 

truck

Compact; 16V I4 DOHC (T2)

Midsize car/small MPV; 16V I4 DOHC (T3)

Midsize/large car; 24V V6 DOHC (T5)

Midsize/large car; 32V V8 DOHC (T6) Compact car/small MPV; 24V V6 DOHC (T4)

Midsize MPV/small truck; 16V I4 DOHC (T7)

Large MPV; 12V V6 SOHC (T9)

Large MPV; 16V V8 SOHC (T10)

Large MPV; 24V V6 DOHC (T16)

Large MPV; 32V V8 DOHC (T17)

Midsize MPV/small truck; 12V V6 SOHC (T8)

Midsize MPV/small truck; 24V V6 DOHC (T15)

Large truck; 12V V6 SOHC (T11)

Large truck/MPV; 12V V6 OHV (T12)

Large truck; 16V V8 OHV (T13)

Large truck/van; 16V V8 SOHC (T14)

Large truck/van; 24V V6 DOHC (T18)

Large truck/van; 32V V8 DOHC (T19)

Figure 1-1 Scaling classes to Vehicle Type Mapping 
Draft Regulatory Impact Analysis 

1-12 

1.3.2 Technology Package Costs & Effectiveness 

As described above, technology packages were created for each of 19 different vehicle 

types. These packages are described in Table 1-11 and the 2016 MY costs for each package 

are also presented. Note that Table 1-11 includes all the packages created and considered by 

EPA. Only a subset of these packages was actually used as inputs to the OMEGA model 

because some of the packages were not desirable from a cost effectiveness standpoint (in 

other words, some packages would be skipped over if the next package provide more 

attractive cost effectiveness). Table 1-12 shows the package costs for the packages that were 

actually used as inputs to the OMEGA model (note that all packages are listed but only those 

for which costs are shown were actually used in the OMEGA model). This table shows the 

package costs for each model year 2012 through 2022 and later. This shows the impact of 

both learning effects and short-term versus long-term indirect cost markups on the package 

costs. For details of the learning effects and indirect cost markups used in this analysis refer 

to Chapter 3 of the draft joint TSD. By taking a simple average of the technology package 

costs for each year shown in Table 1-12 and then normalizing the averages to the 2016 model 

year average, the package costs for each year can be expressed as a percentage relative to 

2016. These results are shown in Table 1-13. This table shows that package costs are, on 

average, 117% of the costs for 2016. This higher cost is due to backing out the learning 

effects that are built into the 2016 model year estimates. For 2014, the costs are 108% of 

those for 2016 as learning has occurred between 2012 and 2014. The costs for 2022 are 92% 

of those for 2016. This is the result of the long-term ICM kicking in as some indirect costs 

are no longer attributable to the proposed program. Table 1-12 also shows the effectiveness 

of each package used in the OMEGA model (note that the effectiveness of packages does not 

change with model year). 
Technology Packages, Cost and Effectiv

1-13 

Table 1-11 Package Descriptions and 2016MY Costs for 19 Vehicle Types (T1-T19), All Packages Considered, Costs in 2007 dollars 

Vehicle

Technology

Package Engine Transmission System Voltage

Camshaft changes

(excluding those for 

downsized engines) Lubes

Friction Rdxn

Downsize

Aftertreatment

Aggressive shift

Early torque lock

Alternator & electrificati

o

Power steering

Aero

Low RR tires

Low drag brakes

Axle disconnect

baseline 1.5L - 4V DOHC I4 AT 4 spd 12 V1 1.5L - 4V I4 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR 2 1.5L - 4V I4 CCP DCT 6 spd 12 V LUB EFR IACC 12V EPS AERO 1 LRR 3 1.2L I3 DVVL + CCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I3 IACC 42V EPS AERO 1 LRR 4 0.7L I3 (small) Turbo DCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I3 IACC 42V EPS AERO 1 LRR 5 150kW/lithium ion (range of FTP 150 miles) N/A HEV AERO 1 LRR baseline 2.4L-4V DOHC I4 AT 4 spd 12 V1 2.4L 4V I4 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR 2 2.0L I4 CCP + GDI AT 6 spd 12 V LUB EFR I4 to I4 ASL TORQ IACC 12V EPS AERO 1 LRR 3 2.4L -4V I4 CCP + GDI DCT 6 spd 12 V LUB EFR I4 to I4 IACC 12V EPS AERO 1 LRR 4 2.0L I4 DVVL + CCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I4 IACC 42V EPS AERO 1 LRR 5 1.5L I4 Turbo DCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I4 IACC 42V EPS AERO 1 LRR 6 1.2L I4 HEV (IMA) + GDI dry DCT 6 spd HEV LUB EFR I4 to I4 AERO 1 LRR 7 1.2L I4 HEV Plug-in IMA + GDI dry DCT 6 spd HEV LUB EFR I4 to I4 AERO 1 LRR baseline 2.4L-4V DOHC I4 AT 4 spd 12 V1 2.4L - 4V I4 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR 2 2.2L I4 CCP + GDI AT 6 spd 12 V LUB EFR I4 to I4 ASL TORQ IACC 12V EPS AERO 1 LRR 3 2.2L I4 DVVL + CCP + GDI DCT 6 spd 12 V LUB EFR I4 to I4 IACC 12V EPS AERO 1 LRR 4 2.2L I4 DVVL + CCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I4 IACC 42V EPS AERO 1 LRR 5 1.6L I4 Turbo DCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I4 IACC 42V EPS AERO 1 LRR 6 1.6L Turbo DCP + GDI lean burn dry DCT 6 spd 42 S-S LUB EFR I4 to I4 GDI-LB IACC 42V EPS AERO 1 LRR 7 1.4L I4 Turbo HEV (IMA) + GDI dry DCT 6 spd HEV LUB EFR I4 to I4 AERO 1 LRR 8 1.8L I4 HEV (Power Split) + GDI N/A HEV LUB EFR I4 to I4 AERO 1 LRR 9 1.8L I4 HEV Plug-in Power Split + GDI N/A HEV LUB EFR I4 to I4 AERO 1 LRR baseline 3.0L-4V DOHC V6 AT 4 spd 12 V

1 3.0L - 4V V6 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR 

2 2.0L I4 Turbo DCP + GDI AT 6 spd 12 V LUB EFR V6 DOHC to I4 ASL TORQ IACC 12V EPS AERO 1 LRR 3 2.0L I4 Turbo DCP + GDI DCT 6 spd 12 V LUB EFR V6 DOHC to I4 IACC 12V EPS AERO 1 LRR 4 2.0L I4 Turbo DCP + GDI DCT 6 spd 42 S-S LUB EFR V6 DOHC to I4 IACC 42V EPS AERO 1 LRR 5 2.0L Turbo DCP + GDI lean burn DCT 6 spd 42 S-S LUB EFR V6 DOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR 6 2.4L I4 Turbo Diesel DCT 6 spd LUB EFR Diesel-SCR EPS AERO 1 LRR 7 1.5L I4 Turbo HEV (IMA) + GDI DCT 6 spd HEV LUB EFR V6 DOHC to I4 AERO 1 LRR 8 2.8L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR AERO 1 LRR 

Subcomp

I4 (T1)

Compact Car 

I4 (T2)

Midsize Car/Small MPV 

(unibody)

I4 (T3)

Compact Car/Small 

MPV (unibody)

V6 (T4)
Draft Regulatory Impact Analysis 

1-14 

Table 1-11 Continued 

baseline 3.3L-4V DOHC V6 AT 4 spd 12 V

1 3.3L - 4V V6 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $21

2 3.0L V6 GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,02

3 3.0L V6 w/ Deac GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,27

4 3.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR 10% $2,105 2.2L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 DOHC to I4 IACC 42V EPS AERO 1 LRR 10% $2,246 3.0L V6 HCCI GDI DCT 6spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR 30% $3,757 2.2L Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V6 DOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR 30% $4,37

8 2.5L I4 HEV (Power Split) + GDI N/A HEV LUB EFR V6 DOHC to I4 AERO 1 LRR $6,00baseline 4.5L-4V DOHC V8 AT 4 spd 12 V

1 4.5L - 4V V8 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $21

2 4.0L V6 GDI + CCP AT 6 spd 12 V LUB EFR V8 DOHC to V6 DOHC ASL TORQ IACC 12V EPS AERO 1 LRR 3% $88

3 4.0L V6 w/ Deac GDI + CCP AT 6 spd 42 S-S LUB EFR V8 DOHC to V6 DOHC ASL TORQ IACC 42V EPS AERO 1 LRR 5% $1,63

4 4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 5% $1,71

5 3.0L V6 Turbo DCP + GDI AT 6 spd 42 S-S LUB EFR V8 DOHC to V6 DOHC ASL TORQ IACC 42V EPS AERO 1 LRR 5% $2,33

6 3.0L V6 Turbo DCP + GDI DCT 6 spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 5% $2,41

7 4.0L V6 HCCI GDI DCT 6 spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 30% $3,85

8 3.0L V6 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR 5% $3,45

9 3.0L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR V8 DOHC to V6 DOHC AERO 1 LRR $5,95

baseline 2.6L-4V DOHC I4 (I5) AT 4 spd 12 V1 2.6 L - 4V I4 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $21

2 2.4L I4 CCP + GDI AT 6 spd 12 V LUB EFR I4 to I4 ASL TORQ IACC 12V EPS AERO 1 LRR 3% $98

3 2.4L I4 DVVL + CCP + GDI DCT 6 spd 12 V LUB EFR I4 to I4 IACC 12V EPS AERO 1 LRR 3% $1,25

4 2.4L I4 DVVL + CCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I4 IACC 42V EPS AERO 1 LRR 10% $2,055 2.0L I4 Turbo DCP + GDI dry DCT 6 spd 42 S-S LUB EFR I4 to I4 IACC 42V EPS AERO 1 LRR 10% $2,366 1.8L Turbo DCP + GDI lean burn DCT 6 spd 42 S-S LUB EFR I4 to I4 GDI-LB IACC 42V EPS AERO 1 LRR 30% $4,69

7 1.8L I4 Turbo HEV (IMA) + GDI dry DCT 6 spd HEV LUB EFR I4 to I4 AERO 1 LRR $4,628 1.8L I4 Turbo HEV (Power Split) + GDI N/A HEV LUB EFR I4 to I4 AERO 1 LRR $6,169 1.8L I4 Turbo HEV Plug-in IMA + GDI dry DCT 6 spd HEV LUB EFR I4 to I4 AERO 1 LRR $14,22

baseline 3.7L-2V SOHC V6 AT 4 spd 12V

1 3.7L 2V SOHC V6 AT 4 spd 12V LUB EFR ASL TORQ IACC 12V LRR $21

2 3.2L 2V SOHC V6 GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,04

3 3.2L 2V SOHC V6 w/Deac GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,19

4 2.8L 4V V6 GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,39

5 2.8L 4V V6 GDI + CCP + DVVL AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,69

6 2.8L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,66

7 2.8L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 SOHC to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR 10% $2,528 2.4L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 SOHC to I4 IACC 42V EPS AERO 1 LRR 10% $2,559 2.8L 4V V6 HCCI GDI DCT 6spd 42 S-S V6 SOHC to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR 30% $4,3810 2.4L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V6 SOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR 30% $4,8911 2.8L I4 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR 5% $2,96

12 3.0L 4V V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV V6 SOHC to V6 DOHC LUB EFR AERO 1 LRR $4,7113 3.0L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V6 SOHC to V6 DOHC LUB EFR AERO 1 LRR $5,94

Midsize/Large Car

V6 (T5)

Midsize Car/Large Car

V8 (T6)

Mid-sized MPV 

(unibody)/Small Truck

I4 (T7)

Midsize MPV (unibody)/Small Truck

V6/V8 (T8)
Technology Packages, Cost and Effectiv

1-15 

Table 1-11 Continued

baseline 4.0L-2V SOHC V6 AT 4 spd 12V

1 4.0L 2V SOHC V6 AT 4 spd 12V LUB EFR ASL TORQ IACC 12V LRR $21

2 3.6L 2V SOHC V6 GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,063 3.6L 2V SOHC V6 w/Deac GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,214 3.2L 4V V6 GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,415 3.2L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,696 3.2L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 SOHC to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR 10% $2,597 2.4L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 SOHC to I4 IACC 42V EPS AERO 1 LRR 10% $2,628 3.2L 4V V6 HCCI GDI DCT 6spd 42 S-S V6 SOHC to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR 30% $4,659 2.4L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V6 SOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR 30% $5,15

10 2.0L I4 Turbo HEV (IMA) + GDI DCT 6 spd HEV LUB EFR V6 SOHC to I4 AERO 1 LRR $4,8111 3.2L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V6 SOHC to V6 DOHC LUB EFR AERO 1 LRR $6,44baseline 4.7L-2V SOHC V8 AT 4 spd 12V

1 4.7L 2V SOHC V8 AT 4 spd 12V LUB EFR ASL TORQ IACC 12V LRR $21

2 4.4L 2V SOHC V8 GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,083 4.4L 2V SOHC V8 w/Deac GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,234 4.2L 4V V6 GDI + CCP AT 6 spd 12V LUB EFR V8 SOHC to V6 DOHC ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,285 4.2L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V LUB EFR V8 SOHC to V6 DOHC ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,576 4.2L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR V8 SOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 10% $2,51

7 2.8L 4V V6 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V8 SOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 10% $3,21

8 4.2L 4V V6 HCCI GDI DCT 6spd 42 S-S LUB EFR V8 SOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 30% $4,77

9 2.8L 4V V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V8 SOHC to V6 DOHC GDI-LB IACC 42V EPS AERO 1 LRR 30% $5,9510 3.0L V6 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR 5% $3,03

11 4.2L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR V8 SOHC to V6 DOHC AERO 1 LRR $6,29baseline 4.2L-2V SOHC V6 AT 4 spd 12V

1 4.2L 2V SOHC V6 AT 4 spd 12V LUB EFR ASL TORQ IACC 12V LRR $23

2 3.9L 2V SOHC V6 GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,103 3.9L 2V SOHC V6 w/Deac GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,274 3.6L 4V V6 GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,455 3.6L 4V V6 GDI + CCP + DVVL AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,846 3.6L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,757 3.6L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 SOHC to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR LDB 10% $2,738 2.5L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 SOHC to I4 IACC 42V EPS AERO 1 LRR LDB 10% $2,749 4.0L 4V V6 HCCI GDI DCT 6spd 42 S-S V6 SOHC to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR LDB 30% $4,9610 2.5L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V6 SOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR LDB 30% $5,18

11 2.8L I4 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR LDB 5% $3,87

12 3.6L 4V V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV V6 SOHC to V6 DOHC LUB EFR AERO 1 LRR LDB $5,8413 3.6L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V6 SOHC to V6 DOHC LUB EFR AERO 1 LRR LDB $8,36

baseline 3.8L 2V OHV V6 AT 4 sp 12 V1 3.8L-2V OHV V6 AT 4 spd 12V LUB EFR ASL TORQ IACC 12V LRR $232 3.2L 4V DOHC V6 GDI + CCP AT 6 spd 12V V6 OHV to V6 DOHC LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,323 3.2L 4V DOHC V6 w/Deac GDI + CCP AT 6 spd 12V V6 OHV to V6 DOHC LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,49

4 3.2L 4V DOHC V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 OHV to V6 DOHC LUB EFR IACC 42V EPS AERO 1 LRR LDB 10% $2,845 2.5L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 OHV to I4 DOHC IACC 42V EPS AERO 1 LRR LDB 10% $3,08

Large MPV (unibody)

V6 (T9)

Large MPV (unibody)

V8 (T10)

Large Truck (+ Van)

V6 (T11)

Large Truck + 

Large MPV V6 

(T12)
Draft Regulatory Impact Analysis 

1-16 

Table 1-11 Continued

baseline 5.7L 2V OHV V8 AT 4 spd 12V1 5.7L 2V OHV V8 AT 4 spd 12V LUB EFR ASL TORQ IACC 12V LRR $232 5.2L 2V OHV V8 GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,05

3 5.2L 2V OHV V8 w/Deac GDI + CCP AT 6 spd 12V LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,21

4 4.6L 4V V8 GDI + CCP AT 6 spd 12V V8 OHV to V8 DOHC LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,55

5 4.6L 4V V8 w/ Deac GDI + CCP AT 6 spd 12V V8 OHV to V8 DOHC LUB EFR ASL TORQ IACC 12V AERO 1 LRR 5% $1,87

6 4.6L 4V V8 w/ Deac GDI + CCP DCT 6 spd 42 S-S V8 SOHC to V8 DOHC LUB EFR IACC 42V EPS AERO 1 LRR LDB 10% $2,91

7 3.5L 4V V6 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V8 OHV to V6 DOHC IACC 42V EPS AERO 1 LRR LDB 10% $3,52

8 4.6L 4V V8 HCCI GDI DCT 6spd 42 S-S V8 OHV to V8 DOHC LUB EFR IACC 42V EPS AERO 1 LRR LDB 30% $5,64

9 3.5L V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V8 OHV to V6 DOHC GDI-LB IACC 42V EPS AERO 1 LRR LDB 30% $6,35

10 3.5L V6 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR AERO 1 LRR LDB 5% $3,84

11 4.6L 4V V8 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V8 OHV to V8 DOHC LUB EFR AERO 1 LRR LDB $8,51baseline 5.4L 3V SOHC V8 AT 4 sp 12 V1 5.4L 3V SOHC - V8 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $23

2 4.6L 4V DOHC V8 GDI + CCP AT 6 spd 12V V8 SOHC 3V to V8 DOH LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,21

3 4.6L 4V DOHC V8 w/ Deac GDI + CCP AT 6 spd 12V V8 SOHC 3V to V8 DOH LUB EFR ASL TORQ IACC 12V AERO 1 LRR 5% $1,534 4.6L 4V DOHC V8 w/ Deac GDI + CCP DCT 6 spd 42 S-S V8 SOHC 3V to V8 DOH LUB EFR IACC 42V EPS AERO 1 LRR LDB 10% $2,82

5 3.5L V6 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V8 SOHC 3V to V6 DOHC IACC 42V EPS AERO 1 LRR LDB 10% $3,29

baseline 3.2L-4V DOHC V6 AT 4 spd 12V1 3.2 L - 4V V6 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $21

2 2.8L V6 GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,04

3 2.8L V6 GDI + CCP + DVVL AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,34

4 2.8L V6 w/ Deac GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,31

5 2.8L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR 5% $1,886 2.4L I4 Turbo DCP + GDI DCT 6 spd 42 S-S LUB EFR V6 DOHC to I4 IACC 42V EPS AERO 1 LRR 5% $2,027 2.8L V6 HCCI GDI DCT 6spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR 30% $4,03

8 2.4L I4 Turbo DCP + GDI lean burn DCT 6 spd 42 S-S LUB EFR V6 DOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR 30% $4,49

9 2.8L I4 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR 5% $2,96

10 3.0L V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV LUB EFR AERO 1 LRR $4,3511 3.0L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR AERO 1 LRR $5,58

baseline 3.5L-4V DOHC V6 AT 4 spd 12V1 3.5L - 4V V6 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $21

2 3.2L V6 GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,06

3 3.2L V6 w/ Deac GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,34

4 3.2L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR 10% $2,24

5 2.4L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 DOHC to I4 IACC 42V EPS AERO 1 LRR 5% $2,056 3.2L V6 HCCI GDI DCT 6spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR 30% $4,30

7 2.4L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V6 DOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR 30% $4,91

8 2.0L I4 Turbo HEV (IMA) + GDI DCT 6 spd HEV LUB EFR V6 DOHC to I4 AERO 1 LRR $4,53

9 3.2L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR AERO 1 LRR $6,09

Large Truck (+ Van)

V8 (T13)

Large Truck 

(+Van) V8 (T14)

Midsize MPV (unibody)/Small 

Truck

V6/V8 (T15)

Large MPV (unibody)

V6 (T16)
Technology Packages, Cost and Effectiv

1-17 

Table 1-11 Continued

baseline 4.6L-4V DOHC V8 AT 4 spd 12V1 4.6L - 4V V8 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $21

2 4.2L V6 GDI + CCP AT 8 spd 12 V LUB EFR V8 DOHC to V6 DOHC ASL TORQ IACC 12V EPS AERO 1 LRR 3% $923 4.2L V6 w/ Deac GDI + CCP AT 8 spd 12 V LUB EFR V8 DOHC to V6 DOHC ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,224 4.2L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 10% $2,155 2.8L V6 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 10% $2,85

6 4.2L V6 HCCI GDI DCT 6spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR 30% $4,41

7 2.8L V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V8 DOHC to V6 DOHC GDI-LB IACC 42V EPS AERO 1 LRR 30% $5,598 3.0L V6 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR 5% $3,03

9 4.2L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR V8 DOHC to V6 DOHC AERO 1 LRR $5,93

baseline 4.0L-4V DOHC V6 AT 4 spd 12V1 4.0L - 4V V6 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $23

2 3.6L V6 GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 3% $1,10

3 3.6L V6 GDI + CCP + DVVL AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,484 3.6L V6 w/ Deac GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V EPS AERO 1 LRR 5% $1,39

5 3.6L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR LDB 10% $2,38

6 2.5L I4 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V6 DOHC to I4 IACC 42V EPS AERO 1 LRR LDB 10% $2,507 4.0L V6 HCCI GDI DCT 6spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR LDB 30% $4,61

8 2.5L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V6 DOHC to I4 GDI-LB IACC 42V EPS AERO 1 LRR LDB 30% $4,94

9 2.8L I4 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR EPS AERO 1 LRR LDB 5% $3,87

10 3.6L V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV LUB EFR AERO 1 LRR LDB $5,4911 3.6L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR AERO 1 LRR LDB $8,01

baseline 5.6L 4V DOHC V8 AT 4 spd 12V

1 5.6L 4V V8 AT 4 spd 12 V LUB EFR ASL TORQ IACC 12V LRR $23

2 4.6L V8 GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V AERO 1 LRR 3% $1,05

3 4.6L V8 w/ Deac GDI + CCP AT 6 spd 12 V LUB EFR ASL TORQ IACC 12V AERO 1 LRR 5% $1,37

4 4.6L V8 w/ Deac GDI + CCP DCT 6 spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR LDB 10% $2,515 3.5L V6 Turbo DCP + GDI DCT 6spd 42 S-S LUB EFR V8 DOHC to V6 DOHC IACC 42V EPS AERO 1 LRR LDB 10% $3,03

6 4.6L V8 HCCI GDI DCT 6spd 42 S-S LUB EFR IACC 42V EPS AERO 1 LRR LDB 30% $5,13

7 3.5L V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S LUB EFR V8 DOHC to V6 DOHC GDI-LB IACC 42V EPS AERO 1 LRR LDB 30% $5,878 3.5L V6 Turbo Diesel DCT 6 spd 12 LUB EFR Diesel-SCR AERO 1 LRR LDB 5% $3,84

9 4.6L V8 w/ Deac GDI + CCP HEV (2-mode) N/A HEV LUB EFR AERO 1 LRR LDB $8,01

Large MPV (unibody)

V8 (T17)

Large Truck (+ Van)

V6 (T18)

Large Truck (+ Van)

V8 (T19)

Notes to Table 1-11: DOHC=dual overhead cam; SOHC=single overhead cam; OHV=overhead valve; AT=automatic transmission; DCT=dual clutch transmission; LUB=low friction lubes; EFR=engine fr

reduction; ASL=aggressive shift logic; TORQ=early torque converter lockup; IACC=improved accessories; EPS=electric power steering; AERO 1=improved aerodynamics; LRR=low resistance tires. 
Draft Regulatory Impact Analysis 

1-18 

Table 1-12 Package Costs & Effectiveness for 2012-2022+MY for 19 Vehicle Types (T1-T19), Packages Used as Inputs to the OMEGA Model, Costs in 2007 dollars 

Vehicle

Technology

Package Engine Transmission

System 

Voltage

Camshaft changes

(excluding those for downsized engines) 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 CO2 % Reduction

baseline 1.5L - 4V DOHC I4 AT 4 spd 12 V1 1.5L - 4V I4 AT 4 spd 12 V $206 $202 $197 $193 $189 $189 $189 $189 $189 $189 $182 7.6%2 1.5L - 4V I4 CCP DCT 6 spd 12 V $801 $779 $757 $736 $716 $716 $716 $716 $716 $716 $685 18.9%

3 1.2L I3 DVVL + CCP + GDI dry DCT 6 spd 42 S-S $1,751 $1,717 $1,574 $1,454 $1,422 $1,422 $1,422 $1,422 $1,422 $1,422 $1,340 33.2%

4 0.7L I3 (small) Turbo DCP + GDI dry DCT 6 spd 42 S-S $2,343 $2,291 $2,130 $1,994 $1,946 $1,946 $1,946 $1,946 $1,946 $1,946 $1,820 36.4%5 150kW/lithium ion (range of FTP 150 miles) N/A HEV

baseline 2.4L-4V DOHC I4 AT 4 spd 12 V1 2.4L 4V I4 AT 4 spd 12 V $206 $202 $197 $193 $189 $189 $189 $189 $189 $189 $182 7.6%

2 2.0L I4 CCP + GDI AT 6 spd 12 V $911 $886 $861 $837 $814 $814 $814 $814 $814 $814 $784 17.5%3 2.4L -4V I4 CCP + GDI DCT 6 spd 12 V

4 2.0L I4 DVVL + CCP + GDI dry DCT 6 spd 42 S-S $2,037 $1,994 $1,843 $1,715 $1,675 $1,675 $1,675 $1,675 $1,675 $1,675 $1,593 35.4%

5 1.5L I4 Turbo DCP + GDI dry DCT 6 spd 42 S-S

6 1.2L I4 HEV (IMA) + GDI dry DCT 6 spd HEV7 1.2L I4 HEV Plug-in IMA + GDI dry DCT 6 spd HEVbaseline 2.4L-4V DOHC I4 AT 4 spd 12 V

1 2.4L - 4V I4 AT 4 spd 12 V $206 $202 $197 $193 $189 $189 $189 $189 $189 $189 $182 7.6%2 2.2L I4 CCP + GDI AT 6 spd 12 V

3 2.2L I4 DVVL + CCP + GDI DCT 6 spd 12 V $1,137 $1,105 $1,074 $1,043 $1,014 $1,014 $1,014 $1,014 $1,014 $1,014 $972 23.2%4 2.2L I4 DVVL + CCP + GDI dry DCT 6 spd 42 S-S $2,108 $2,063 $1,910 $1,780 $1,739 $1,739 $1,739 $1,739 $1,739 $1,739 $1,656 35.4%5 1.6L I4 Turbo DCP + GDI dry DCT 6 spd 42 S-S

6 1.6L Turbo DCP + GDI lean burn dry DCT 6 spd 42 S-S7 1.4L I4 Turbo HEV (IMA) + GDI dry DCT 6 spd HEV8 1.8L I4 HEV (Power Split) + GDI N/A HEV $4,785 $4,644 $4,506 $4,373 $4,243 $4,243 $4,243 $4,243 $4,243 $4,243 $3,710 35.9%

9 1.8L I4 HEV Plug-in Power Split + GDI N/A HEVbaseline 3.0L-4V DOHC V6 AT 4 spd 12 V

1 3.0L - 4V V6 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%

2 2.0L I4 Turbo DCP + GDI AT 6 spd 12 V

3 2.0L I4 Turbo DCP + GDI DCT 6 spd 12 V $1,562 $1,518 $1,475 $1,433 $1,392 $1,392 $1,392 $1,392 $1,392 $1,392 $1,190 23.4%4 2.0L I4 Turbo DCP + GDI DCT 6 spd 42 S-S $2,392 $2,341 $2,168 $2,021 $1,974 $1,974 $1,974 $1,974 $1,974 $1,974 $1,725 31.6%5 2.0L Turbo DCP + GDI lean burn DCT 6 spd 42 S-S

6 2.4L I4 Turbo Diesel DCT 6 spd

7 1.5L I4 Turbo HEV (IMA) + GDI DCT 6 spd HEV

8 2.8L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV $9,234 $9,215 $7,493 $6,112 $6,095 $6,095 $6,095 $6,095 $6,095 $6,095 $5,310 36.5%

Subcomp

I4 (T1)

Compact Car 

I4 (T2)

Midsize Car/Small MPV 

(unibody)

I4 (T3)

Compact Car/Small 

MPV (unibody)

V6 (T4)
Technology Packages, Cost and Effectiv

1-19 

Table 1-12 Continued

baseline 3.3L-4V DOHC V6 AT 4 spd 12 V1 3.3L - 4V V6 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%

2 3.0L V6 GDI + CCP AT 6 spd 12 V $1,144 $1,112 $1,081 $1,051 $1,022 $1,022 $1,022 $1,022 $1,022 $1,022 $927 17.9%

3 3.0L V6 w/ Deac GDI + CCP AT 6 spd 12 V

4 3.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S $2,537 $2,482 $2,305 $2,153 $2,103 $2,103 $2,103 $2,103 $2,103 $2,103 $1,942 34.2%5 2.2L I4 Turbo DCP + GDI DCT 6spd 42 S-S

6 3.0L V6 HCCI GDI DCT 6spd 42 S-S7 2.2L Turbo DCP + GDI lean burn DCT 6spd 42 S-S8 2.5L I4 HEV (Power Split) + GDI N/A HEV $6,772 $6,572 $6,377 $6,188 $6,005 $6,005 $6,005 $6,005 $6,005 $6,005 $5,129 37.5%

baseline 4.5L-4V DOHC V8 AT 4 spd 12 V1 4.5L - 4V V8 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%

2 4.0L V6 GDI + CCP AT 6 spd 12 V $986 $959 $933 $907 $883 $883 $883 $883 $883 $883 $780 17.9%

3 4.0L V6 w/ Deac GDI + CCP AT 6 spd 42 S-S4 4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S $2,103 $2,061 $1,896 $1,757 $1,719 $1,719 $1,719 $1,719 $1,719 $1,719 $1,552 31.9%5 3.0L V6 Turbo DCP + GDI AT 6 spd 42 S-S6 3.0L V6 Turbo DCP + GDI DCT 6 spd 42 S-S7 4.0L V6 HCCI GDI DCT 6 spd 42 S-S8 3.0L V6 Turbo Diesel DCT 6 spd 129 3.0L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV $9,082 $9,068 $7,346 $5,966 $5,953 $5,953 $5,953 $5,953 $5,953 $5,953 $5,143 44.4%baseline 2.6L-4V DOHC I4 (I5) AT 4 spd 12 V1 2.6 L - 4V I4 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%2 2.4L I4 CCP + GDI AT 6 spd 12 V $1,104 $1,074 $1,044 $1,015 $987 $987 $987 $987 $987 $987 $890 17.4%3 2.4L I4 DVVL + CCP + GDI DCT 6 spd 12 V $1,406 $1,367 $1,328 $1,291 $1,255 $1,255 $1,255 $1,255 $1,255 $1,255 $1,139 21.4%4 2.4L I4 DVVL + CCP + GDI dry DCT 6 spd 42 S-S $2,481 $2,428 $2,252 $2,102 $2,054 $2,054 $2,054 $2,054 $2,054 $2,054 $1,896 34.7%5 2.0L I4 Turbo DCP + GDI dry DCT 6 spd 42 S-S $2,837 $2,773 $2,587 $2,427 $2,369 $2,369 $2,369 $2,369 $2,369 $2,369 $2,172 36.3%6 1.8L Turbo DCP + GDI lean burn DCT 6 spd 42 S-S7 1.8L I4 Turbo HEV (IMA) + GDI dry DCT 6 spd HEV

8 1.8L I4 Turbo HEV (Power Split) + GDI N/A HEV $6,951 $6,745 $6,545 $6,352 $6,164 $6,164 $6,164 $6,164 $6,164 $6,164 $5,335 39.6%

9 1.8L I4 Turbo HEV Plug-in IMA + GDI dry DCT 6 spd HEVbaseline 3.7L-2V SOHC V6 AT 4 spd 12V1 3.7L 2V SOHC V6 AT 4 spd 12V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%

2 3.2L 2V SOHC V6 GDI + CCP AT 6 spd 12V $1,168 $1,136 $1,104 $1,073 $1,044 $1,044 $1,044 $1,044 $1,044 $1,044 $948 17.8%

3 3.2L 2V SOHC V6 w/Deac GDI + CCP AT 6 spd 12V $1,337 $1,300 $1,263 $1,228 $1,194 $1,194 $1,194 $1,194 $1,194 $1,194 $1,093 19.6%

4 2.8L 4V V6 GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC

5 2.8L 4V V6 GDI + CCP + DVVL AT 6 spd 12V V6 SOHC to V6 DOHC

6 2.8L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC

7 2.8L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 SOHC to V6 DOHC $3,017 $2,948 $2,756 $2,591 $2,528 $2,528 $2,528 $2,528 $2,528 $2,528 $2,354 32.4%

8 2.4L I4 Turbo DCP + GDI DCT 6spd 42 S-S

9 2.8L 4V V6 HCCI GDI DCT 6spd 42 S-S V6 SOHC to V6 DOHC10 2.4L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S11 2.8L I4 Turbo Diesel DCT 6 spd 1212 3.0L 4V V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV V6 SOHC to V6 DOHC13 3.0L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V6 SOHC to V6 DOHC $8,838 $8,807 $7,233 $5,968 $5,940 $5,940 $5,940 $5,940 $5,940 $5,940 $5,193 36.3%

Midsize/Large Car

V6 (T5)

Midsize Car/Large Car

V8 (T6)

Mid-sized MPV 

(unibody)/Small Truck

I4 (T7)

Midsize MPV (unibody)/Small Truck

V6/V8 (T8)
Draft Regulatory Impact Analysis 

1-20 

Table 1-12 Continued 

baseline 4.0L-2V SOHC V6 AT 4 spd 12V1 4.0L 2V SOHC V6 AT 4 spd 12V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%

2 3.6L 2V SOHC V6 GDI + CCP AT 6 spd 12V $1,191 $1,158 $1,126 $1,095 $1,064 $1,064 $1,064 $1,064 $1,064 $1,064 $969 17.4%

3 3.6L 2V SOHC V6 w/Deac GDI + CCP AT 6 spd 12V $1,360 $1,322 $1,285 $1,249 $1,214 $1,214 $1,214 $1,214 $1,214 $1,214 $1,113 19.4%4 3.2L 4V V6 GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC

5 3.2L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC

6 3.2L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 SOHC to V6 DOHC7 2.4L I4 Turbo DCP + GDI DCT 6spd 42 S-S $3,125 $3,052 $2,857 $2,690 $2,623 $2,623 $2,623 $2,623 $2,623 $2,623 $2,409 32.3%

8 3.2L 4V V6 HCCI GDI DCT 6spd 42 S-S V6 SOHC to V6 DOHC9 2.4L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S

10 2.0L I4 Turbo HEV (IMA) + GDI DCT 6 spd HEV11 3.2L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V6 SOHC to V6 DOHC $9,633 $9,602 $7,869 $6,477 $6,449 $6,449 $6,449 $6,449 $6,449 $6,449 $5,651 36.5%

baseline 4.7L-2V SOHC V8 AT 4 spd 12V1 4.7L 2V SOHC V8 AT 4 spd 12V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%

2 4.4L 2V SOHC V8 GDI + CCP AT 6 spd 12V $1,215 $1,181 $1,148 $1,116 $1,085 $1,085 $1,085 $1,085 $1,085 $1,085 $990 17.4%

3 4.4L 2V SOHC V8 w/Deac GDI + CCP AT 6 spd 12V $1,384 $1,345 $1,307 $1,271 $1,235 $1,235 $1,235 $1,235 $1,235 $1,235 $1,134 19.4%4 4.2L 4V V6 GDI + CCP AT 6 spd 12V

5 4.2L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V

6 4.2L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S $2,999 $2,930 $2,739 $2,575 $2,512 $2,512 $2,512 $2,512 $2,512 $2,512 $2,342 34.3%

7 2.8L 4V V6 Turbo DCP + GDI DCT 6spd 42 S-S8 4.2L 4V V6 HCCI GDI DCT 6spd 42 S-S9 2.8L 4V V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S10 3.0L V6 Turbo Diesel DCT 6 spd 12

11 4.2L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV $9,458 $9,433 $7,704 $6,317 $6,294 $6,294 $6,294 $6,294 $6,294 $6,294 $5,486 36.5%

baseline 4.2L-2V SOHC V6 AT 4 spd 12V1 4.2L 2V SOHC V6 AT 4 spd 12V $256 $252 $247 $243 $239 $239 $239 $239 $239 $239 $231 7.6%

2 3.9L 2V SOHC V6 GDI + CCP AT 6 spd 12V $1,233 $1,199 $1,167 $1,135 $1,104 $1,104 $1,104 $1,104 $1,104 $1,104 $984 18.3%

3 3.9L 2V SOHC V6 w/Deac GDI + CCP AT 6 spd 12V $1,424 $1,384 $1,346 $1,309 $1,273 $1,273 $1,273 $1,273 $1,273 $1,273 $1,146 19.9%4 3.6L 4V V6 GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC

5 3.6L 4V V6 GDI + CCP + DVVL AT 6 spd 12V V6 SOHC to V6 DOHC

6 3.6L 4V V6 w/ Deac GDI + CCP AT 6 spd 12V V6 SOHC to V6 DOHC

7 3.6L 4V V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 SOHC to V6 DOHC $3,256 $3,184 $2,977 $2,800 $2,735 $2,735 $2,735 $2,735 $2,735 $2,735 $2,529 34.9%

8 2.5L I4 Turbo DCP + GDI DCT 6spd 42 S-S9 4.0L 4V V6 HCCI GDI DCT 6spd 42 S-S V6 SOHC to V6 DOHC

10 2.5L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S11 2.8L I4 Turbo Diesel DCT 6 spd 1212 3.6L 4V V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV V6 SOHC to V6 DOHC13 3.6L 4V V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V6 SOHC to V6 DOHCbaseline 3.8L 2V OHV V6 AT 4 sp 12 V1 3.8L-2V OHV V6 AT 4 spd 12V $256 $252 $247 $243 $239 $239 $239 $239 $239 $239 $231 7.6%

2 3.2L 4V DOHC V6 GDI + CCP AT 6 spd 12V V6 OHV to V6 DOHC $1,482 $1,441 $1,401 $1,362 $1,324 $1,324 $1,324 $1,324 $1,324 $1,324 $1,196 18.9%

3 3.2L 4V DOHC V6 w/Deac GDI + CCP AT 6 spd 12V V6 OHV to V6 DOHC $1,672 $1,625 $1,580 $1,536 $1,493 $1,493 $1,493 $1,493 $1,493 $1,493 $1,358 20.1%4 3.2L 4V DOHC V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S V6 OHV to V6 DOHC $3,381 $3,305 $3,095 $2,914 $2,845 $2,845 $2,845 $2,845 $2,845 $2,845 $2,635 34.9%

5 2.5L I4 Turbo DCP + GDI DCT 6spd 42 S-S $3,653 $3,569 $3,351 $3,163 $3,087 $3,087 $3,087 $3,087 $3,087 $3,087 $2,820 35.1%

Large MPV (unibody)

V6 (T9)

Large MPV (unibody)

V8 (T10)

Large Truck (+ Van)

V6 (T11)

Large Truck + 

Large MPV V6 

(T12)
Technology Packages, Cost and Effectiv

1-21 

Table 1-12 Continued

baseline 5.7L 2V OHV V8 AT 4 spd 12V

1 5.7L 2V OHV V8 AT 4 spd 12V $256 $252 $247 $243 $239 $239 $239 $239 $239 $239 $231 7.6%

2 5.2L 2V OHV V8 GDI + CCP AT 6 spd 12V $1,172 $1,141 $1,110 $1,080 $1,051 $1,051 $1,051 $1,051 $1,051 $1,051 $933 18.3%

3 5.2L 2V OHV V8 w/Deac GDI + CCP AT 6 spd 12V $1,363 $1,325 $1,289 $1,253 $1,219 $1,219 $1,219 $1,219 $1,219 $1,219 $1,096 19.9%

4 4.6L 4V V8 GDI + CCP AT 6 spd 12V V8 OHV to V8 DOHC5 4.6L 4V V8 w/ Deac GDI + CCP AT 6 spd 12V V8 OHV to V8 DOHC6 4.6L 4V V8 w/ Deac GDI + CCP DCT 6 spd 42 S-S V8 SOHC to V8 DOHC $3,457 $3,379 $3,167 $2,984 $2,913 $2,913 $2,913 $2,913 $2,913 $2,913 $2,705 34.9%

7 3.5L 4V V6 Turbo DCP + GDI DCT 6spd 42 S-S $4,142 $4,044 $3,812 $3,610 $3,520 $3,520 $3,520 $3,520 $3,520 $3,520 $3,223 35.1%

8 4.6L 4V V8 HCCI GDI DCT 6spd 42 S-S V8 OHV to V8 DOHC

9 3.5L V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S

10 3.5L V6 Turbo Diesel DCT 6 spd 1211 4.6L 4V V8 w/ Deac GDI + CCP HEV (2-mode) N/A HEV V8 OHV to V8 DOHC

baseline 5.4L 3V SOHC V8 AT 4 sp 12 V1 5.4L 3V SOHC - V8 AT 4 spd 12 V $256 $252 $247 $243 $239 $239 $239 $239 $239 $239 $239 7.6%2 4.6L 4V DOHC V8 GDI + CCP AT 6 spd 12V V8 SOHC 3V to V8 DOHC $1,352 $1,315 $1,279 $1,244 $1,210 $1,210 $1,210 $1,210 $1,210 $1,210 $1,161 18.9%

3 4.6L 4V DOHC V8 w/ Deac GDI + CCP AT 6 spd 12V V8 SOHC 3V to V8 DOHC $1,714 $1,666 $1,619 $1,574 $1,530 $1,530 $1,530 $1,530 $1,530 $1,530 $1,456 21.2%

4 4.6L 4V DOHC V8 w/ Deac GDI + CCP DCT 6 spd 42 S-S V8 SOHC 3V to V8 DOHC $3,357 $3,282 $3,073 $2,893 $2,825 $2,825 $2,825 $2,825 $2,825 $2,825 $2,687 34.9%

5 3.5L V6 Turbo DCP + GDI DCT 6spd 42 S-S $3,889 $3,798 $3,573 $3,379 $3,295 $3,295 $3,295 $3,295 $3,295 $3,295 $3,085 35.1%

baseline 3.2L-4V DOHC V6 AT 4 spd 12V

1 3.2 L - 4V V6 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%2 2.8L V6 GDI + CCP AT 6 spd 12 V $1,168 $1,136 $1,104 $1,073 $1,044 $1,044 $1,044 $1,044 $1,044 $1,044 $948 17.8%

3 2.8L V6 GDI + CCP + DVVL AT 6 spd 12 V4 2.8L V6 w/ Deac GDI + CCP AT 6 spd 12 V5 2.8L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S $2,286 $2,239 $2,068 $1,924 $1,881 $1,881 $1,881 $1,881 $1,881 $1,881 $1,722 31.8%6 2.4L I4 Turbo DCP + GDI DCT 6 spd 42 S-S

7 2.8L V6 HCCI GDI DCT 6spd 42 S-S

8 2.4L I4 Turbo DCP + GDI lean burn DCT 6 spd 42 S-S

9 2.8L I4 Turbo Diesel DCT 6 spd 12 $3,342 $3,244 $3,149 $3,057 $2,968 $2,968 $2,968 $2,968 $2,968 $2,968 $2,732 32.6%

10 3.0L V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV11 3.0L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV $8,439 $8,420 $6,857 $5,603 $5,586 $5,586 $5,586 $5,586 $5,586 $5,586 $4,852 35.8%baseline 3.5L-4V DOHC V6 AT 4 spd 12V

1 3.5L - 4V V6 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%2 3.2L V6 GDI + CCP AT 6 spd 12 V $1,191 $1,158 $1,126 $1,095 $1,064 $1,064 $1,064 $1,064 $1,064 $1,064 $969 17.4%

3 3.2L V6 w/ Deac GDI + CCP AT 6 spd 12 V4 3.2L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S

5 2.4L I4 Turbo DCP + GDI DCT 6spd 42 S-S $2,485 $2,431 $2,255 $2,105 $2,057 $2,057 $2,057 $2,057 $2,057 $2,057 $1,806 31.6%

6 3.2L V6 HCCI GDI DCT 6spd 42 S-S

7 2.4L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S

8 2.0L I4 Turbo HEV (IMA) + GDI DCT 6 spd HEV

9 3.2L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV $9,234 $9,215 $7,493 $6,112 $6,095 $6,095 $6,095 $6,095 $6,095 $6,095 $5,310 36.5%

Large Truck (+ Van)

V8 (T13)

Large Truck 

(+Van) V8 (T14)

Midsize MPV (unibody)/Small 

Truck

V6/V8 (T15)

Large MPV (unibody)

V6 (T16)
Draft Regulatory Impact Analysis 

1-22 

Table 1-12 Continued

baseline 4.6L-4V DOHC V8 AT 4 spd 12V

1 4.6L - 4V V8 AT 4 spd 12 V $231 $227 $222 $218 $214 $214 $214 $214 $214 $214 $207 7.6%2 4.2L V6 GDI + CCP AT 8 spd 12 V $1,035 $1,006 $979 $952 $926 $926 $926 $926 $926 $926 $823 17.4%

3 4.2L V6 w/ Deac GDI + CCP AT 8 spd 12 V $1,368 $1,329 $1,292 $1,256 $1,221 $1,221 $1,221 $1,221 $1,221 $1,221 $1,111 20.5%4 4.2L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S $2,593 $2,537 $2,358 $2,205 $2,153 $2,153 $2,153 $2,153 $2,153 $2,153 $1,984 33.7%5 2.8L V6 Turbo DCP + GDI DCT 6spd 42 S-S

6 4.2L V6 HCCI GDI DCT 6spd 42 S-S

7 2.8L V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S

8 3.0L V6 Turbo Diesel DCT 6 spd 129 4.2L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEV $9,053 $9,040 $7,323 $5,948 $5,935 $5,935 $5,935 $5,935 $5,935 $5,935 $5,127 36.5%

baseline 4.0L-4V DOHC V6 AT 4 spd 12V

1 4.0L - 4V V6 AT 4 spd 12 V $256 $252 $247 $243 $239 $239 $239 $239 $239 $239 $231 7.6%2 3.6L V6 GDI + CCP AT 6 spd 12 V $1,233 $1,199 $1,167 $1,135 $1,104 $1,104 $1,104 $1,104 $1,104 $1,104 $984 18.3%

3 3.6L V6 GDI + CCP + DVVL AT 6 spd 12 V4 3.6L V6 w/ Deac GDI + CCP AT 6 spd 12 V $1,565 $1,521 $1,479 $1,437 $1,398 $1,398 $1,398 $1,398 $1,398 $1,398 $1,270 21.0%5 3.6L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S $2,856 $2,796 $2,601 $2,436 $2,381 $2,381 $2,381 $2,381 $2,381 $2,381 $2,187 34.4%6 2.5L I4 Turbo DCP + GDI DCT 6spd 42 S-S $2,995 $2,931 $2,732 $2,562 $2,504 $2,504 $2,504 $2,504 $2,504 $2,504 $2,220 34.5%

7 4.0L V6 HCCI GDI DCT 6spd 42 S-S

8 2.5L I4 Turbo DCP + GDI lean burn DCT 6spd 42 S-S

9 2.8L I4 Turbo Diesel DCT 6 spd 12

10 3.6L V6 w/ Deac GDI + CCP HEV (IMA) DCT 6 spd HEV11 3.6L V6 w/ Deac GDI + CCP HEV (2-mode) N/A HEVbaseline 5.6L 4V DOHC V8 AT 4 spd 12V

1 5.6L 4V V8 AT 4 spd 12 V $256 $252 $247 $243 $239 $239 $239 $239 $239 $239 $231 7.6%2 4.6L V8 GDI + CCP AT 6 spd 12 V $1,172 $1,141 $1,110 $1,080 $1,051 $1,051 $1,051 $1,051 $1,051 $1,051 $933 18.3%3 4.6L V8 w/ Deac GDI + CCP AT 6 spd 12 V $1,363 $1,325 $1,289 $1,253 $1,219 $1,219 $1,219 $1,219 $1,219 $1,219 $1,096 21.0%4 4.6L V8 w/ Deac GDI + CCP DCT 6 spd 42 S-S $1,556 $1,515 $1,475 $1,435 $1,398 $1,398 $1,398 $1,398 $1,398 $1,398 $1,272 34.4%5 3.5L V6 Turbo DCP + GDI DCT 6spd 42 S-S $2,145 $2,086 $2,029 $1,973 $1,919 $1,919 $1,919 $1,919 $1,919 $1,919 $1,703 34.5%

6 4.6L V8 HCCI GDI DCT 6spd 42 S-S

7 3.5L V6 Turbo DCP + GDI lean burn DCT 6spd 42 S-S

8 3.5L V6 Turbo Diesel DCT 6 spd 129 4.6L V8 w/ Deac GDI + CCP HEV (2-mode) N/A HEV

Large MPV (unibody)

V8 (T17)

Large Truck (+ Van)

V6 (T18)

Large Truck (+ Van)

V8 (T19)
Technology Packages, Cost and Effectiveness 

1-23 

Table 1-13 Package Costs Measured Relative to the Package Costs for the 2016MY 

YEAR PACKAGE COSTS 

RELATIVE TO 2016

2012 117% 

2013 115% 

2014 108% 

2015 102% 

2016 100% 

2017 100% 

2018 100% 

2019 100% 

2020 100% 

2021 100% 

2022+ 92% 

We do not show cost and effectiveness estimates for a number of the technology listed 

in Table 1-12, as we determined that these packages were not cost effective relative to other 

packages available for a specific vehicle type. The process used to make these determinations 

is discussed below. 

As discussed in detail in Chapter 4 of this DRIA, the order of technology which will 

be applied to any specific vehicle by the OMEGA model is set in the Technology input file. 

Since the goal of adding technology is to move the manufacturer closer to compliance with 

the GHG standard, the available technology packages should be placed in order of their total 

GHG effectiveness. Otherwise, the model is adding technology which moves the 

manufacturer further from compliance. At the same time, the cost of each successive package 

should be greater than that of the prior package. In this case, a greater degree of GHG 

reduction is available at a lower cost. The package with the greater cost and lower overall 

effectiveness should therefore be removed from the list. 

Table 1-14 presents the complete list of technology packages which were described 

for vehicle type #6, which includes midsize and large cars equipped with a V8 engine with 

either SOHC or DOHC and 4 valves per head. The only exception is that the package 

including an HCCI engine has been removed as this technology is not expected to be 

commercially available in time for widespread introduction by 2016. The information listed 

in the first six columns is taken from Table 1-12. The values in the seventh column, which 

are explained below, are used to remove packages which would not likely be applied by a 

manufacturer and therefore, should not be included in the OMEGA modeling. 
Draft Regulatory Impact Analysis 

1-24 

Table 1-14 Evaluation of Technology Packages for Vehicle Type #6 

Engine Transmission 

System 

Voltage 

Weight 

Reduction 

Total CO2

Reduction 

Total 2016 

Cost 

$/delta CO2

% 

4.5L DOHC 4-Valve V8 AT 4 spd 12V 0% 7.6% $214 $2,816 

4.0L V6 GDI + CCP AT 6 spd 12V 3% 17.9% $883 $6,497 

4.0L V6 w/ Deac GDI + CCP AT 6 spd 42 S-S 5% 28.2% $1633 $7,274 

3.0L V6 Turbo DCP + GDI AT 6 spd 42 S-S 5% 28.5% $2333 $284,727 

4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S 5% 31.9% $1719 $(17,617) 

3.0L V6 Turbo DCP + GDI DCT 6spd 42 S-S 5% 32.1% $2419 $2,363 

3.0L V6 Turbo Diesel DCT 6 spd 12V 5% 35.0% $3456 $35,737 

3.0L V6 w/ Deac GDI+CCP HEV 2-mode HEV 0% 44.4% $5953 $26,586 

Remove Turbo with AT 6 spd 

4.5L DOHC 4-Valve V8 AT 4 spd 12V 0% 7.6% $214 $2,816 

4.0L V6 GDI + CCP AT 6 spd 12V 3% 17.9% $883 $6,497 

4.0L V6 w/ Deac GDI + CCP AT 6 spd 42 S-S 5% 28.2% $1633 $7,274 

4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S 5% 31.9% $1719 $2,305 

3.0L V6 Turbo DCP + GDI DCT 6spd 42 S-S 5% 32.1% $2419 $452,082 

3.0L V6 Turbo Diesel DCT 6 spd 12V 5% 35.0% $3456 $35,737 

3.0L V6 w/ Deac GDI + CCP HEV 2-mode HEV 0% 44.4% $5953 $26,586 

Remove Turbo with DCT 6 spd 

4.5L DOHC 4-Valve V8 AT 4 spd 12V 0% 7.6% $214 $2,816 

4.0L V6 GDI + CCP AT 6 spd 12V 3% 17.9% $883 $6,497 

4.0L V6 w/ Deac GDI + CCP AT 6 spd 42 S-S 5% 28.2% $1633 $7,274 

4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S 5% 31.9% $1719 $2,305 

3.0L V6 Turbo Diesel DCT 6 spd 12V 5% 35.0% $3456 $56,828 

3.0L V6 w/ Deac GDI + CCP HEV 2-mode HEV 0% 44.4% $5953 $26,586 

Remove Diesel 

4.5L DOHC 4-Valve V8 AT 4 spd 12V 0% 7.6% $214 $2,816 

4.0L V6 GDI + CCP AT 6 spd 12V 3% 17.9% $883 $6,497 

4.0L V6 w/ Deac GDI + CCP AT 6 spd 42 S-S 5% 28.2% $1633 $7,274 

4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S 5% 31.9% $1719 $2,305 

3.0L V6 w/ Deac GDI + CCP HEV 2-mode HEV 0% 44.4% $5953 $34,012 

Remove two AT 6 spd steps 

4.5L DOHC 4-Valve V8 AT 4 spd 12V 0% 7.6% $214 $2,816 

4.0L V6 w/ Deac GDI + CCP DCT 6 spd 42 S-S 5% 31.9% $1719 $6,184 

3.0L V6 w/ Deac GDI + CCP HEV 2-mode HEV 0% 44.4% $5953 $34,012 

The seventh, or last column of Table 1-14 is a measure of the incremental cost 

effectiveness of each package relative to the previous package. Specifically, it is the ratio of 

the incremental cost of the current package over the previous package to the incremental 

effectiveness of the current package over the previous package. In both cases (cost and 

effectiveness), the increment is the arithmetic difference. As discussed above, OMEGA uses 

a different measure of incremental effectiveness in its calculation of CO2 emissions. Here, 

however, the arithmetic difference in the effectiveness of two technology packages provides 

the best comparison across packages, since the base CO2 emissions inherent in the total 

effectiveness estimates is the same; that of the base vehicle. Therefore, a 10% difference 

between two packages with 7% and 17% effectiveness, respectively, represents the same CO2

emission reduction as a 10% difference between two packages with 27% and 37% 
Technology Packages, Cost and Effectiveness 

1-25 

effectiveness, respectively. Generally, a low ratio of incremental cost to incremental 

effectiveness is better than a high ratio. Ideally, the technology packages included in the 

model would progress from lower ratios to higher ratios. 

The topmost section of Table 1-14 shows all of the packages described earlier except 

for the HCCI engine package. The order of the packages has been rearranged slightly from 

that in Table 1-12 in order to place the packages in order of increasing total effectiveness. As 

can be seen, there are two very large anomalies in the ratios of incremental cost to incremental 

effectiveness. The ratio for the turbocharged engine with a 6 speed automatic transmission is 

very high, while that for the engine with cylinder deactivation with a dual clutch transmission 

is negative. The cause of this is that the cost of the latter package is lower than the former. If 

the latter package can achieve a 31.9% reduction in CO2 emissions at a cost of $1,719, then 

there is no point in considering a package which only achieves a 28.5% reduction in CO2

emissions for a cost of $2,333. Therefore, we removed the package for the turbocharged 

engine with a 6 speed automatic transmission and repeated the calculations. (In general, the 

package just prior to one with a negative ratio of incremental cost to incremental effectiveness 

should be removed.) The revised set of technology packages is shown in the second section 

of Table 1-14. 

The second set of packages now shows one obvious anomaly. The ratio of 

incremental cost to incremental effectiveness for the turbocharged engine with a dual clutch 

transmission is more than a factor of 10 higher than any of the others. This occurs because 

this package only reduces CO2 emissions by 0.2% over the previous package for an 

incremental cost of $700. A manufacturer would be better off applying the next package (the 

diesel) to a portion of its vehicles than to apply the turbocharged engine with a dual clutch 

transmission package to a higher percentage of its vehicles. Therefore, we removed the 

package for the turbocharged engine with the dual clutch transmission and again repeated the 

calculations. The revised set of technology packages is shown in the third section of Table 

1-14. 

The greatest anomaly in the third set of ratios is that for the diesel package. It is more 

than twice the value of the ratio for the 2-mode hybrid. If we believed that manufacturers 

would prefer to implement diesel technology over strong hybridization for some reason, we 

could have left both packages in the modeling. However, absent such a reason, we removed 

the diesel engine package from vehicle type #6. The revised set of technology packages is 

shown in the fourth section of Table 1-14. 

The greatest anomaly in the fourth section of the table is that the ratio of incremental 

cost to incremental effectiveness for the engine with cylinder deactivation and a dual clutch 

transmission is much lower than those for the two prior packages. In order to assess the 

benefit of removing the two prior packages, we do so in the fifth and last section of Table 

1-14. As can be seen, the ratio of incremental cost to incremental effectiveness for the engine 

with cylinder deactivation and a dual clutch transmission increases to over $6,184. This is 

only marginally lower than the ratios for the two packages which have been excluded. 

Retaining the two packages provides a more gradual application of technology. This provides 

the model the choice of applying technology which is currently widespread in the fleet (6-

speed automatic transmissions and 12 volt electrical systems) to a greater percentage of sales 
Draft Regulatory Impact Analysis 

1-26 

before applying more extensive technology (dual clutch transmissions and start stop 

technology). Therefore, we did not exclude the two technologies based on a strict use of the 

ratio of incremental cost to incremental effectiveness. 

1.4 EPA’s Lumped Parameter Approach for Determining Effectiveness 

Synergies 

EPA engineers reviewed existing tools that could be used to develop estimates of the 

technology synergies, including the NEMS model.1

 However, the synergies in the NEMS 

model depend heavily upon an assumed technology application flow path; those technologies 

that the model would apply first would be expected to have fewer synergies than those applied 

later on. For this reason, and because this report includes many new technologies not 

available in NEMS, it was necessary for EPA to develop its own set of estimates. EPA used a 

well-documented engineering approach known as a lumped-parameter technique to determine 

values for synergies. At the same time, however, EPA recognized the availability of more 

robust methods for determining the synergistic impacts of multiple technologies on vehicle 

CO2 emissions than the lumped-parameter approach, particularly with regard to applying 

synergy effects differentiated across different vehicle classes, and therefore augmented this 

approach with the detailed vehicle simulation modeling described in Section 1.4.7. 

The basis for EPA’s lumped parameter analysis is a first-principles energy balance 

that estimates the manner in which the chemical energy of the fuel is converted into various 

forms of thermal and mechanical energy on the vehicle. The analysis accounts for the 

dissipation of energy into the different categories of energy losses, including each of the 

following: 

 Second law losses (thermodynamic losses inherent in the combustion of fuel), 

 Heat lost from the combustion process to the exhaust and coolant, 

 Pumping losses, i.e., work performed by the engine during the intake and exhaust 

strokes, 

 Friction losses in the engine, 

 Transmission losses, associated with friction and other parasitic losses, 

 Accessory losses, related directly to the parasitics associated with the engine 

accessories and indirectly to the fuel efficiency losses related to engine warmup, 

 Vehicle road load (tire and aerodynamic) losses; 

with the remaining energy available to propel the vehicle. It is assumed that the baseline 

vehicle has a fixed percentage of fuel lost to each category. 

Each technology is categorized into the major types of engine losses it reduces, so that 

interactions between multiple technologies applied to the vehicle may be determined. When a 

technology is applied, its effects are estimated by modifying the appropriate loss categories by 

a given percentage. Then, each subsequent technology that reduces the losses in an already 

improved category has less of a potential impact than it would if applied on its own. Table 
Technology Packages, Cost and Effectiveness 

1-27 

1-15 below is an example spreadsheet used by EPA to estimate the synergistic impacts of a 

technology package for a standard-size car. 

Table 1-15 Sample Lumped Parameter Spreadsheet 

EPA Staff Deliberative Materials--Do Not Quote or Cite

Vehicle type: Standard Car Description: Technology picklist

Family Package: Z

Heat 

Lost To

Vehicle Parasitics Gearbox, Exhaust &

Mass Drag Tires T.C. Coolant

Inertia Aero Rolling Access Trans Friction Pumping Ind Eff Second

Load Load Load Losses Losses Losses Losses Losses Law Check

13.0% 4.0% 4.0% 1.8% 4.2% 6.6% 4.4% 32.0% 30.0% 100.0% OK

0% 16% 8% 64% 33% 16% 75%

13.0% 3.4% 3.7% 0.8% 3.3% 5.6% 1.1% 31.8% 30%

Indicated Mech Brake Drivetrain Fuel Road

Efficiency Efficiency Efficiency Efficiency Efficiency Loads

Baseline 38.0% 71.1% 27.0% 77.8% 21.0% 100.0%

New 38.2% 82.5% 31.5% 87.2% 27.5% 95.4%

PMEP Brake

72.9% Fuel Consumption Original friction/brake ratio Losses Efficiency

27.1% FC Reduction Based on PMEP/IMEP >>>> 11% 27%

37.2% FE Improvement (GM study) =71.1% mech efficiency

N/A Diesel FC Reduction

Independent User Picklist

Technology FC Estimate Loss Category Implementation into estimator Include? (0/1) Gross FC Red

Aero Drag Reduction 3.0% Aero 16% aero (cars), 10.5% aero (trucks) 1 3.0%

Rolling Resistance Reduction 1.5% Rolling 8% rolling 1 1.5%

Low Fric Lubes 0.5% Friction 2% friction 1 0.5%

EF Reduction 2.0% Friction 8.5% friction 1 2.0%

ICP 2.0% Pumping 12% pumping, 38.2% IE, -2% fric 0 0.0%

DCP 3.0% total VVT Pumping 18.5% pumping, 38.2% IE, -2% fric 0 0.0%

CCP 3.0% total VVT Pumping 18.5% pumping, 38.2% IE, -2% fric 1 3.0%

Deac 6.0% Pumping, friction 39% pumping 0 0.0%

DVVL 4.0% Pumping 30% pumping, -3% friction 1 4.0%

CVVL 5.0% Pumping 37% pumping, -3% friction 0 0.0%

Camless 10.0% Pumping 76% pumping, -5% friction 0 0.0%

GDI 1.5% Ind Eff 38.6% Ind Eff 0 0.0%

Turbo/Dnsize 6.0% Pumping 39% pumping 0 0.0%

5-spd 2.5% Trans, pumping 22% pumping, -5% trans 0 0.0%

CVT 6.0% Trans, pumping 46% pumping, -5% trans 0 0.0%

ASL 1.5% Pumping 9.5% pumping 1 1.5%

Agg TC Lockup 0.5% Trans 2.5% trans 1 0.5%

6-spd auto 5.5% Trans, pumping 42% pumping, -5% trans 1 5.5% Or #44/45

AMT 6.5% Trans 35% trans (increment) 1 6.5%

42V S-S 7.5% F, P, A 13% friction, 19% pumping, 38% access 1 7.5%

12V acc + Imp alt 1.5% Access 18% access 0 0.0% Or #53

EPS 1.5% Access 18% access 1 1.5%

42V acc + imp alt 3.0% Access 36% access 1 3.0% Or #51

HCCI dual-mode 11.0% Ind. Eff, pumping 41% IE, 25% pumping 0 0.0%

GDI (lean) 10.5% Ind. Eff, pumping 40% IE, 38% pumping 0 0.0%

Diesel - LNT 30.0% over gas Ind Eff, pumping 48% IE, 85% pumping, -13% friction 0 0.0%

Diesel - SCR 30.0% over gas Ind Eff, pumping 46% IE, 80% pumping, -13% friction 0 0.0%

Opt. E25 8.5% Ind. Eff, pumping 39% IE, 40% pumping 0 0.0%

33.6%

% of original fuel

Pick one or 

6-spd

Pick one

Vehicle Energy Effects Estimator

Pick one

Pick one

Current Results

Indicated Energy

Brake Energy Engine Friction

Road Loads

Baseline % of fuel

Reduction
Draft Regulatory Impact Analysis 

1-28 

Table 1-16 below lists the technologies considered in this example, their 

corresponding individual technology effectiveness values, and a comparison of the gross 

combined package CO2 reduction (i.e. disregarding synergies) to the lumped parameter 

results. The difference is the implied synergistic effects of these technologies combined on a 

package. 

Table 1-16 Comparison of Lumped Parameter Analysis with Standard Car Package 

TECHNOLOGY INDIVIDUAL CO2

REDUCTION 

CUMULATIVE CO2

REDUCTION 

Aero Drag 3% 3% 

Rolling Resistance Reduction 1.5% 4.5% 

Low Friction Lubricants 0.5% 4.9% 

 Engine Friction Reduction 2.0% 6.8% 

VVT – Coupled Cam Phasing 3.0% 9.6% 

VVT – Discrete Variable Lift 4.0% 13.2% 

Aggressive Shift Logic 1.5% 14.5% 

Early Torque Convertor Lock-up 0.5% 15.0% 

6-speed Automatic Transmission 5.5% 19.6% 

6-speed Dual Clutch Transmission 6.5% 24.9% 

Stop-start with 42 volt system 7.5% 30.5% 

Electric Power Steering 1.5% 31.5% 

42V acc + improved alternator 3.0% 33.6% 

Gross combined effectiveness 33.6% 

Lumped Parameter Estimate 27.1% 

Estimated synergistic effects -6.5% 

The synergy estimates obtained using the lumped parameter technique were 

subsequently compared to the results from the vehicle simulation work. EPA will continue to 

use the lumped parameter approach as an analytical tool, and (using the output data from the 

vehicle simulation as a basis) may adjust the synergies as necessary in the future. 

1.4.1 Ricardo’s Vehicle Simulation 

Vehicle simulation modeling was performed by Ricardo, Inc. The simulation work 

addressed gaps in existing synergy modeling tools, and served to both supplement and update 

the earlier vehicle simulation work published by NESCCAF. Using a physics-based, secondby-second model of each individual technology applied to various baseline vehicles, the 

Ricardo model was able to estimate the effectiveness of the technologies acting either 

individually or in combination. This information could then be used to estimate the synergies 

of these technology combinations, and also to differentiate the synergies across different 

vehicle classes. 
Technology Packages, Cost and Effectiveness 

1-29 

In total, Ricardo modeled five baseline vehicles and twenty-six distinct technology 

combinations, covering the full range of gasoline and diesel powertrain technologies used in 

the Volpe model, with the exception of the powersplit, plug-in and two-mode hybrid vehicle 

technologies. The five generalized vehicle classes modeled were a standard car, a full-size 

car, a small multi-purpose vehicle (MPV), a large MPV and a large truck. The complete list 

of vehicles and technology packages is given below in this section, along with a detailed 

explanation of the selection criteria. 

Each technology package was modeled under a constraint of “equivalent 

performance” to the baseline vehicle. To quantify the performance, a reasonably 

comprehensive, objective set of vehicle performance criteria were used as a basis to compare 

with the baseline vehicle, characterizing the launch acceleration, passing performance and 

grade capability that a vehicle buyer might expect when considering a technology package. 

The main metrics used to compare vehicle performance are listed below in Table 1-17. 

Table 1-17 Performance Metrics Used as Basis for “Equivalent Performance” 

CHARACTERISTIC PERFORMANCE METRIC 

Overall Performance Time to accelerate from 0-60 MPH 

Launch Acceleration Time to accelerate from 0-30 MPH 

Vehicle speed and distance after a 3-second acceleration 

from rest 

Passing Performance Time to accelerate from 30 to 50 MPH 

Time to accelerate from 50 to 70 MPH 

Maximum % grade at 70 MPH 

(standard car, large car, small MPV and large MPV) 

Grade Capability 

Maximum % grade at 60 MPH at GCVWR (large truck) 

Notes: All accelerations are assumed at WOT (wide open throttle) condition. GCVWR = Gross Combined 

Vehicle Weight Rating 

A summary of the vehicle simulation results is given below in Section 1.4.7, including 

the CO2 emissions reduction effectiveness for each technology package. The full Ricardo 

vehicle simulation results, including the acceleration performance data, may be found in 

Ricardo’s final report posted publicly at EPA’s website.2

1.4.2 Description of Ricardo’s Report 

In this section, the structure, methodology and results from the Ricardo vehicle 

simulation report are summarized. EPA worked closely with Ricardo to develop baseline 

models of five generalized vehicle classes that could be validated against EPA certification 

data, and then used as a platform upon which to add various technology packages. The 

vehicle simulation modeling results generated by Ricardo consist of the following: 

 Baseline vehicle characterization, to determine the baseline fuel consumption and CO2

emissions over the EPA combined cycle federal test procedure (FTP) for five baseline 

vehicles, for validation with EPA certification data. 

 Simulation of the vehicle technology combinations (applied to the baseline vehicles) 
Draft Regulatory Impact Analysis 

1-30 

 Incremental technology effectiveness estimates, to examine the effect of adding 

technologies one-by-one. These could then be used more directly to validate synergies 

estimated using the lumped parameter method. 

This section describes the selection process for each of the baseline vehicles and the 

technology packages, and summarizes the results of the vehicle simulation. 

1.4.3 Determination of representative vehicle classes 

In an effort to establish a reasonable scope for the vehicle simulation work and to 

update the earlier simulation done by NESCCAF, EPA chose five representative vehicle 

classes as the basis for evaluating technology benefits and synergies, representing the vehicle 

attributes of the projected highest-volume light-duty car and truck sales segments. These five 

classes covered a broad range of powertrain and vehicle characteristics, over which the 

effectiveness and synergies of each of the technologies could be evaluated. The main 

distinguishing attributes of the five vehicle classes considered by EPA and Ricardo are given 

below in Table 1-18. 

Table 1-18 Attributes of the Five Generalized Vehicle Classes Considered by Ricardo 

VEHICLE 

CLASS 

STANDARD 

CAR 

LARGE 

CAR 

SMALL 

MPV 

LARGE 

MPV 

LARGE 

TRUCKS 

EPA Vehicle 

Types Included 

Compact, 

Midsize 

Large CAR Small SUV, 

Small 

Pickup 

Minivans, 

Mid-SUV’s 

Large SUV’s, 

Large Pickups 

Curb Weight 

Range 

2800-3600 lbs >3600 lbs 3600-4200 

lbs 

4200-4800 lbs >4800 lbs 

Engine Type I4 V6 I4 V6 V8 

Drivetrain FWD RWD/AWD FWD FWD/AWD 4WD 

Body Type Unibody Unibody Unibody Unibody Ladder Frame 

Towing 

Capability 

None None Partial Partial Full 

Example vehicles Toyota Camry, 

Chevy Malibu, 

Honda Accord 

Chrysler 300, 

Ford 500 / 

Taurus 

Saturn Vue, 

Ford 

Escape, 

Honda CRV 

Dodge Grand 

Caravan, 

GMC Acadia, 

Ford Flex 

Ford F-150, 

Chevy 

Silverado 

1500, Dodge 

Ram 

EPA then selected representative vehicle models for each of these classes, based on three 

main criteria: 

 The vehicle should possess major attributes and technology characteristics that are 

near the average of its class, including engine type and displacement, transmission 

type, body type, weight rating, footprint size and fuel economy rating. 
Technology Packages, Cost and Effectiveness 

1-31 

 It should be among the sales volume leaders in its class, or where there is not a 

clearly-established volume leader, the model should share attributes consistent with 

major sellers. 

 The vehicle should have undergone a recent update or redesign, such that the 

technology in the baseline model could be considered representative of vehicles sold 

at the beginning of the proposed regulatory timeframe. 

Consideration was also given to include the sales-leading vehicle manufacturers 

among the baseline models. Hence, the U. S. domestic manufacturers account for four of the 

five models (Chrysler 300, GM/Saturn Vue, Chrysler/Dodge Caravan, and the Ford F-150), 

while import manufacturers are represented in their strongest sales segment, the standard car 

class, by the Toyota Camry. 

1.4.4 Description of Baseline Vehicle Models 

The baseline vehicles selected to represent their respective vehicle classes are 

described below in Table 1-19, listed with the critical attributes that EPA used as selection 

criteria. While each attribute for these baseline vehicles does not match the precise average 

for its class, each of these baselines is an actual vehicle platform that allows validation of the 

simulation data with “real world” certification data. 
Draft Regulatory Impact Analysis 

1-32 

Table 1-19 Description of Baseline Vehicles 

*-Estimated CO2 equivalent, taken from EPA adjusted combined fuel economy 

ratings. 

1.4.5 Technologies Considered by EPA and Ricardo in the Vehicle Simulation 

A number of advanced gasoline and diesel technologies were considered in the 

Ricardo study, comprising the majority of the technologies used in the Volpe model, with the 

exception of the hybrid electric vehicle technologies. In developing a comprehensive list of 

technologies to be modeled, EPA surveyed numerous powertrain and vehicle technologies 

and technology trends, in order to assess their potential feasibility in the next one to ten years. 

VEHICLE CLASS STANDARD 

CAR 

LARGE 

CAR 

SMALL 

MPV 

LARGE 

MPV 

LARGE 

TRUCKS 

Baseline Vehicle Toyota 

Camry Chrysler 300 Saturn 

VUE 

Dodge Grand 

Caravan Ford F-150 

CO2 Emissions* 

(g/mi) 327 409 415 435 575 

Base Engine DOHC I4 SOHC V8 DOHC I4 OHV V6 SOHC V8 

Displacement 

(L) 2.4 3.5 2.4 3.8 5.4 

Rate Power 

(HP) 154 250 169 205 300 

Torque (ft-lbs) 160 250 161 240 365 

Valvetrain Type VVT (DCP) Fixed VVT (DCP) Fixed VVT (CCP) 

Valves/Cylinder 4 4 4 2 3 

Drivetrain FWD RWD FWD FWD 4WD 

Transmission Auto Auto Auto Auto Auto 

# of Forward 

Speeds 5 5 4 4 4 

Curb Weight 

(lbs) 3108 3721 3825 4279 5004 

ETW (lbs) 3500 4000 4000 4500 6000 

GVWR (lbs) -- -- 4300 5700 6800 

GCWR (lbs) -- -- -- -- 14000 

Front Track 

Width (in.) 62 63 61.4 63 67 

Vehicle Attributes 

Wheelbase (in.) 109.3 120 106.6 119.3 144.5 

Displacement / 

Weight Ratio 

(L/ton) 

1.54 1.88 1.25 1.78 2.16 

Performance 

Characteristics 

Power / 

Weight Ratio 

(HP/ton) 

99.1 134.4 88.4 95.8 119.9 
Technology Packages, Cost and Effectiveness 

1-33 

The list of technologies considered therefore includes those that are available today (e.g., 

variable valve timing, six-speed automatic transmissions) as well as some that may not be 

ready for five to ten years (e.g., camless valve actuation and HCCI engines). Table 1-20 

below lists the technologies that Ricardo included in the vehicle simulation models. 

Table 1-20 Technologies Included in the Ricardo Vehicle Simulation 

ENGINE TECHNOLOGIES 

Abbreviation Description 

DOHC Dual Overhead Camshafts 

SOHC Single Overhead Camshaft 

OHV Overhead Valve (pushrod) 

CCP Couple Cam Phasing 

DCP Dual (independent) Cam Phasing 

DVVL Discrete (two-step) Variable Valve Lift 

CVVL Continuous Variable Valve Lift 

Deac Cylinder Deactivation 

CVA Camless Valve Actuation (full) 

Turbo Turbocharging and engine downsizing 

GDI Gasoline Direct Injection 

Diesel Diesel with advanced aftertreatment 

HCCI Homogenous Charge Compression Ignition (gasoline) 

LUB Low-friction engine lubricants 

EFR Engine Friction Reduction 

TRANSMISSION TECHNOLOGIES 

Abbreviation Description 

L4 Lock-up 4-speed automatic transmission 

L5 Lock-up 5-speed automatic transmission 

L6 Lock-up 6-speed automatic transmission 

DCT6 6-speed Dual Clutch Transmission 

CVT Continuously Variable Transmission 

ASL Aggressive Shift Logic 

TORQ Early Torque Converter Lock-up 

ACCESSORY TECHNOLOGIES 

Abbreviation Description 

ISG (42V) 42V Integrated Starter-Generator 

EPS Electric Power Steering 

EACC Electric Accessories (water pump, oil pump, fans) 

HEA High-Efficiency Alternator 

VEHICLE TECHNOLOGIES 

Abbreviation Description 

AERO Aerodynamic drag reduction (10~20%) 

ROLL Tire Rolling Resistance reduction (10%) 
Draft Regulatory Impact Analysis 

1-34 

1.4.6 Choice of Technology Packages 

EPA chose a number of technology packages representing a range of options that 

manufacturers might pursue. In determining these technology combinations, EPA considered 

available cost and effectiveness numbers from the literature, and applied engineering 

judgment to match technologies that were compatible with each other and with each vehicle 

platform. Also, where appropriate, the same technologies were applied to multiple vehicle 

classes, to determine where specific vehicle attributes might affect their benefits and 

synergies. Table 1-21 below describes in detail the technology content in each technology 

package simulated by Ricardo. 

Table 1-21 Description of the Vehicle Technology Packages Modeled by Ricardo 

VEHICLE 

CLASS 

TECHNOLOGY 

PACKAGE ENGINE VALVETRAIN TRANSMISSION ACCESSORIES 

Baseline 2.4 Liter I4 DOHC, DCP L5 -- 

Z 2.4L I4, PFI CCP, DVVL DCT6 ISG (42V), EPA, 

EACC 

1 2.4L I4, GDI DCP, DVVL CVT EPS, EACC, HEA 

Standard 

Car 

2 2.4L I4, GDI DCP L6 ISG (42V), EPS, 

EACC 

Baseline 2.4 Liter I4 DOHC, DCP L6 EPS 

Z 2.4L I4, PFI CCP, DVVL DCT6 ISG (42V), EPA, 

EACC 

1 2.4L I4, GDI DCP, DVVL CVT EPS, EACC, HEA 

2 2.4L I4, GDI DCP L6 ISG (42V), EPA, 

EACC 

15 1.5L I4, GDI, 

Turbo DCP DCT6 EPS, EACC, HEA 

15a 2.4L I4, GDI CVA DCT6 EPS, EACC, HEA 

15b 2.4L I4, GDI, 

HCCI DCP, CVVL DCT6 EPS, EACC, HEA 

 Small MPV 

5 1.9L I4, Diesel DOHC DCT6 EPS, EACC, HEA 

Baseline 3.5 Liter V6 SOHC L5 -- 

4 2.2L I4, GDI, 

Turbo DCP L6 EPS, EACC, HEA 

5 2.8L I4, Diesel DOHC DCT6 EPS, EACC, HEA 

Y1 3.5L V6, GDI CVA DCT6 EPS, EACC, HEA 

Y2 3.5L V6, GDI, 

HCCI DCP, CVVL DCT6 EPS, EACC, HEA 

6a 3.0L V6, GDI DCP, CVVL DCT6 EPS, EACC, HEA 

 Full Size Car 

16 3.5L V6, GDI CCP, Deac L6 ISG (42V), EPA, 

EACC 

Baseline 3.8 Liter V6 OHV L4 -- 

4 2.1L I4, GDI, 

Turbo DCP L6 EPS, EACC, HEA 

6b 3.0L V6, GDI CCP, Deac DCT6 EPS, EACC, HEA 

Large MPV 

16 3.8L V6, GDI CCP, Deac L6 ISG (42V), EPA, 

EACC 

Baseline 5.4 Liter, V8 SOHC, CCP L4 -- 

9 5.4L V8, GDI CCP, Deac DCT6 ISG (42V), EPA, 

Large 

Truck 

EACC 

10 3.6L V6, GDI, DCP DCT6 EPS, EACC, HEA 
Technology Packages, Cost and Effectiveness 

1-35 

Turbo 

11 4.8L V8, Diesel DOHC DCT6 EPS, EACC, HEA 

12 5.4L V8, GDI CCP, Deac L6 ISG (42V), EPA, 

EACC 

17 5.4L V8, GDI DCP, DVVL L6 EPS, EACC, HEA 

X1 5.4L V8, GDI CVA DCT6 EPS, EACC, HEA 

X2 5.4L V8, GDI, 

HCCI DCP, CVVL DCT6 EPS, EACC, HEA 

Other: 20% Aerodynamic drag reduction, 10% tire rolling resistance reduction assumed for all 

vehicles, except Large Trucks. 10% Aerodynamic drag reduction assumed for Large Truck. Low-Friction 

lubricants and moderate engine friction reductions are assumed for all vehicles. Aggressive shift logic and early 

torque converter lockup strategies are assumed for all vehicles, where applicable. 

1.4.7 Simulation Results 

The CO2 emissions results from the vehicle simulation are summarized below in Table 

1-22 (for cars) and Table 1-23 (for light-duty trucks). The CO2 estimates are given for the 

combined city and highway test cycles, according to the EPA Federal Test Procedure (FTP), 

with the technology package results compared with the baseline vehicle as shown. 

It is important to reiterate that each of the technology package results were obtained 

with performance determined to be equivalent to the baseline vehicle. No attempt was made 

to project trends in performance during the proposed regulatory period, nor was the 

performance downgraded to give improved fuel efficiency. A full comparison of vehicle 

acceleration performance is given in the Ricardo final report. 

Table 1-22 CO2 Emissions Estimates Obtained from Vehicle Simulation (Cars) 

CO2

CITY 

CO2

HWY 

CO2

COMB 

CO2 

REDUCTION 

VEHICLE TECHNONOLGY 

PACKAGE 

MAJOR 

FEATURES* 

g/mi g/mi g/mi % 

Baseline 2.4L I4, DCP, L5 338 217 284 -- 

Z CCP, DVVL, 

DCT, ISG 250 170 214 24.7% 

1 GDI, DCP, 

DVVL, CVT 294 198 251 11.5% 

Standard Car

2 GDI, DCP, L6, 

ISG 277 180 233 17.8% 

Baseline 3.5L V6, L5 420 279 356 -- 

4 2.2L I4, GDI, 

Turbo, DCP, L6 346 236 296 16.9% 

5 2.8L I4 Diesel, 

DCT 315 221 273 23.5% 

Full Size 

Car

Y1 GDI, CVA, DCT 278 199 242 32.0% 
Draft Regulatory Impact Analysis 

1-36 

Y2 GDI, HCCI, DCT 290 197 248 30.4% 

6a GDI, DCP, 

CVVL, DCT 331 235 288 19.2% 

16 GDI, CCP, Deac, 

L6, ISG 301 205 257 27.7% 

*-Please refer to Table 1-20 for a full description of the vehicle technologies 

Table 1-23 CO2 Emissions Estimates Obtained from Vehicle Simulation (Light-Duty Trucks) 

CO2

CITY 

CO2

HWY 

CO2

COMB 

CO2 

REDUCTION 

VEHICLE TECHNONOLGY 

PACKAGE 

MAJOR 

FEATURES* 

g/mi g/mi g/mi % 

Baseline 2.4L I4, DCP, EPS 367 253 316 -- 

Z CCP, DVVL, DCT, 

ISG 272 208 243 23.0% 

1 GDI, DCP, DVVL, 

CVT 310 227 272 13.7% 

2 GDI, DCP, L6, ISG 291 211 255 19.3% 

15 1.5L I4 GDI, Turbo, 

DCP, DCT 272 212 245 22.5% 

15a GDI, CVA, DCT 262 193 231 26.8% 

15b GDI, HCCI, DCT 270 197 237 24.8% 

Small MPV 

5 1.9L I4 Diesel, DCT 282 205 247 21.8% 

Baseline 3.8L V6 458 313 393 -- 

4 2.1L I4, GDI, Turbo, 

DCP, L6 357 256 312 20.6% 

6b GDI, CCP, Deac, DCT 333 248 295 24.9% 

Large MPV 

16 GDI, CCP, Deac, L6, 

ISG 325 225 280 28.7% 

Baseline 5.4L V8, CCP 612 402 517 -- 

9 GDI, CCP, Deac, DCT, 

ISG 432 315 379 26.7% 

10 3.6L V6, GDI, Turbo, 

DCP, DCT 404 319 366 29.3% 

11 4.8L V8 Diesel, DCT 444 326 391 24.4% 

12 GDI, CCP, Deac, L6, 

ISG 459 328 400 22.6% 

17 GDI, DCP, DVVL, L6 492 333 420 18.8% 

X1 GDI, CVA, DCT 422 314 374 27.8% 

Large Truck 

X2 GDI, HCCI, DCT 425 311 374 27.7% 

*-Please refer to Table 1-20 for a full description of the vehicle technologies 

1.5 Comparison of Lumped-Parameter Results to Modeling Results 

Considering the following: 
Technology Packages, Cost and Effectiveness 

1-37 

1) EPA’s lumped-parameter package estimates are comparable with those obtained from 

the detailed Ricardo simulations. This is illustrated in Figure 1-2 below. 

2) EPA is confident in the plausibility of the individual technology effectiveness 

estimates in, based on the sources from which that information was assimilated, as 

detailed in Section 2 of this report. 

3) Additionally, EPA expresses confidence in the overall Ricardo package results due to 

the robust methodology used in building the models and generating the results. 

0%

5%

10%

15%

20%

25%

30%

35%

40%

Std CarStd CarStd Car

Sm MPVSm MPVSm MPVSm MPVSm MPVSm MPVSm MPV

Large CarLarge CarLarge CarLarge CarLarge CarLarge Car

Large MPVLarge MPVLarge MPV

TruckTruckTruckTruckTruckTruckTruck

Z 1 2 Z 1 2 15 15a 15b 5 4 5 6a 16 Y1 Y2 4 6b 16 9 10 11 12 17 X1 X2

Package

FC Reduction

Ricardo

L-P

Figure 1-2 Comparison of Ricardo package results to equivalent lumped parameter package results 

Based on this, EPA concludes that the synergies derived from the lumped parameter 

approach are generally plausible (with a few packages that garner additional investigation). 

EPA will continue to analyze this data, focusing on those packages where the differences 

between the two approaches are large. 

The simulation results may present opportunities to improve the fidelity of the 

lumped-parameter approach by identifying differences between different platforms or 

important vehicle traits (such as displacement-to-weight ratio, e.g.). There might also be 

opportunity to infer (through detailed analysis) the individual effectiveness values for some 

technologies by comparing and isolating Ricardo package results across different vehicle 

platforms. 
Draft Regulatory Impact Analysis 

1-38 

1.6 Using the Lumped-Parameter Technique to Determine Synergies in a 

Technology Application Flowpath (Identifying “Technology Pairs” to 

account for synergies) 

In order to account for the real world synergies of combining of two or more 

technologies, the product of their individual effectiveness values must be adjusted based on 

known interactions, as noted above. When using an approach in which technologies are 

added sequentially in a pre-determined application path to each individual vehicle model, as 

used in NHTSA’s 2006 fuel economy rule for light trucks3

, these interactions may be 

accounted for by considering a series of interacting technology pairs. EPA believes that a 

lumped parameter approach can be used as a means to estimate and account for synergies for 

such a technology application method. When using a sequential technology application 

approach which applies more than one technology, it is necessary to separately account for the 

interaction of each unique technology pair. Moreover, if the sequential technology 

application approach applies a technology that supersedes another, for example, where a 

VVLT system is substituted in place of a cylinder deactivation system, its incremental 

effectiveness must be reduced by the sum of the synergies of that technology with each 

individual technology that was previously applied, regardless of whether any of them have 

also been superseded. Figure 1-3 below provides an example of how technology pairs are 

identified for a specific technology application path similar to one used by NHTSA. In this 

example, an interaction is identified between each of the engine technologies (except GDI) 

with each of the transmission technologies. So, in this example, were the model to couple a 

turbocharged and downsized GDI engine with a 6-speed transmission, it would apply a series 

of many synergy pairs to the combined individual effectiveness values to arrive at the overall 

effectiveness. 

Engine Technology Trans Technology

VVT (ICP)

VVT (CCP) L5

DISP L6

VVLT (DVVL)

GDI

TURB

(Lines indicate potential synergies)

Figure 1-3 Illustration of technology pairings for a specific technology application path 
Technology Packages, Cost and Effectiveness 

1-39 

References 

All references can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472.

 

1

 National Energy Modeling System, Energy Information Administration, U. S. Dept of Energy. 

2

 “A Study of Potential Effectiveness of Carbon Dioxide Reducing Vehicle Technologies,” EPA Report No. 

EPA420-R-08-004, available in the EPA docket EPA-HQ-OAR-2009-0472 and on the Internet at 

http://www.epa.gov/otaq/technology/420r08004a.pdf. 

3

 NHTSA 2008-2011 CAFE FRM at 71 FR 17566. 
Draft Regulatory Impact Analysis 

2-2 

CHAPTER 2:Air Conditioning 

2.1 Overview of Air Conditioning Impacts and Technologies 

Over 95% of the new cars and light trucks in the United States are equipped with air 

conditioner (MAC) systems. In the 1970’s and 1980’s, air conditioner systems were an 

optional (luxury) feature, but it now comes standard on almost all new vehicle models. The 

Mobile Air Conditioner (A/C) system is a unique and distinct technology on the automobile. 

It is different from the other technologies described in Chapter 3 of the joint Technical 

Support Document (TSD) in several ways. First, most of the technologies described in the 

joint TSD directly affect the efficiency of the engine, transmission, and vehicle systems. As 

such, these systems are almost always active while the vehicle is moving down the road or 

being tested on a dynamometer for the fuel economy and emissions test drive cycles. A/C on 

the other hand, is a parasitic load on the engine that only burdens the engine when the vehicle 

occupants demand it. Since it is not tested as a normal part of the fuel economy and 

emissions test drive cycles, it is referred to as an “off-cycle” effect. There are many other offcycle loads that can be switched on by the occupant that affect the engine; these include 

lights, wipers, stereo systems, electrical defroster/defogger, heated seats, power windows, etc. 

However, these electrical loads individually amount to a very small effect on the engine 

(although together they can be significant). The A/C system (by itself) adds a significantly 

higher load on the engine as described later in this chapter. Secondly, present A/C systems 

leak a powerful greenhouse gas directly into the air - even when the vehicle is not in 

operation. No other vehicle system does this. Because of these factors, a distinct approach to 

control of MAC systems is justified, and a separate technical discussion is also warranted. 

As just mentioned above, there are two mechanisms by which A/C systems contribute 

to the emissions of greenhouse gases. The first is through direct leakage of the refrigerant 

into the air. The hydrofluorocarbon refrigerant compound currently used in all recent model 

year vehicles is R134a (also known as 1,1,1,2-Tetrafluoroethane, or HFC-134a). Based on 

the higher global warming potential of HFCs, a small leakage of the refrigerant has a greater 

global warming impact than a similar amount of emissions of some other mobile source 

GHGs. R134a has a global warming potential (GWP) of 1430.A This means that 1 gram of 

R134a has the equivalent global warming potential of 1,430 grams of CO2 (which has a GWP 

 A The global warming potentials (GWP) used in the NPRM analysis are consistent with Intergovernmental Panel 

on Climate Change (IPCC) Fourth Assessment Report (AR4). At this time, the IPCC Second Assessment Report 

(SAR) global warming potential values have been agreed upon as the official U.S. framework for addressing 

climate change. The IPCC SAR GWP values are used in the official U.S. greenhouse gas inventory submission 

to the United Nations climate change framework. When inventories are recalculated for the final rule, changes 

in GWP used may lead to adjustments. 
Air Conditioning 

2-3 

of 1).1

 In order for the A/C system to take advantage of the refrigerant’s thermodynamic 

properties and to exchange heat properly, the system must be kept at high pressures even 

when not in operation. Typical static pressures can range from 50-80 psi depending on the 

temperature, and during operation, these pressures can get to several hundred psi. At these 

pressures leakage can occur through a variety of mechanisms. The refrigerant can leak slowly 

through seals, gaskets, and even small failures in the containment of the refrigerant. The rate 

of leakage may also increase over the course of normal wear and tear on the system. Leakage 

may also increase more quickly through rapid component deterioration such as during vehicle 

accidents, maintenance or end-of-life vehicle scrappage (especially when refrigerant capture 

and recycling programs are less efficient). Small amounts of leakage can also occur 

continuously even in extremely “leak-tight” systems by permeating through hose membranes. 

This last mechanism is not dissimilar to fuel permeation through porous fuel lines. 

Manufacturers may be able to reduce these leakage emissions through the implementation of 

technologies such as leak-tight, non-porous, durable components. The global warming impact 

of leakage emissions also can be addressed by using alternative refrigerants with lower global 

warming potential. Refrigerant emissions can also occur during maintenance and at the end 

of the vehicle’s life (as well as emissions during the initial charging of the system with 

refrigerant), and these emissions are already addressed by the CAA Title VI stratospheric 

ozone program, as described below. 

The second mechanism by which vehicle A/C systems contribute to GHG emissions is 

through the consumption of additional fuel required to provide power to the A/C system and 

from carrying around the weight of the A/C system hardware year-round. The additional fuel 

required to run the system is converted into CO2 by the engine during combustion. These 

increased emissions due to A/C operation can be reduced by increasing the overall efficiency 

of the vehicle’s A/C system, as described below. EPA will not be addressing modifications to 

the excess weight of the A/C system, since the incremental increase in CO2 emissions and fuel 

consumption due to carrying the A/C system is directly measured during the normal federal 

test procedure, and is thus already subject to the normal control program. 

EPA’s analysis indicates that together, these (A/C related) emissions account for about 

9% of the greenhouse gas emissions from cars and light trucks. In this document, EPA will 

separate the discussion of these two categories of A/C-related emissions because of the 

fundamental differences in the emission mechanisms and the methods of emission control. 

Refrigerant leakage control is akin in many respects to past EPA fuel evaporation control 

programs (in that containment of a fluid is the key feature), while efficiency improvements 

are more similar to the vehicle-based control of CO2 set out in the joint TSD (in that they 

would be achieved through specific hardware and controls). 

EPA recognizes that California and the European Union also believe that A/C related 

emissions account for a significant part of greenhouse gas emissions. Both California and the 

European Union have either proposed or discussed programs to limit GHGs from A/C 

systems. EPA has evaluated these programs and this document discusses some similar 

features and others that emphasize additional emission reduction mechanisms. 
Draft Regulatory Impact Analysis 

2-4 

2.2 Air Conditioner Leakage 

2.2.1 Impacts of Refrigerant Leakage on Greenhouse Gas Emissions 

There have been several studies in the literature which have attempted to quantify the 

emissions (and impact) of air conditioner HFC emissions from light duty vehicles. In this 

section, several of these studies are discussed. 

2.2.1.1 In-Use Leakage Rates 

Based on measurements from 300 European vehicles (collected in 2002 and 2003), 

Schwarz and Harnisch estimate that the average HFC direct leakage rate from modern A/C 

systems was estimated to be 53 g/yr.2

 This corresponds to a leakage rate of 6.9% per year. 

This was estimated by extracting the refrigerant from recruited vehicles and comparing the 

amount extracted to the amount originally filled (as per the vehicle specifications). The fleet 

and size of vehicles differs from Europe and the United States, therefore it is conceivable that 

vehicles in the United States could have a different leakage rate. The authors measured the 

average charge of refrigerant at initial fill to be about 747 grams (it is somewhat higher in the 

U.S. at 770g), and that the smaller cars (684 gram charge) emitted less than the higher charge 

vehicles (883 gram charge). Moreover, due to the climate differences, the A/C usage patterns 

also vary between the two continents, which may influence leakage rates. 

Vincent et al., from the California Air Resources Board estimated the in-use 

refrigerant leakage rate to be 80 g/yr.3

 This is based on consumption of refrigerant in 

commercial fleets, surveys of vehicle owners and technicians. The study assumed an average 

A/C charge size of 950 grams and a recharge rate of 1 in 16 years (lifetime). The recharges 

occurred when the system was 52% empty and the fraction recovered at end-of-life was 8.5%. 

2.2.1.2 Emission Inventory 

The EPA publishes an inventory of greenhouse gases and sinks on an annual basis. 

The refrigerant emissions numbers that are used in the present analysis are from the Vintaging 

model, which is used to generate the emissions included in this EPA inventory source. The 

HFC refrigerant emissions from light duty vehicle A/C systems was estimated to be 61.8 Tg 

CO2 equivalent in 2005 by the Vintaging model.4,B

 

In 2005, refrigerant leakage accounted for about 5.1% of total greenhouse gases from 

light duty sources. The following table shows the breakdown of greenhouse gases as broken 

down by the different emissions processes in 2005. The baseline tailpipe CO2, N2O and CH4

emissions are from MOVES, the refrigerant emissions are from the Vintaging model, and the 

A/C CO2 emissions are from EPA and the National Renewable Energy Laboratory (NREL) as 

described below. 

 B

 EPA reported the MVAC emissions at 56.6 Tg CO2 EQ, using a GWP of 1300. This number has been adjusted 

using a GWP of 1430. 
Air Conditioning 

2-5 

Table 2-1. CO2 equivalent emissions from light duty vehicles broken up by source or process. 

Emissions source or process Tg CO2 (equivalent) Percentage of total 

Tailpipe CO2 (w/o A/C) 1,076 88.6% 

CO2 from A/C 47.2 3.9% 

HFC-134a (Leakage) 61.8 5.1% 

N2O 28.2 2.3% 

CH4 1.9 0.2% 

Total 1,215 

From a vehicle standpoint, the Vintaging model assumes that 42% of the refrigerant 

emissions are due to direct leakage (or “regular” emissions), 49% for service and maintenance 

(or “irregular” emissions), and 9% occurs at disposal or end-of-life as shown in the following 

table. These are based on assumptions of the average amount of chemical leaked by a vehicle 

every year, how much is lost during service of a vehicle (from professional service center and 

do-it-yourself practices), and the amount lost at disposal. These numbers vary somewhat over 

time based on the characteristics (e.g. average charge size and leakage rate) of each “vintage” 

of A/C system, assumptions of how new A/C systems enter the market, and the number of 

vehicles disposed of in any given year. 

Table 2-2: Light duty vehicle HFC-134a emissions in 2005 from Vintaging model. HFC emissions can be 

converted to CO2 equivalent by multiplying by 1430 GWP. 

Emission Process HFC emissions (metric tons) Fraction of total 

Leakage 18,151 0.42 

Maintenance/servicing 21,176 0.49 

Disposal/end-of-life 3,890 0.09 

Total 43,217 1.0 

2.2.2 A/C Leakage Credit 

The level to which each technology can reduce leakage can be calculated using the 

SAE Surface Vehicle Standard J2727 – HFC-134a Mobile Air Conditioning System 

Refrigerant Emission Chart. This industry standard was developed by SAE and the 

cooperative industry and government IMAC (Improved Mobile Air Conditioning) program 

using industry experience, laboratory testing of components and systems, and field data to 

establish a method for calculating leakage. With refrigerant leakage rates as low as 10 g/yr, it 

would be exceedingly difficult to measure such low levels in a test chamber (or shed). Since 

the J2727 method has been correlated to “mini-shed” results (where select components are 

tested in a small chamber, simulating real-world driving cycles), the EPA considers this 

method to be an appropriate surrogate for vehicle testing of leakage. It is also referenced by 

the California Air Resources Board in their Environmental Performance Label regulation and 

the State of Minnesota in their GHG reporting regulation.5,6 

2.2.2.1 Why Is EPA Relying on a Design-Based Rule? 

As with any design-based rule, it is possible to achieve compliance by simply 

selecting the minimum number of design attributes needed to meet a particular threshold or 
Draft Regulatory Impact Analysis 

2-6 

standard. Whether a design-based approach is used for emissions compliance or earning 

voluntary GHG credits, manufacturers will rightly choose the combination of design attributes 

which yield the maximum benefit at the lowest cost. However, there is a risk that some 

manufacturers may select poor quality, cheap parts, or implement the changes poorly, 

resulting in vehicles which ostensibly meet the rule’s provisions, but in practice, fail to 

achieve their stated benefits. However, EPA believes that the market-driven incentive of 

assuring customer satisfaction will drive manufacturers to design A/C systems that perform as 

promised, and never need to be recharged. Also, it should be noted that the relative leakage 

rates assigned to various components, materials, and technologies in SAE J2727 are based on 

(and correlated to) actual leakage rates, as measured in bench- and field-test studies of 

vehicles and components. 

In the case of refrigerant leakage, it would be very costly and burdensome to design, 

develop, and implement a test procedure and facility for measuring refrigerant leakage on 

each and every vehicle type a manufacturer produces. With leakage levels on many new 

vehicles expected to be as low as 9 g/yr (0.001 g/hr), it would be difficult to accurately 

measure the actual leakage rate. Even if it were possible to build a suitable facility capable of 

accurately measuring very low levels of refrigerant leakage, such a facility would still not 

exercise the A/C system across its normal range of operation, both in terms of engine and 

vehicle speeds as well as ambient conditions (e.g. under high compressor load, leakage past 

the compressor shaft seal on a running system can be 20 times higher than the static leakage 

level).7

 In addition, it is very likely that any performance-based test would become obsolete in 

the timeframe of this rulemaking, as low-GWP refrigerants are likely to be adopted by 

manufacturers. 

In the absence of a vehicle-level performance test to measure the how a particular A/C 

system design functions (and the difficulty in creating such a test), EPA is proposing to rely 

upon the best available design metrics for quantifying system performance. EPA believes that 

the SAE J2727 method as an appropriate method for quantifying the expected yearly 

refrigerant leakage rate from A/C systems. 

2.2.2.2 How Are Credits Calculated? 

The A/C credit available to manufacturers will be calculated based on how much a 

particular vehicle’s annual leakage value is reduced against the average new vehicle, and will 

be calculated using a method drawn directly from the SAE J2727 approach. By scoring the 

minimum leakage rate possible on the J2727 components enumerated in the proposed rule 

(expressed in the proposed rule as a measure of annual leakage), one earns the maximum A/C 

credit (on a gram per mile basis). 

The A/C credit available to manufacturers will be calculated based on the reduction to 

a vehicle’s yearly leakage rate, using the following equation: 

 
Air Conditioning 

2-7 

Equation 1 – Credit Equation 

A/C Credit = (MaxCredit) * [ 1 - (§86.166-12 Score/AvgImpactC

) * (GWPRefrigerant/1430)] 

There are four significant terms to the credit equation. Each is briefly summarized below, and 

is then explained more thoroughly in the following sections. Please note that the values of 

many of these terms change depending on whether HFC-134a or an alternative refrigerant are 

used. The values are shown in Table 2-3, and are documented in the following sections. 

 “MaxCredit” is a term for the maximum amount of credit entered into the equation 

before constraints are applied to terms. The maximum credits that could be earned by 

a manufacturer is limited by the choice of refrigerant and by assumptions regarding 

maximum achievable leakage reductions. 

 “Score/AvgImpact” is the leakage score of the A/C system as measured according to 

the §86.166-12 calculation in units of g/yr, where the minimum score which is deemed 

feasible is fixed. 

 “AvgImpact” is the annual average impact of A/C leakage. 

 “GWPRefrigerant” is the global warming potential for direct radiative forcing of the 

refrigerant as defined by EPA (or IPCC). 

Table 2-3: Components of the A/C Credit Calculation 

 HFC-134a 

Alternative 

Refrigerant 

 Cars Trucks Cars Trucks 

MaxCredit equation input (grams /mile CO2 EQ) 12.6 15.6 13.8 17.2 

A/C credit maximum (grams /mile CO2 EQ) 6.3 7.8 13.8 17.2 

§86.166-12 Score AvgImpact (grams / HFC year) 8.3 10.4 8.3 10.4 

Avg Impact (grams / HFC year) 16.6 20.7 16.6 20.7 

2.2.2.2.1 Max Credit Term 

In order to determine the maximum possible credit on a gram per mile basis, it was 

necessary to determine the projected real world HFC emissions per mile in 2016. Because 

HFC is a leakage type emission, it is largely disconnected from vehicle miles traveled 

 C

 Proposed section 86.166-12 sets out the individual component leakage values based on the SAE value. 
Draft Regulatory Impact Analysis 

2-8 

(VMT).D Consequently, the total HFC inventory in 2016 was calculated, and then calculated 

the relevant VMT. The quotient of these two terms is the HFC contribution per mile. 

Consistent with the methodology presented in DRIA chapter 5, the HFC emission 

inventories were estimated from a number of existing data sources. The per-vehicle per-year 

HFC emission of the current (reference) vehicle fleet was determined using averaged 2005 

and 2006 registration data from the Transportation Energy Databook (TEDB) and 2005 and 

2006 mobile HFC leakage estimates from the EPA Emissions and Sinks report described 

above.8,9 The per-vehicle per-year emission rates were then adjusted to account for the new 

definitions of car and truck classes (described in preamble section I), by increasing the car 

contribution proportionally by the percentage of former trucks that are reclassified as cars. 

This inventory calculation assumes that the leakage rates and charge sizes of future fleets are 

equivalent to the fleet present in the 2005/2006 reference years. Preliminary EPA analysis 

indicates that this may increasingly overstate the future HFC inventory, as charge sizes are 

decreasing. 

The per-vehicle per-year average emission rate was then scaled by the projected 

vehicle fleet in each future year (using the fleet predicted in the emissions analysis) to 

estimate the HFC emission inventory if no controls were enacted on the fleet. After dividing 

the 2016 inventory by total predicted VMT in 2016, an average per mile HFC emission rate 

(“base rate”) was obtained. 

The base rate is an average in-use number, which includes both old vehicles with 

significant leakage, as well as newer vehicles with very little leakage. The new vehicle 

leakage rate is discussed in section 2.2.2.2.2, while deterioration is discussed in section 2.2.5. 

 Max Credit with Conventional Refrigerant (HFC-134a)

Two adjustments were made to the base rate in order to calculate the Maximum HFC 

credit with conventional refrigerant. First, EPA has determined that 50% leakage 

prevention is the maximum potentially feasible prevention rate in the 2012-2016 

timeframe (section 2.2.3). Some leaks will occur and are expected, regardless of 

prevention efforts. The accuracy of the J2727 approach (as expressed in proposed 

§86.112), as a design based test, decreases as the amount of expected leakage 

diminishes. 50% of the base rate is therefore proposed to be set as the maximum 

potential leakage credit for improvements to HFC leakage using conventional 

refrigerant. 

Second, EPA expects that improvements to conventional refrigerant systems will 

affect both leakage and service emissions, but will not affect end of life emissions. 

EPA expects that reductions in the leakage rate from A/C systems will result in fewer 

visits for maintenance and recharges. This will have the side benefit of reducing the 

emissions leftover from can heels (leftover in the recharge cans) and the other releases 

 D In short, leakage emissions occur even while the car is parked, so the connection to a gram/mile credit is not 

straightforward. However, HFC emissions must be converted to a gram/mile basis in order to create a relevant 

credit. 
Air Conditioning 

2-9 

that occur during maintenance. However, as disposal/end of life emissions will be 

unaffected by the leakage improvements (and also are subject to control under the 

rules implementing Title VI of the CAA), the base rate was decreased by a further 9% 

(Table 2-2). 

 Max Credit with Alternative Refrigerant 

Emission reductions greater than 50% are possible with alternative refrigerants. As an 

example, if a refrigerant with a GWP of 0 were used, it would be possible to eliminate 

all refrigerant GHG emissions. In addition, for alternative refrigerants, the EPA 

believes that vehicles with reduced GWP refrigerants should get credit for end of life 

emission reductions. Thus, the maximum credit with alternative refrigerant is about 

9% higher than twice the maximum leakage reduction. 

A final adjustment was made to each credit to account for the difference between realworld HFC emissions and test-cycle CO2 emissions. It has been shown that the tests currently 

used for CAFE certification represents an approximately 20% gap from real world fuel 

consumption and the resulting CO2 emissions.10 Because the credits from direct a/c 

improvements are taken from a real world source, and are being traded for an increase in fuel 

consumption due to increased CO2 emissions, the credit was multiplied by 0.8 to maintain 

environmental neutrality (Table 2-4). 

Table 2-4 HFC Credit Calculation for Cars and Trucks based on a GWP of 1430 

 HFC 

Inventory 

(MMT 

CO2 EQ) 

VMT 

(Billions 

of Miles) 

Total HFC 

EmissionsPer 

Mile 

(CO2 EQ 

Gram/mile) 

HFC 

Leakage and 

Service 

EmissionsPer 

Mile 

(CO2 EQ 

Gram/mile) 

Maximum 

Credit w/ 

alternative 

refrigerant 

 (Adjusted 

for Onroad gap & 

including 

end of life)

Maximum 

Credit w/o 

alternative 

refrigerant 

(50% of 

Adjusted 

HFC & 

excluding 

end of life) 

Car 27.4 1,580 17.2 15.5 13.8 6.3 

Truck 30.4 1,392 21.5 19.6 17.2 7.8 

Total 57.8 2,972 18.6 16.9 14.9 6.8 

2.2.2.2.2 Proposed section 86.166-12, implementing the J2727 Score Term 

The J2727 score is the SAE J2727 yearly leakage estimate of the A/C system as 

calculated according to the J2727 procedure. The minimum score for cars and trucks is a 

fixed value, and the section below describes the derivation of the minimum leakage scores 

that can be achieved using the J2727 procedure. 

In contrast to the studies discussed in section 2.2.1.1 which discussed the HFC 

emission rate of the in-use fleet (which includes vehicles at all stages of life), the SAE J2727 

estimates leakage from new vehicles. In the development of J2727, two relevant studies were 
Draft Regulatory Impact Analysis 

2-10 

assessed to quantify new vehicle emission rates. In the first study, measurements from 

relatively new (properly functioning and manufactured) Japanese-market vehicles were 

collected. This study was based on 78 in-use vehicles (56 single evap, 22 dual evap) from 7 

Japanese auto makers driven in Tokyo and Nagoya from April, 2004 to December, 2005. The 

study also measured a higher emissions level of 16 g/yr for 26 vehicles in a hotter climate 

(Okinawa). This study indicated the leakage rate to be close to 8.6 g/yr for single evaporator 

systems and 13.3 g/yr for dual evaporator systems.11 A weighted (test) average gives 9.9 g/yr. 

In the second study, emissions were measured on European-market vehicles up to seven years 

age driven from November, 2002 to January, 2003.12 The European vehicle emission rates 

were slightly higher than the Japanese fleet, but overall, they were consistent. The average 

emission rate from this analysis is 17.0 g/yr with a standard deviation of 4.4 g/yr. European 

vehicles, because they have smaller charge sizes, likely understate the leakage rate relative to 

the United States. To these emission rates, the J2727 authors added a factor to account for 

occasional defective parts and/or improper assembly and to calibrate the result of the SAE 

J2727 calculation with the leakage measured in the vehicle and component leakage studies. 

We adjust this rate up slightly by a factor proportional to the average European 

refrigerant charge to the average United States charge (i.e. 770/747 from the Vintaging model 

and Schwarz studies respectively). The newer vehicle emission rate is thus 18 g/yr for the 

average newer vehicle emissions. This number is a combined car and truck number, and 

although based on the limited data, it was not possible to separate them. 

To derive the minimum score, the 18 gram per year rate was used as a ratio to convert 

the gram per mile emission impact into a new vehicle gram per year for the test. The car or 

truck direct a/c emission factor (gram per mile) was divided by the average emission factor 

(gram per mile) and then multiplied by the new vehicle average leakage rate (gram per year) 

Equation 2 – J2727 Minimum Score 

J2727 Minumum Score = Car or truck average pre control emissions (gram per 

mile)/ Fleet average pre-control emissions (grams per mile) x New vehicle annual 

leakage rate (grams per year) x Minimum Fraction 

By applying this equation, the minimum J2727 score is fixed at 8.3 g/yr for cars and 

10.4 g/yr for trucks. This corresponds to a total fleet average of 18 grams per year, with a 

maximum reduction fraction of 50% 

The GWP Refrigerant term in Equation 1 allows for the accounting of refrigerants 

with lower GWP (so that this term can be as low as zero in the equation), which is why the 

same minimum score is kept regardless of refrigerant used. 

It is technically feasible for the J2727 Minimum score to be less than the values 

presented in the table. But this will usually require the use of an electric compressor (see 

below for technology description), which the EPA does not expect to see with high 
Air Conditioning 

2-11 

penetrations within the 2012-2016 timeframe, as this technology is likely to accompany 

hybrid vehicle and stop-start technologies, and not conventional vehicles. 

2.2.2.2.3 AvgImpact Term 

AvgImpact is the average annual impact of A/C leakage, which is 16.6 and 20.7 g/yr 

for cars and trucks respectively. This was derived using Equation 2, but by setting the 

minimum fraction to one. 

2.2.2.2.4 GWPRefrigerant Term 

This term is relates to the global warming potential (GWP) of the refrigerant as 

documented by EPA. A full discussion of GWP and its derivation is too lengthy for this 

space, but can be found in many EPA documents.13 This term is used to correct for 

refrigerants with global warming potentials that differ from HFC-134a. As just explained, 

this term accounts for the GWP of any refrigerant used, and can be as low as zero. 

2.2.3 Technologies That Reduce Refrigerant Leakage and their Effectiveness 

In this section, the baseline technologies which were used in the EPA’s analysis of 

refrigerant leakage are described as well as the effectiveness of the leakage-reducing 

technologies that are believed will be available to manufacturers in the 2012-to-2016 

timeframe of this proposed rulemaking. An EPA analysis to determine a baseline leakage 

emission rate was conducted in the 2006-to-2007 timeframe, and at that time, it was estimated 

that the A/C system in new vehicles would leak refrigerant at an average rate of 18 g/yr, 

which represents the types of A/C components and technologies currently in use. EPA 

believes, through utilization of the leakage-reducing technologies described below, that it will 

be possible for manufacturers to reduce refrigerant leakage 50%, relative to the 18 g/yr 

baseline level.14 EPA also believes that all of these leakage-reducing technologies are 

currently available, and that many manufacturers have already begun using them to improve 

system reliability and in anticipation of the State of California’s Environmental Performance 

Label regulations and the State of Minnesota’s reporting requirements for High Global 

Warming Potential Gases. 

In describing the technologies below, only the relative effectiveness figures are 

presented, as the individual piece costs are not known. The EPA only has costs of complete 

systems based on the literature, and the individual technologies are described below. 

2.2.3.1 Baseline Technologies 

The baseline technologies assumed for A/C systems which have an average annual 

leak rate of 18 g/yr are common to many mass-produced vehicles in the United States. In 

these mass-produced vehicles, the need to maintain A/C system integrity (and the need to 

avoid the customer inconvenience of having their A/C system serviced due to loss of 

refrigerant) is often balanced against the cost of the individual A/C components. For 

manufacturers seeking improved system reliabilty, components and technologies which 

reduce leakage (and possibly increase cost) are selected, whereas other manufacturers may 
Draft Regulatory Impact Analysis 

2-12 

choose to emphasize lower system cost over reliabilty, and choose components or 

technologies prone to increased leakage. In the absence of standards or credits concerning 

refrigerant leakage, it is the market forces of cost and reliability which determine the 

technology a manufacturer chooses. In EPA’s baseline scenario, the following assumptions 

were made concerning the definition of a baseline A/C system: 

 all flexible hose material is rubber, without leakage-reducing barriers or 

veneers, of approximately 650 mm in length for both the high and low 

pressure lines 

 all system fittings and connections are sealed with a single o-rings 

 the compressor shaft seal is a single-lip design 

 one access port each on the high and low pressure lines 

 two of the following components: pressure switch, pressure relief 

valves, or pressure transducer 

 one thermostatic expansion valve (TXV) 

The design assumptions of EPA baseline scenario are also similar to the sample 

worksheet included in SAE’s surface vehicle standard J2727 – HFC-134a Mobile Air 

Conditioning System Refrigerant Emission Chart.15 In the J2727 emission chart, it is the 

baseline technologies which are assigned the highest leakage rates, and the inclusion of 

improved components and technologies in an A/C system will reduce this annual leakage rate, 

as a function of their effectiveness relative to the baseline. EPA considers these ‘baseline’ 

technologies to be representative of recent model year vehicles, which, on average, can 

experience a refrigerant loss of 18 g/yr. However, depending on the design of a particular 

vehicle’s A/C system (e.g. materials, length of flexible hoses, number of fittings and adaptor 

plates, etc.), it is possible to achieve a leakage score much higher (i.e. worse) than 18 g/yr. 

According to manufacturer data submitted to the State of Minnesota, 19% of 2009 model year 

vehicles have a J2727 refrigerant score greater than 18 g/yr, with the highest-scoring vehicle 

reporting a leakage rate of 30.1 g/yr.16 The average leakage was found to be 15.1 g/yr, 

though this value is not sales weighted. 

2.2.3.2 Flexible Hoses 

The flexible hoses on an automotive A/C system are needed to isolate the system from 

engine vibration and to allow for the engine to roll within its mounts as the vehicle accelerates 

and decelerates. Since the compressor is typically mounted to the engine, the lines going toand-from the compressor (i.e. the suction and pressure lines) must be flexible, or unwanted 

vibration would be transferred to the body of the vehicle (or other components), and excessive 

strain on the lines would result. It has been industry practice for many years to manufacture 

these hoses from rubber, which is relatively inexpensive and durable. However, rubber hoses 

are not impermeable, and refrigerant gases will eventually migrate into the atmosphere. To 

reduce permeation, two alternative hose material can be specified. The first material, is 

known as a standard ‘veneer’ (or ‘barrier’) hose, where a polyamide (polymer) layer - which 

has lower permeability than rubber - is encased by a rubber hose. The barrier hose is similar 

to a veneer hose, except that an additional layer of rubber is added inside the polyamide layer, 

creating three-layer hose (rubber-polyamide-rubber). The second material is known as ‘ultra-
Air Conditioning 

2-13 

low permeation’, and can be used in a veneer or barrier hose design. This ultra-low 

permeation hose is the most effective at reducing permeation, followed by the standard veneer 

or barrier hose. Permeation is most prevalent during high pressure conditions, thus it is even 

more important that these low permeable hoses are employed on the high pressure side, more 

so than on the low pressure side. EPA expects that many manufacturers will begin using 

these technologies (and many have already begun doing so) to reduce refrigerant leakage. 

According to J2727, standard barrier veneer hoses have 25% the permeation rate of 

rubber hose, and ultra low permeable barrier veneer hoses have 10% the permeation rate (as 

compared to a standard baseline rubber hose of the same length and diameter). 

2.2.3.3 System Fittings and Connections 

Within an automotive A/C system and the various components it contains (e.g. 

expansion valves, hoses, rigid lines, compressors, accumulators, heat exchangers, etc.), it is 

necessary that there be an interface, or connection, between these components. These 

interfaces may exists for design, manufacturing, assembly, or serviceability reasons, but all 

A/C systems have them to some degree, and each interface is a potential path for refrigerant 

leakage to the atmosphere. In SAE J2727 emission chart, these interfaces are described as 

fittings and connections, and each type of fitting or connection type is assigned an emission 

value based on its leakage potential; with a single o-ring (the baseline technology) having the 

highest leak potential; and a metal gasket having the lowest. In between these two extremes, 

a variety of sealing technologies, such as multiple o-rings, seal washers, and seal washers with 

o-rings, are available to manufacturers for the purpose of reducing leakage. It is expected that 

manufacturers will choose from among these sealing technology options to create an A/C 

system which offers the best cost-vs-leakage rate trade-off for their products. 

The relative effectiveness of the fitting and connector technology is presented in Table 

2-5. For example, the relative leakage factor of 125 for the baseline single O-ring is 125 

times more “leaky” than the best technology - the metal gasket. 

Table 2-5 : Effectiveness of Fitting and Connector Technology 

Fitting or Connector Relative 

Leakage 

Single O-ring 125

Single Captured O-ring 75

Multiple O-ring 50

Seal Washer 10

Seal Washer with O-ring 5

Metal Gasket 1
Draft Regulatory Impact Analysis 

2-14 

2.2.3.4 Compressor Shaft Seal 

A major source of refrigerant leakage in automotive A/C systems is the compressor 

shaft seal. This seal is needed to prevent pressurized refrigerant gasses from escaping the 

compressor housing. As the load on the A/C system increases, so does the pressure, and the 

leakage past the seal increases as well. In addition, with a belt-driven A/C compressor, a side 

load is placed on the compressor shaft by the belt, which can cause the shaft to deflect 

slightly. The compressor shaft seal must have adequate flexibility to compensate for this 

deflection, or movement, of the compressor shaft to ensure that the high-pressure refrigerant 

does not leak past the seal lip and into the atmosphere. When a compressor is static (not 

running), not only are the system pressures lower, the only side load on the compressor shaft 

is that from tension on the belt, and leakage past the compressor shaft is at a minimum. 

However, when the compressor is running, the system pressure is higher and the side load on 

the compressor shaft is higher (i.e. the side load is proportional to the power required to turn 

the compressor shaft) - both of which can increase refrigerant leakage past the compressor 

shaft seal. It is estimated that the rate of refrigerant leakage when a compressor is running 

can be 20 times that of a static condition.7

 Due to the higher leakage rate under running 

conditions, SAE J2727 assigns a higher level of impact to the compressor shaft seal. In the 

example shown in the August 2008 version of the J2727 document, the compressor is 

responsible for 58% of the system refrigerant leakage, and of that 58%, over half of that 

leakage is due to the shaft seal alone (the remainder comes from compressor housing and 

adaptor plate seals). To address refrigerant leakage past the compressor shaft, manufacturers 

can use multiple-lip seals in place of the single-lip seals. 

2.2.4 Technical Feasibility of Leakage-Reducing Technologies 

EPA believes that the leakage-reducing technologies discussed in the previous 

sections are available to manufacturers today, are relatively low in cost, and that their 

feasibility and effectiveness have been demonstrated by the SAE IMAC teams. EPA also 

believes – as has been demonstrated in the J2727 calculations submitted by manufacturers to 

the State of Minnesota – that reductions in leakage from 18 g/yr to 9 g/yr are possible (e.g. the 

2009 Saturn Vue has a reported leakage score of 8.5 g/yr). In addition to earning credit for 

reduced refrigerant leakage, some manufacturers may, within the timeframe of this 

rulemaking, choose to introduce alternative refrigerant systems, such as HFO-1234yf. 

2.2.5 Deterioration of Leakage Controls in A/C Systems 

In order to determine the cost savings from the improvements to the leakage system, it 

is necessary to project the point at which the vehicle will require servicing and an additional 

refrigerant charge. 

There are two mechanisms of deterioration that are modeled: the normal deterioration 

that results in increasing leakage and the “avoidable” deterioration of the condenser & 

compressor components. This model is developed to help us estimate the costs of the A/C 
Air Conditioning 

2-15 

reductions. It is especially needed to determine the period over which the discounted cost 

savings should be applied.E

 

Normal deterioration occurs throughout all components of the A/C system. Hoses, 

fittings, compressors, etc all wear with age and exposure to heat (temperature changes), 

vibration, and the elements. It is assumed that the system deterioration rates decrease 

(proportionally) as the base leakage rates are decreased with the use of improved parts and 

components. The base deterioration rate is modeled as a linear function, such that the (new 

vehicle) leakage rate is 18 g/yr at age zero and 59 g/yr at the “average” age of 5 years old. 

The 18 gram leakage rate for new vehicles has been documented in section 2.2.2, while the 59 

gram mid-life leakage rate is drawn from the Vintaging model and is documented below. 

The Vintaging model assumes a constant leakage + servicing emission rate of 18% per 

year for modern vehicles running with HFC-134a refrigerant. As the emission rates do not 

change by age in vintaging, the emission rate is the average rate of loss over the vehicle’s life. 

 Applying the percentages in Table 2-2, this corresponds to a leakage rate of 7.6% (59 

grams) per year and a servicing loss rate of 8.8% (68 grams) per year averaged over the 

vehicle’s life. The model assumes an average refrigerant charge of 770 grams for vehicles 

sold in 2002 or later and does not currently assume that these charge sizes will change in the 

future; however, the model may be updated as new information becomes available. The 

resulting vehicle emission rates are presented in Table 2-6. 

Table 2-6: Annual in-use vehicle HFC-134a emission rate from Vintaging model. 

Emission Process Leak rate (%/year) Leak rate (g/year) 

Leakage 7.6% 59 

Servicing/maintenance 8.8% 68 

The average leakage emissions rate of 59-68 g/yr is higher with Schwarz’s European2

study and lower than CARB’s study,3

 and thus is within the range of results in the literature. 

 

E Air conditioning leakage controls are the only technology in this proposed rule that has an 

assumed deterioration that affects the effectiveness of the technology. This is partly because sufficient 

data is not available for many of the technologies in chapter 3 of the TSD. Moreover, it is not 

expected that deterioration of powertrain technologies will lead to emissions increases on the scale of 

those seen when criteria pollutant technologies deteriorate. The deterioration from the latter can 

increase emissions by factors of 10 or even 100 or more. Similarly, air conditioning leakage 

technologies can and do deteriorate, contributing to significantly higher emissions over time. For this 

reason, a deterioration model is proposed below. This model only applies for leakage, and not for 

indirect CO2 (tailpipe) emissions due to A/C. For the latter, a partly functioning system may lead to 

somewhat higher emissions, but when it finally fails, it is one of the few technologies where the 

emissions are no longer relevant, i.e. an A/C system that no longer functions, no longer emits indirect 

emissions. 
Draft Regulatory Impact Analysis 

2-16 

This model is presented in Figure 2-1 with the assumption that the average vehicle 

(A/C system) last about 10 years. Technically, the assumption is that the A/C system lasts 10 

years and not the vehicle per se. Inherent in this assumption is that the vehicle owner will not 

repair the A/C system on an older vehicle due to the expensive nature of most A/C repairs late 

in life relative to the value of the vehicle. It is also assumed that the refrigerant requires a 

recharge when the state of charge reaches 50% for the analysis in this section. This 

deterioration/leakage model approach will be used later to estimate the cost of maintenance 

savings due to low leak technologies (from refills) as well as the benefits of leakage controls. 

0

20

40

60

80

100

120

0 2 4 6 8 10 12

Age (years)

Leakage Emissions (g/yr)

0

100

200

300

400

500

600

700

800

charge remaining (grams)

leakage

remaining charge

recharge 

required

Figure 2-1. Deterioration rate of refrigerant leakage. 

Figure 2-2 shows how the leakage rates vary with age as the initial leakage rates are 

decreased to meet new proposed standards (with improved components and parts). The 

deterioration lines of the lower leakage rates were determined by applying the appropriate 

ratio to the 17 g/yr base deterioration rate. Figure 2-3 shows the refrigerant remaining, which 

includes a line indicating when a recharge is required (50% charge remaining out of an initial 

charge of 770g). So a typical vehicle meeting a leakage score of 8.5 g/yr (new) will not 

require a recharge until it is about 12 years old. 
Air Conditioning 

2-17 

0

20

40

60

80

100

120

0 2 4 6 8 10 12 14

Age of Vehicle

Leakage (g/yr)

18 g/yr

13.5 g/yr

9 g/yr

4.5 g/yr

Figure 2-2. A/C refrigerant leakage rate for different technologies as vehicles age. 

0

100

200

300

400

500

600

700

800

0 2 4 6 8 10 12 14

Age (years)

Refrigerant Remaining (grams)

18 g/yr

13.5 g/yr

9 g/yr

4.5 g/yr

refill line
Draft Regulatory Impact Analysis 

2-18 

Figure 2-3. A/C refrigerant remaining in a typical system as vehicles age and deteriorate. 

2.2.6 Other Benefits of improving A/C Leakage Performance 

The EPA is assuming that a reduction in leakage emissions from new vehicles will 

also improve the leakage over the lifetime of the vehicle. There is ample evidence to show 

that A/C systems that leak more also have other problems that occur (especially with the 

compressor) due to the lack of oil circulating in the system. Thus, it is expected that an A/C 

system which utilizes leak-reducing components and technologies should, on average, last 

longer than one which does not. 

An European study conducted in 2001 (by Schwarz) found that the condenser is the 

component most likely to fail and result in a total leak.17 The study also found that 

compressor component was most likely the culprit when other malfunctions were present 

(other than total loss). A more recent (and larger) study found that condensers required 

replacement at half the rate of a compressor (10% vs 19% of the entire part replacement rate), 

and that evaporators and accumulators failed more often.7

 The same study also found that 

many of the repairs occurred when the vehicles were aged 5-10 years. Both these studies 

indicate that the condenser and compressor are among the major causes of failure in an A/C 

system. Leakage reductions in the system are expected to greatly reduce the incidence of 

compressor repair, since one of the main root causes of compressor failure is a shortage of 

lubricating oil, which originates from a shortage of refrigerant flowing through the system 

(and it is a refrigerant-oil mixture which carries lubricating oil to the compressor).18

Monitoring of refrigerant volume throughout the life of the A/C system may provide 

an opportunity to circumvent some previously described failures specifically related to 

refrigerant loss. Similar to approaches used today by the engine on-board diagnostic systems 

(OBD) to monitor engine emissions, a monitoring system that informed the vehicle operator 

of a low refrigerant level could potentially result in significant reductions in A/C refrigerant 

emissions due to component failure(s) by creating an opportunity for early repair actions. 

While most A/C systems contain sensors capable of detecting the low refrigerant pressures 

which result from significant refrigerant loss, these systems are generally not designed to 

inform the vehicle operator of the refrigerant loss, and that further operation of the system in 

this state can result in additional component damage (e.g. compressor failure). Electronic 

monitoring of the refrigerant may be achieved by using a combination of existing A/C system 

sensors and new software designed to detect refrigerant loss before it progresses to a level 

where component failure is likely to occur. 
Air Conditioning 

2-19 

2.3 CO2 Emissions due to Air Conditioners 

2.3.1 Impact of Air Conditioning Use on Fuel Consumption and CO2 Emissions 

Three studies have been performed in recent years which estimate the impact of A/C 

use on the fuel consumption of motor vehicles. In the first study, the National Renewable 

Energy Laboratory (NREL) and the Office of Atmospheric Programs (OAP) within EPA have 

performed a series of A/C related fuel use studies.19,20 The energy needed to operate the A/C 

compressor under a range of load and ambient conditions was based on testing performed by 

Delphi, an A/C system supplier. They used a vehicle simulation model, ADVISOR, to 

convert these loads to fuel use over the EPA’s FTP test cycle. They developed a personal 

“thermal comfort”-based model to predict the percentage of drivers which will turn on their 

A/C systems under various ambient conditions. Overall, NREL estimated A/C use to 

represent 5.5% of car and light truck fuel consumption in the U.S. 

In the second study, the California Air Resources Board (ARB) estimated the impact 

of A/C use on fuel consumption as part of their GHG emission rulemaking.21 The primary 

technical analysis utilized by ARB is summarized in a report published by NESCCAF for 

ARB. The bulk of the technical work was performed by two contractors: AVL Powertrain 

Engineering and Meszler Engineering Services. This work is founded on that performed by 

NREL-OAP. Meszler used the same Delphi testing to estimate the load of the A/C 

compressor at typical ambient conditions. The impact of this load on onroad fuel 

consumption was estimated using a vehicle simulation model developed by AVL - the 

CRUISE model - which is more sophisticated than ADVISOR. These estimates were made 

for both the EPA FTP and HFET test cycles. (This is the combination of test cycle results 

used to determine compliance with NHTSA’s current CAFE standards.) NREL’s thermal 

comfort model was used to predict A/C system use in various states and seasons. 

The NESCAFF results were taken from Table 3-1 of their report and are summarized 

in Table 2-7.22

Table 2-7: CO2 Emissions Over 55/45 FTP/HFET Tests and From A/C Use (g/mi) 

Small Car Large Car Minivan Small Truck Large Truck 

55/45 FTP/HFET 278 329 376 426 493 

Indirect A/C Fuel Use 16.8 19.1 23.5 23.5 23.5 

Total 294.8 348.1 399.5 449.5 516.5 

Indirect A/C Fuel Use 5.7% 5.5% 5.9% 5.2% 4.6% 

NESCAFF estimated that nationwide, the average impact of A/C use on vehicle fuel 

consumption ranged from 4.6% for a large truck or SUV, to 5.9% for a minivan. The total 
Draft Regulatory Impact Analysis 

2-20 

CO2 emissions were determined using a 55%/45% weighting of CO2 emissions from EPA 

FTP and HFET tests plus A/C fuel use (hereafter referred to simply as FTP/HFET). .For the 

purposes of this analysis of A/C system fuel use, the percentage of CO2 emissions and fuel 

use are equivalent, since the type of fuel being used is always gasoline.F

 

In order to compare the NESCCAF and ARB estimates to that of NREL-OAP, 

weighting factors for the five vehicle classes were developed. NESCCAF presented sales 

percentages for the five vehicle classes in Table 2-1 of their report.22 These are shown below 

in Table 2-8. Since these sales percentages do not sum to 100% (possibly due to round-off or 

because some vehicles do not fit into any of the five categories) the percentages were 

normalized so that they summed to 100%. The car and truck categories were then weighted 

by their lifetime VMT, normalized to that of cars. G This meant a relative weighting factor for 

the three truck categories of 1.11 relative to a factor of 1.0 for cars. The percentage of 

lifetime VMT represented by each vehicle class were then determined. These estimates are 

shown on the last line of Table 2-8. 

Table 2-8: Sales and VMT by Vehicle Class 

Small Car Large Car Minivan Small Truck Large Truck 

NESCCAF sales 22% 25% 7% 23% 21% 

Normalized 

NESCCAF sales 22.4% 25.5% 7.1% 23.5% 21.4% 

Lifetime VMT 

weighting factor 1.00 1.00 1.11 1.11 1.11 

VMT 21.2% 24.1% 7.5% 24.6% 22.5% 

 Using the percentages of VMT represented by each vehicle class, the A/C fuel use 

impacts of NESCCAF and ARB were weighted and determined that they represent 5.3% and 

4.2% of fuel use over the FTP/HFET, respectively, including the A/C fuel use. 

In the final study, EPA evaluated the impact of A/C use on fuel consumption as part of 

its recent rulemaking which revised the onroad fuel economy labeling procedures for new 

motor vehicles.23 EPA estimated the impact of the A/C compressor on fuel consumption from 

vehicle emission measurements taken over its SC03 emissions test. SC03 is a 10 minute test 

where the vehicle is operated at city speeds, at 95 degrees F, 40% relative humidity and a 

solar load of 850 Watts/m2

. In addition, prior to the test, the vehicle has been pre-heated for 

 F

 Because NESCCAF estimated A/C fuel use nationwide, while ARB focused on that in California, the 

NESCCAF and EPA methodologies and results are coempared below. 

G Based on annual mileage per vehicle from the Volpe Model discounted at 7% per year. Discounted lifetime 

mileages are 102,838 for cars and 114,350 for trucks. 
Air Conditioning 

2-21 

10 minutes under these conditions, so the interior cabin starts the test at an elevated 

temperature. Testing of 500 late model vehicles over both the FTP and SC03 test cycles 

indicated that fuel consumption was 27% higher on the SC03 test than over a combination of 

Bag 2 and Bag 3 fuel consumption designed to match the vehicle load of the SC03 test. EPA 

assumed that the A/C compressor was engaged 100% of the time over SC03 due to the high 

ambient temperature, short duration and vehicle pre-heating test conditions. 

EPA does not measure A/C emissions at highway speeds. Thus, this impact had to be 

estimated based on the city-like SC03 test. EPA tested six vehicles (four conventional and 

two hybrid) over the FTP, SC03, and HFET emission tests in a standard test cell at 60 F, 75 F, 

and 95 F with and without the A/C system operating in order to assess the relative impact of 

A/C use at city and highway speeds. The data indicated that it was more accurate to assume 

that the impact of the A/C compressor on fuel consumption was the same at city and highway 

speeds when compared in terms of fuel burned per unit time than when compared in terms of 

fuel use per mile. Thus, EPA estimated the impact of A/C in terms of fuel use per mile at 

highway speeds by multiplying the A/C related fuel use at city speeds by the ratio of the speed 

of the city test to that of the highway test. For average driving in the U.S., this ratio was 

estimated to be 0.348. The result was that the impact of engaging the A/C compressor 100% 

of the time at highway speeds increased fuel use by 9.7%, versus 27% at city speeds. These 

percentages are based on the assumptions that fuel is only consumed during warmed up 

driving, hence ignoring cold start fuel use. 

EPA’s estimate in the Fuel Economy Labeling rule of in-use A/C compressor 

engagement was based on a test program covering 1004 trips made by 19 vehicles being 

operated by their owners in Phoenix, Arizona.24 The results of this testing were correlated 

against heat index, a function of temperature and humidity, and time of day, to represent solar 

load. Nationwide, EPA estimated that the A/C compressor was engaged 15.2% of the time. 

However, much of this time, the ambient conditions are less severe than those of the SC03 

test. Therefore, EPA reduced this percentage to 13.3% to normalize usage to the load 

experienced during SC03 conditions. On a nationwide basis, EPA estimated that the A/C 

system was turned on an average of 23.9% of the time.25 Resulting in 14.3 g/mi per vehicle 

CO2-equivalent impact due to A/C use (where 30% of the vehicle fleet is equipped with 

automatic A/C controls, and 70% of the fleet is equipped with manual controls).H

This estimate does not include defroster usage, while the NREL-OAP and ARBNESCCAF estimates do include this. EPA considered adding the impact of defroster usage 

based in large part on NREL-OAP estimates. NREL-OAP estimates that the defroster is in–

use 5.4% of the time. However, the load of the compressor under defrosting conditions is 

very low. EPA estimated that including defroster usage would increase the percentage of time 

that the compressor was engaged at a load equivalent to that over SC03 from 13.3% to 13.7%. 

While this defroster impact was quantified, EPA decided not to include it in its final 5-cycle 

 H Fraction of fleet equipped with automatic A/C control is based on is based on industry estimates and an EPA 

analysis of the percentage of 2008 U.S. car sales – as published in the 2009 Ward’s Automotive Yearbook - for 

vehicle categories likely to be equipped with automatic A/C (e.g. middle luxury car, specialty, middle luxury 

SUV, large luxury SUV, et. al.) 
Draft Regulatory Impact Analysis 

2-22 

fuel economy formulae. Based on the A/C usage factor of 13.3% and EPA’s 5-cycle 

formulae, A/C system use increases onroad fuel consumption by 2.4%. Including defroster 

use modestly increased this value to 2.5%. 

Comparing the results of the three studies, the EPA estimate gives the smallest A/C 

system impact, while the NREL-OAP estimate is the highest. The NESCCAF and NRELOAP studies give very similar results. The overall difference between the estimates is more 

than a factor of two. 

It is difficult to directly compare the three estimates. The NREL-OAP and ARBNESCCAF methodologies are very similar. However, the EPA methodology is quite 

different, as will be discussed further below. This complicates the comparison, making it 

difficult to compare smaller segments of each study directly. In addition, as will be seen, each 

study utilizes assumptions or estimates which contain uncertainties. These uncertainties are 

not well characterized. EPA concluded that it is not possible to determine a single best 

estimate of A/C fuel use from these studies. However, EPA was able to identify a couple of 

aspects of the studies which could be improved for the purpose of this analysis. Doing so, the 

overall difference between the studies was reduced by roughly one half. This process is 

described below. 

The first step in this comparison will reduce the number of studies from three to two. 

The NREL-OAP and ARB-NESCCAF methodologies are very similar, since both utilize the 

NREL-OAP comfort model to estimate A/C usage onroad. They also both use essentially the 

same estimate of A/C compressor load from Delphi to estimate the load which the compressor 

puts on the engine. ARB-NESCCAF utilized the vehicle simulation tool, AVL’s CRUISE 

model, to estimate the impact of A/C load on fuel economy, while NREL employed the 

ADVISOR model (both models assumed a rather simple A/C system load). In addition, 

ARB-NESCCAF modeled both city and highway driving (i.e., the 55/45 FTP/HFET), while 

NREL-OAP only modeled the FTP. Thus, EPA will focus on the NESCCAF estimate over 

that of NREL-OAP, though as mentioned above, their overall estimates are very similar. 

Also, because NESCCAF estimated A/C fuel use nationwide, while ARB focused on that in 

California, EPA will focus on comparing the NESCCAF and EPA methodologies and results 

below. With respect to EPA’s estimates from the 2006 rulemaking, the estimate including 

defroster use will be used, since NESCCAF considered defroster use, as well. As way of 

reminder, on a nationwide average basis, the NESCAFF estimates indicate that A/C use 

represents 5.3% of total fuel consumption, while EPA estimates this at 2.5%. 

NESCCAF and EPA break down the factors which determine the impact of A/C use 

on onroad fuel consumption differently. NESCCAF breaks down the process into three parts. 

The first is the frequency that drivers turn on their A/C system. The second is the average 

load of the A/C compressor at various ambient conditions, including compressor cycling. The 

third is the impact of this average A/C compressor load on fuel economy over various driving 

conditions. 

In contrast, in the fuel labeling rulemaking, EPA breaks down the process into two 

parts. The first is the frequency that the A/C compressor is engaged at various ambient 

conditions. This includes both the frequency that the driver turns on the A/C unit and the 
Air Conditioning 

2-23 

frequency that the compressor is engaged when the system is turned on. The second is the 

impact of the A/C compressor on fuel economy over various driving conditions when the 

compressor is engaged. 

The most direct comparison that can be made between the two studies is the estimate 

of A/C system use. Because EPA measured both A/C system on/off condition as well as 

compressor engaged/disengaged condition in the Phoenix test program, it is possible to 

compare the percentage of A/C system use as measured in the Phoenix study and extrapolated 

to the U.S. to that of the NREL-OAP comfort model. 

In its rulemaking analysis, based on its Phoenix study and extrapolation procedure, 

EPA estimated that on average, the A/C unit was turned on 23.9% of the time. This does not 

include defroster use. There, EPA also determined that the NREL-OAP thermal comfort 

model predicts a higher percentage of 29%, again ignoring defroster use. Since EPA utilized 

NREL-OAP’s estimate of defroster use in its analysis, this estimate does not contribute to the 

difference in the two estimates. Also, fuel use is very low during defroster use compared to 

air conditioning at high ambient temperatures, so the difference between the 23.9% and 29% 

estimates is the most relevant factor. By itself (ignoring fuel use during defrosting), this 

difference would cause the NESCCAF A/C fuel use estimate to be 27% higher than that of 

EPA. The overall difference between the 5.3% and 2.5% estimates is 112%. Thus, the 

difference in estimated A/C system use explains about one-fourth of the overall difference 

between the two studies. 

NREL’s thermal comfort model for vehicle A/C use is based on a model designed to 

the represent the comfort of a person walking outside and wearing one of two different sets of 

clothes. A number of assumptions had to be made in order to extrapolate this outdoor model 

to a person sitting in a vehicle. The predictions of NREL-OAP’s thermal comfort model have 

not been confirmed with any vehicle/occupant testing and their air conditioner settings. 

Therefore, its predictions, while reasonable, are of an unknown accuracy. 

EPA’s Phoenix study was performed over a relatively short period of time, roughly 

seven weeks. It was conducted in only one city, Phoenix. Thus, the variation in climate 

evaluated was limited. The number of vehicles tested was also fairly small, nineteen. 

However, over 1000 trips were monitored by these 19 vehicles. EPA extrapolated the 

measured A/C compressor engagement under these limited ambient conditions to other 

conditions using a metric called the heat index, which combines temperature and humidity 

into a single metric. Heat index is conceptually similar to NREL-OAP’s comfort model. This 

allowed the results found in the generally dry climate of Phoenix to be extrapolated to both 

cooler and more humid conditions typical of the rest of the U.S. No testing has yet been 

performed to confirm the accuracy of this extrapolation. 

Given the two very different approaches to estimating vehicle A/C system use, it is 

notable that the difference in the two estimates is only a relative 27%. As both the EPA and 

NREL-OAP models of A/C system use involve assumptions or extrapolations which have not 

been verified, it is not possible to determine which one is more accurate. Thus, the 

differences in the EPA and ARB estimates of the impact of A/C use on onroad fuel 

consumption due to these two different sources of A/C usage cannot be resolved at this time. 
Draft Regulatory Impact Analysis 

2-24 

With respect to the operation of the A/C compressor at various ambient and driving 

conditions, EPA bases its estimate on the Phoenix vehicle test study. This is subject to the 

same uncertainties described above, due mainly to the limited scope of the data. NREL-OAP 

relies on test results published by W.O. Forrest of Delphi. Forrest describes the factors which 

affect the load of the A/C system on the engine: the percentage of time the compressor is 

engaged, compressor displacement, compressor speed, air flow across the evaporator, engine 

operating condition and ambient conditions. The load curves presented by Forrest apply to a 

210 cc compressor and show load as a function of compressor speed for six sets of ambient 

conditions. The loads include the effect of compressor cycling. However, no mention is 

made of airflow rates across the evaporator, which would vary with engine speed. It is not 

clear whether these curves were based on bench testing or onroad vehicle testing. Also, only 

one A/C system appears to have been tested. It is not clear how well these curves would 

apply to other manufacturers’ systems, nor even to others produced by Delphi. Forrest states 

that the loads for other compressor displacements can be approximated by assuming that the 

load is proportional to compressor displacement. However, this is clearly an approximation 

and does not address differences inherent in particular A/C system applications. The fact that 

the NESCCAF analysis is based on the testing of only a single A/C system and does not 

address the effect of varying airflow rates under different driving conditions appears to be the 

largest sources of uncertainty in their estimate. 

It is not possible to directly compare these two estimates of compressor operation. 

EPA’s Phoenix study provides an estimate of the percentage of time that the compressor is 

engaged when the A/C system is on. On the other hand, compressor cycling is implicitly 

included in the Delphi load curves. Since the load curves of a continuous operating 

compressor were not presented, the degree of cycling cannot be determined. Thus, the effect 

of any differences in the NESCCAF and EPA estimates of compressor engagement cannot be 

quantified. 

With respect to the impact of the A/C compressor load on fuel economy, EPA relies 

on a comparison of measured fuel economy over the two warmed up bags of its FTP test 

(when the A/C system is inoperative) and its SC03, A/C emissions test. The vehicles on both 

tests are run at city speeds. EPA based its estimates on the testing of over 600 recent model 

year vehicles. Thus, for the conditions addressed by the SC03 test, EPA’s estimate of the 

impact of A/C system load on fuel economy is well supported. However, in order to combine 

this measurement with the Phoenix study, EPA needed an estimate of the percentage of time 

that the compressor was engaged during the SC03 test. The SC03 test does not include a 

measurement of this factor, so EPA had to estimate the percentage of time that the compressor 

was engaged during the test. As noted above, EPA assumed that the A/C compressor was 

engaged 100% of the time during the SC03 test given its short duration and the pre-heating of 

the vehicle. Thus, for a given ambient condition, if the compressor was estimated to be 

engaged 25% of the time, then the incremental amount of fuel used due to A/C system was 

25% of the difference between the fuel use over the SC03 test and a 39%/61% weighting of 

the fuel use over Bags 2 and 3 of the FTP, respectively. 

EPA has evidence to show that most vehicles’ A/C compressors are engaged 100% of 

the time over SC03.26 The vehicle pre-heating, short test duration and the requirement that 

the driver window be rolled down, make it extremely likely that the vehicle compartment 
Air Conditioning 

2-25 

never reaches a comfortable temperature by the end of the test. However, it is possible that 

the compressor still cycled to some degree during the test. All compressors shut down when 

the heat exchanger nears 32 F in order to avoid icing. The cold heat exchanger continues to 

cool the refrigerant while the compressor is shut down, but the compressor is not putting an 

additional load on the engine and increasing fuel consumption. As it is impossible for the 

compressor to operate more than 100% of the time, any error in EPA’s assumption can only 

lower the actual compressor use below 100%. If compressor engagement was lower than 

100%, this would mean that fuel use at 100% compressor engagement would be higher than 

currently estimated. Thus, it is possible that this assumption that the A/C compressor is 

engaged 100% during SC03 is causing EPA’s estimate of A/C fuel use to be under-estimated 

to some degree. 

There are additional uncertainties involved in EPA’s assumption that a vehicle’s A/C 

fuel use is constant in terms of gallons per hour, and thus inversely proportional to vehicle 

speed when presented in terms of gallons per mile. EPA testing of six vehicles as part of the 

Fuel Economy Labeling rulemaking (used to estimate A/C compressor usage in highway 

driving conditions, as noted above) confirmed that A/C fuel use was roughly constant in terms 

of gallons per hour. However, this testing was performed in a standard emission test cell. Air 

flow through the engine compartment was the same at city and highway speeds. The city test 

was only 20 minutes long and the highway test was only 10 minutes long. There was also 

significant variability in the individual vehicle test results. Thus, while the testing showed 

that EPA’s assumption was reasonable, there is an unknown degree of uncertainty associated 

with extrapolating the measured A/C fuel use at city speeds to highway speeds. One could 

attempt to quantify the uncertainty using the test results of the six vehicles. However, these 

vehicles were not randomly selected and two of the six vehicles were Prius hybrids. Thus, it 

is not clear how representative the results of a statistical analysis of these data would be. 

An A/C load adjustment factor is also applied to account for the change in compressor 

load which occurs when the compressor is engaged at different temperatures. The study 

which developed this data data is based on an A/C model developed by Nam (2000).27

NESCCAF starts with A/C compressor load curves which describe the A/C 

compressor load as a function of compressor speed for six ambient conditions. These curves, 

along with A/C - on percentages from the thermal comfort model, were used to interpolate 

between the six compressor load curves to estimate the load curves applicable to the ambient 

conditions existing during driving times for a large number of cities across the U.S. The 

resulting curves are averaged using the VMT estimated to occur in each city to produce a 

single load curve representing the entire U.S. 

NESCCAF then input this national average load curve into AVL’s CRUISE model to 

estimate the effect of A/C on fuel consumption over the FTP and HFET cycles. The CRUISE 

model simulates vehicle operation and fuel consumption over specified driving conditions. 

The load of the A/C compressor (based on bench testing) was added to the other loads being 

placed on the vehicle, such as inertia, friction, aerodynamic drag, etc. The A/C loads included 

the cycling of the compressor as a function of ambient condition. In actuality, the engine will 

experience the full load of the compressor at some times and no load at other times. This 

could produce a slightly different fuel use impact than applying the average load of the 
Draft Regulatory Impact Analysis 

2-26 

compressor all of the time. However, this error is likely very small. The A/C load curves 

vary as a function of engine speed, but not vehicle speed. However, as air flow by the heat 

exchanger will vary as a function of vehicle speed, compressor cycling and evaporator 

cooling efficiency is likely to vary, as well. However, the degree of error associated with any 

of these simplifications is unknown. 

A detailed comparison of this aspect of the two analyses would require reconstructing 

both models to produce A/C fuel use estimates for specific ambient conditions. This is 

beyond the scope of the study. Also, once the differences were known, it would still be 

difficult to decide which estimate was superior. 

There is one aspect of each analysis which appears to be an improvement over the 

other. In addition to A/C, EPA evaluated a number of other reasons why onroad fuel 

economy differs from that measured over the FTP and HFET cycles. Among these were 

higher speed and more aggressive driving, ambient temperatures below 75 F, short trips, 

wind, under-inflated tires, ethanol containing fuel, etc. This does not affect the absolute 

volume of fuel used by the A/C system, but it does raise the total amount of fuel consumed 

onroad, effectively lowering the percentage of fuel due to A/C use. 

NESCCAF estimated the impact of the A/C compressor load on fuel use during city 

and highway driving using the CRUISE model. While it is not clear that this is superior to 

EPA’s SC03 data, the CRUISE model is likely more accurate for highway driving than an 

extrapolation of the SC03 data (i.e. EPA’s six vehicle study described above). While 

CRUISE was not able to represent all aspects of vehicle operation, such as airflow across the 

evaporator, it does simulate the difference in engine speed and load between city and highway 

driving. This allows a detailed simulation of the A/C compressor speed during this driving, 

which is a primary factor in estimating A/C compressor load. EPA’s extrapolation of the 

impact over SC03 essentially assumes that engine speed and airflow over the evaporator are 

the same during both city and highway driving, or that any differences cancel each other. 

This is unlikely. Therefore, NESCCAF’s highway estimates are likely more accurate than 

EPA’s. 

Since the two analyses were performed so differently, the CRUISE results for highway 

driving cannot be simply substituted for EPA’s estimates. However, one way to utilize the 

CRUISE highway results is to determine the ratio of the impact of the A/C load on fuel use 

over the HFET to that over the FTP. This ratio can then be substituted for EPA’s assumption 

that the impact of A/C load is constant with time (inversely proportional to vehicle speed in 

terms of gallons per mile. 

Adjusting the NESCCAF estimates for the other factors reducing onroad fuel economy 

relative to the FTP/HFET is straightforward. EPA found that all such factors, including A/C, 

reduced onroad fuel economy to 80% of the FTP/HFET. In other words, onroad fuel 

consumption is 25% higher (1/0.8) than over the FTP/HFET. Thus, the CO2 emissions over 

the FTP/HFET shown above in Table 2-7 are multiplied by a factor of 1.25 to represent 

onroad CO2 emissions. A/C fuel use is unaffected. A/C fuel use as a percentage of onroad 

fuel use is simply the ratio of the A/C fuel use divided by the estimated onroad fuel use. 
Air Conditioning 

2-27 

These figures are shown in Table 2-9 below. The VMT weighted average of these 

percentages is 4.4%, 0.9% lower than the estimate presented above. 

Table 2-9: Adjusted NESCCAF CO2 Emissions Over 55/45 FTP/HFET Tests and From A/C Use 

(g/mi) 

 Small Car Large Car Minivan Small Truck Large Truck 

55/45 FTP/HFET 349 413 472 535 619 

Indirect A/C Fuel Use 16.8 19.1 23.5 23.5 23.5 

Indirect A/C Fuel Use 4.8% 4.6% 5.0% 4.4% 3.8% 

Incorporating the relative impact of A/C load on fuel consumed over the HFET versus 

FTP cycles from CRUISE requires a few steps. Table 2-10 shows the incremental CO2

emissions from the A/C compressor load from the CRUISE simulations of the FTP and HFET 

cycles. The top half of the table shows the incremental fuel use in terms of grams CO2 per 

mile. These figures were taken from Tables B-20 through B-23 of the NESCCAF report.28 

For the large car, two base vehicles were simulated. EPA selected the vehicle with the 

conventional gasoline engine with variable valve timing and lift. The large truck was not 

modeled using CRUISE. Further in the study, Meszler assumed that the A/C fuel impact was 

proportional to compressor displacement. The large truck is assumed to have the same 

compressor displacement as the minivan and small truck. Thus, the A/C fuel impact was 

estimated for the large truck as the average of the impacts for the minivan and small truck. 

The bottom half of the table shows the incremental fuel use in terms of grams CO2 per 

minute. These figures were calculated by multiplying the A/C fuel impacts in grams per mile 

by the average speeds of the FTP and HFET cycles: 19.6 and 48.2 mph and converting hours 

to minutes. The final line of the table shows the ratio of the incremental fuel use in terms of 

grams CO2 per minute for the HFET cycle to that over the FTP. 

Table 2-10: Impact of A/C on Fuel Use: System 

 Small Car Large Car Minivan Small Truck Large Truck 

A/C impact: 100% A/C System On Time (g/mi) 

FTP 67.4 56.6 81.8 89.7 85.8 

HFET 32.3 31.9 45.0 47.4 46.2 

A/C impact: 100% A/C System On Time (g/minute (g/min)) 

FTP 22.02 18.49 26.7 29.3 28.0 

HFET 25.95 25.63 36.2 38.1 37.1 

HFET/FTP (g/min)/(g/min) 1.18 1.39 1.35 1.30 1.32 

As can be seen in the last line of Table 2-10, the ratio of A/C CO2 emissions over the 

HFET to that over the FTP is greater than 1.0 for each of the five vehicles. VMT weighting 

the CO2 emissions for each of the five vehicle groups produces an average ratio of 1.30. EPA 

assumed that this ratio was 1.0. Thus, EPA likely underestimated the impact of A/C fuel use 

during highway driving by 30%. For the purposes of EPA’s onroad fuel economy labeling 

rule, this under-estimation is small, because the impact of A/C on highway fuel economy is 

small. However, when estimating the impact of A/C fuel use, the difference is more 

significant. EPA’s five cycle formulae for estimating onroad fuel economy was adjusted to 

reflect this 1.32 factor. The impact of A/C fuel use on onroad fuel economy including 

defrosting increased from 2.5% to 2.8%. Thus, instead of a range of 2.5-5.3% for the impact 
Draft Regulatory Impact Analysis 

2-28 

of A/C on onroad fuel consumption, the range is now 2.8-4.4%. The difference between the 

two estimates has been cut almost in half. 

There is one more adjustment that should be made to both estimates. Both EPA and 

NESCCAF assume that all A/C systems are in working condition. However, A/C systems do 

leak refrigerant, sometimes to the point where the system no longer works. Since the cost of 

repairing a leak can be significant, some vehicle owners do not always choose to repair the 

system. For its MOBILE6 emission model, EPA estimated the percentage of vehicles on the 

road with inoperative A/C systems as a function of vehicle age. Coupling these estimates 

with the amount of VMT typically driven by vehicles as a function of age, EPA estimates that 

8% of all the VMT in the U.S. is by vehicles with inoperative A/C systems. These systems do 

not impact fuel consumption. Thus, both the NESCCAF and EPA estimates should be 

multiplied by 0.92. Doing this, the impact of A/C on onroad fuel consumption is estimated to 

be 2.6-to-4.1%. 

2.3.2 Technologies That Improve Efficiency of Air Conditioning and Their 

Effectiveness 

EPA estimates that the CO2 emissions from A/C related load on the engine accounts 

for about 3.9% of total greenhouse gas emissions from passenger vehicles in the United 

States. This is equivalent to CO2 emissions of approximately 14 g/mi per vehicle. The A/C 

usage is inherently higher in hotter months and states; however, vehicle owners may use the 

A/C systems throughout the year in all parts of the nation. That is, people use A/C systems to 

cool and dry the cabin air for passenger comfort on hot humid days, as well as to de-humidify 

the air used for defogging/de-icing the front windshield to improve visibility. 

Most of the excess load on the engine comes from the compressor, which pumps the 

refrigerant around the system loop. Significant additional load on the engine may also come 

from electrical or hydraulic fan units used for heat exchange across the condenser and 

radiator. The controls that EPA believes manufacturers would use to earn credits for 

improved A/C efficiency would focus primarily, but not exclusively, on the compressor, 

electric motor controls, and system controls which reduce load on the A/C system (e.g. 

reduced ‘reheat’ of the cooled air and increased of use recirculated cabin air). EPA is 

proposing a program that would result in improved efficiency of the A/C system (without 

sacrificing passenger comfort) while improving the fuel efficiency of the vehicle, which has a 

direct impact on CO2 emissions. 

The cooperative IMAC program described above has demonstrated that average A/C 

efficiency can be improved by 36.4% (compared to a baseline A/C system), when utilizing 

“best-of-best” technologies. EPA considers a baseline A/C system contains the following 

components and technologies; internally-controlled fixed displacement compressor (in which 

the compressor clutch is controlled based on ‘internal’ system parameters, such as head 

pressure, suction pressure, and/or evaporator outlet temperature); blower and fan motor 

controls which create waste heat (energy) when running at lower speeds; thermostatic 

expansion valves; standard efficiency evaporators and condensers; and systems which 

circulate compressor oil throughout the A/C system. These baseline systems are also 

extraordinarily wasteful in their energy consumption because they add heat to the cooled air 
Air Conditioning 

2-29 

out of the evaporator in order to control the temperature inside the passenger compartment. 

Moreover, many systems default to a fresh air setting, which brings hot outside air into the 

cabin, rather than recirculating the already-cooled air within the cabin. 

The IMAC program indicates that improvements can be accomplished by a number of 

methods related only to the A/C system components and their controls including: improved 

component efficiency, improved refrigerant cycle controls, and reduced reheat of the cooled 

air. The program EPA is proposing would encourage the reduction of A/C CO2 emissions 

from cars and trucks by 40% from current baseline levels through a credit system. EPA 

believes that the component efficiency improvements demonstrated in the IMAC program, 

combined with improvements in the control of the supporting mechanical and electrical 

devices (i.e. engine speeds and electrical heat exchanger fans), can go beyond the IMAC 

levels and achieve a total efficiency improvement of 40%. The following sections describe 

the technologies EPA believes manufacturers can use to attain these efficiency improvements. 

2.3.2.1 Reduced Reheat Using a Externally-Controlled, Variable-Displacement 

Compressor 

The term ‘external control’ of a variable-displacement compressor is defined as a 

mechanism or control strategy where the displacement of the compressor adjusted 

electronically, based on the temperature setpoint and/or cooling demand of the A/C system 

control settings inside the passenger compartment. External controls differ from ‘internal 

controls’ that internal controls adjust the displacement of the compressor based on conditions 

within the A/C system, such has head pressure, suction pressure, or evaporator outlet 

temperature. By controlling the displacement of the compressor by external means, the 

compressor load can be matched to the cooling demand of the cabin. With internal controls, 

the amount of cooling delivered by the system may be greater than desired, at which point the 

cooled cabin air is then ‘reheated’ to achieve the desired cabin comfort. It is this reheating of 

the air which results reduces the efficiency of the A/C system – compressor power is 

consumed to cool air to a temperature less than what is desired. 

Reducing reheat through external control of the compressor is a very effective strategy 

for improving A/C system efficiency. The SAE IMAC team determined that an annual 

efficiency improvement of 24.1% was possible using this technology.29 EPA estimates that 

additional improvements with this technology, when fully developed, calibrated, and 

optimized to particular vehicle’s cooling needs - and combined with increased use of 

recirculated cabin air - can result in an efficiency improvement of 40%, compared to the 

baseline system. 

2.3.2.2 Reduced Reheat Using a Externally-Controlled, Fixed-Displacement or 

Pneumatic Variable-Displacement Compressor 

When using a fixed-displacement or pneumatic variable-displacement compressor 

(which controls the stroke, or displacement, of the compressor based on system suction 

pressure), reduced reheat can be realized by disengaging the compressor clutch momentarily 

to achieve the desired evaporator air temperature. This disengaging, or cycling, of the 

compressor clutch must be externally-controlled in a manner similar to that described in 
Draft Regulatory Impact Analysis 

2-30 

2.3.2.1. EPA believes that a reduced reheat strategy for fixed-displacement and pneumatic 

variable-displacement compressors can result in an efficiency improvement of 20%. This 

lower efficiency improvement estimate (compared to an externally-controlled variable 

displacement compressor) is due to the thermal and kinetic energy losses resulting from 

cycling a compressor clutch off-and-on repeatedly. 

2.3.2.3 Defaulting to Recirculated Cabin Air 

In ambient conditions where air temperature outside the vehicle is much higher that 

the air inside the passenger compartment, most A/C systems draw air from outside the vehicle 

and cool it to the desired comfort level inside the vehicle. This approach wastes energy 

because the system is continuously cooling the hotter outside air instead of having the A/C 

system draw it’s supply air from the cooler air inside the vehicle (also known as ‘recirc’). By 

only cooling this inside air (i.e. air that has been previously cooled by the A/C system), less 

energy is required, and A/C Idle Tests conducted by EPA indicate that an efficiency 

improvement 30% improvement is possible. A mechanically-controlled door on the A/C 

system’s air intake typically controls whether outside air, inside air, or a mixture of both, is 

drawn into the system. Since the typical ‘default’ position of this air intake door is outside air 

(except in cases where maximum cooling capacity is required, in which case, many systems 

automatically switch this door to the recirculated air position), EPA is proposing that, as cabin 

comfort and de-fogging conditions allow, an efficiency credit be granted if a manufacturer 

defaults to recirculated air whenever the outside ambient temperature is greater than 75°F. To 

maintain the desired quality inside the cabin (in terms of freshness and humidity), EPA 

believes some manufacturers will equip their A/C systems with humidity sensors, which will 

allow them to adjust the blend of fresh-to-recirculated air and optimize the controls for 

maximum efficiency. 

2.3.2.4 Improved Blower and Fan Motor Controls 

In controlling the speed of the direct current (DC) electric motors in an air 

conditioning system, manufacturers often utilize resistive elements to reduce the voltage 

supplied to the motor, which in turn reduces its speed. In reducing the voltage however, these 

resistive elements produce heat, which is typically dissipated into the air ducts of the A/C 

system. Not only does this waste heat consume electrical energy, it contributes to the heat 

load on the A/C system. One method for controlling DC voltage is to use a pulsewidth 

modulated (PWM) controllers for each motor. A PWM controller can reduce the amount of 

energy wasted, and based on Delphi estimates of power consumption for these devices, EPA 

believes that when more efficient speed controls are applied to both the blower and fan 

motors, an overall improvement in A/C system efficiency of 15% is possible.30 

2.3.2.5 Electronic Expansion Valve 

The expansion valve in an A/C system is used to “throttle” the flow high pressure 

liquid refrigerant upstream of the evaporator. By throttling the refrigerant flow, it is possible 

to control the amount of expansion (superheat) that the refrigerant will undergo, and by 

extension, the amount of heat removed from air passing through the evaporator. With a 

conventional, or thermostatic, expansion valve (TXV), the amount of expansion is controlled 
Air Conditioning 

2-31 

by an internal temperature reference to assure a constant temperature level for the expanded 

refrigerant gas, which is typically a few degrees Celsius above the freezing point of water 

(which may be too cool for the desired cabin comfort level). In the case where the air exiting 

the evaporator is too cool (or over-cooled), it will be necessary to reheat it by directing some 

of the airflow through the heater core. It is this reheating of the air which results in reduced 

system efficiency, as additional compressor energy is consumed in the process of overcooling the air. However, if the expansion of the refrigerant is controlled externally – such as 

by an electronic signal from the A/C control unit – it is possible to adjust the level of 

expansion, or superheat, to only to the level necessary to meet the current cooling needs of the 

passenger compartment. This electronic expansion valve (EXV) approach is similar to the 

reduced reheat strategy, except that instead of controlling the mass of refrigerant flowing 

through the system by controlling the compressor output, the mass flow is controlled by the 

EXV. By reducing the amount of refrigerant expanding, or controlling the level of superheat 

in the gas-phase refrigerant, the temperature of the evaporator can be increased and controlled 

to the point where reheating of the air is not necessary, the SAE IMAC team determined that 

an annual efficiency improvement of 16.5% is possible. EPA estimates the when fully 

developed, calibrated, and optimized to the requirements of particular system design, use of 

EXV technology can result in a 20% efficiency improvement over the baseline TXV system. 

2.3.2.6 Improved-Efficiency Evaporators and Condensers 

The evaporators and condensers in an A/C system are designed to transfer heat to and 

from the refrigerant – the evaporator absorbs heat from the cabin air and transfers it to the 

refrigerant, and the condenser transfer heat from the refrigerant to the outside ambient air. 

The efficiency, or effectiveness, of this heat transfer process directly effects the efficiency of 

the overall system, as more work, or energy, is required if the process is inefficient. A 

method for measuring the heat transfer effectiveness of these components is to determine the 

Coefficient of Performance (COP) for the system using the industry-consensus method 

described in the SAE surface vehicle standard J2765 – Procedure for Measuring System COP 

of a Mobile Air Conditioning System on a Test Bench.31 If these components can 

demonstrate a 10% improvement in COP versus the baseline components, EPA estimates that 

a 20% improvement in overall system efficiency is possible. 

2.3.2.7 Oil Separator 

The oil present in a typical A/C system circulates throughout the system for the 

purpose of lubricating the compressor. Because this oil is in contact with inner surfaces of 

evaporator and condenser, and a coating of oil reduces the heat transfer effectiveness of these 

devices, the overall system efficiency is reduced.32 It also adds inefficiency to the system to 

be “pushing around and cooling” an extraneous fluid that results in a dilution of the 

thermodynamic properties of the refrigerant. If the oil can be contained only to that part of 

the system where it is needed – the compressor – the heat transfer effectiveness of the 

evaporator and condenser will improve. The overall COP will also improve due to a 

reduction in the flow of diluent. The SAE IMAC team estimated that overall system COP 

could be improved by 8% if an oil separator was used.14 EPA believes that if oil is prevented 

from prevented from circulating throughout the A/C system, an overall system efficiency 

improvement of 10% can be realized. 
Draft Regulatory Impact Analysis 

2-32 

2.3.3 Technical Feasibility of Efficiency-Improving Technologies 

EPA believes that the efficiency-improving technologies discussed in the previous 

sections are available to manufacturers today, are relatively low in cost, and that their 

feasibility and effectiveness has been demonstrated by the SAE IMAC teams and various 

industry sources. EPA also believes that when these individual components and technologies 

are fully designed, developed, and integrated into A/C system designs, manufacturers will be 

able to achieve the estimated reductions in CO2 emissions and earn appropriate A/C 

Efficiency Credits, which are discussed in the following section. 

2.3.4 A/C Efficiency Credits 

In model years 2012 through and 2016, manufacturers would be required to 

demonstrate that vehicles receiving credit for A/C efficiency improvements are equipped with 

the type of components and/or controls needed to qualify for a certain level of CO2 credit. 

For model years 2014 and later, the design-based approach will be supplemented with a 

vehicle performance test, which has been modified slightly from that proposed in the GHG 

Mandatory Reporting Rule. In particular, EPA is proposing that the range of allowable 

ambient temperature for a valid A/C Idle Test be limited to 75 + 2 °F (as opposed to 68-to-86 

°F for a valid FTP test) and that the humidity in the test cell be limited to 50 + 5 grains of 

water per pound of dry air (where there are no such humidity constraints on an FTP test, only 

a humidity correction for NOx). This narrowing of the allowable range of ambient conditions 

was done to improve the accuracy and repeatability of the test results. Since the performance 

of an A/C system (and the amount of fuel consumed by the A/C system) are directly 

influenced by the heat energy, or enthalpy, of the air within the test cell – where criteria 

pollutants are not - it was necessary to control the enthalpy, and limit its effect on the test 

results. In addition, EPA is proposing a modification to the interior fan settings for vehicles 

with manual A/C controls. In the proposed reporting rule, vehicle with manual A/C controls 

were to be run on the ‘high’ fan setting for the duration of the A/C on portion of the test. 

However, EPA believes that this fan speed setting would unduly penalize vehicles with 

manual controls when compared to those with automatic control - as automatic controls adjust 

the fan speed to lower setting as the target interior temperature is reached (which is similar to 

what a driver does on a vehicle with manual controls). In recognition of this disparity in the 

proposed test procedure, EPA is revising the test to allow vehicles with manual A/C controls 

to average the result obtained on the high fan speed setting with the result obtained on the low 

fan speed setting. The additional 10-minute idle sequence on the low fan speed setting is to 

be run immediately following the high fan sequence (no additional prep cycle is required). 

This revised performance test will assure that the A/C components and/or system control 

strategies a manufacturer chooses to implement are indeed delivering the efficiency gains 

projected for each. The performance test discussed in section II of the preamble is the A/C 

Idle Test, but in that section, EPA also discusses how a modified SC03 test could also be used 

to measure the efficiency of A/C systems. 

To establish an average A/C CO2 rate for the A/C systems in todays vehicles, the EPA 

conducted laboratory tests to measure the amount of additional CO2 a vehicle generated due 

to A/C use on the proposed Idle Test. 33 The results of this test program are summarized in 

Table 2-11, and represent a wide cross-section of vehicle types in the U.S. market. The 
Air Conditioning 

2-33 

average A/C CO2 result from this group of vehicles is the value against which results from 

vehicle testing (beginning in 2014) will be compared. The EPA conducted laboratory tests to 

tested over 60 vehicles representing a wide range of vehicle types (e.g. compact cars, midsize 

cars, large cars, sport utility vehicles, small station wagons, and standard pickup trucks). 

Table 2-11 Summary of A/C Idle Test Study Conducted by EPA at the National Vehicle Fuel and 

Emissions Laboratory 

Vehicle Makes Tested 19 

Vehicle Models Tested 29 

Model Years Represented (number of vehicles in each model 

year) 

1999 (2), 2006 (21), 2007 (39) 

EPA Size Classes Represented Minicompact, Compact, Midsize, and 

Large Cars 

Sport Utility Vehicles 

Small Station Wagons 

Standard Pickup Trucks 

Total Number of A/C Idle Tests 62 

Average A/C CO2 (g/min) 21.3 

Standard Deviation of Test Results (+ g/min) 5.8 
Draft Regulatory Impact Analysis 

2-34 

The majority of vehicles tested were from the 2006 and 2007 model years and their 

A/C systems are representative of the ‘baseline’ technologies, in terms of efficiency (i.e. to 

EPA’s knowledge, these vehicles do not utilize any of the efficiency-improving technologies 

described in Table 2-12). The individual test results from this testing are shown in Figure 2-4. 

EPA attempted to find a correlation between the A/C CO2 results and a vehicle’s interior 

volume, footprint, and engine displacement, but was unable to do so, as there is significant 

“scatter” in the test results. This scatter is generally not test-to-test variation, but scatter 

amongst the various vehicle models and types – there is no clear correlation between which 

vehicles perform well on this test, and those which do not. EPA did attempt to find a 

correlation between the idle test results and a vehicle’s interior volume, footprint, or engine 

displacement, but no clear correlation could be found. What is clear, however, is that load 

placed on the engine by the A/C system is not consistent, and in certain cases, larger vehicles 

perform better than smaller ones, in terms of their A/C CO2 result. 

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0 10 20 30 40 50 60 70

Test Number

A/C CO2 (g/min)

Average A/C CO2 rate = 21.3 g/min

Figure 2-4 EPA A/C Idle Test Results from Various Vehicle Model Types 

Part of this variation in the proposed A/C Idle Test results may be due to the 

components a manufacture chooses to use in a particular vehicle. Where components such as 

compressors are shared across vehicle model types (e.g. a compressor may be ‘over-sized’ for 

one application, but the use of a common part amongst multiple model types results in a cost 

savings to the manufacturer). Some of the variation may also be due to the amount of cooling 

capacity a vehicle has at idle. One manufacturer indicated that one of their vehicles which 

produced a below-average A/C CO2 result, is also known for having A/C performance at idle 

which does not meet customer expectations, but off-idle, performs very well. Therefore, it 
Air Conditioning 

2-35 

will be necessary for manufacturers to balance the cooling capacity of the A/C system under 

idle conditions against the overall A/C system efficiency. 

Some of this variation between various models may also be due to the efficiency of the 

fan(s) which draw air across the condenser – since an external fan is not placed in front of the 

vehicle during the A/C Idle Test, it is the vehicle’s fan which is responsible for rejecting heat 

from the condenser (and some models may do this more efficiently than others). In this case, 

EPA believes that an SC03-type test – run in a full environmental chamber with a “roadspeed” fan on the front of the vehicle – would be a better measure of how a vehicle’s A/C 

system performs under transient conditions, and any limitations the system may have at idle 

could be counter-balanced by improved performance and efficiency elsewhere in the drive 

cycle. However, since idle is significant part of real-world and FTP drive cycles (idle 

represents 18% of the FTP), EPA believes that the focus in this rulemaking on A/C system 

efficiency under idle conditions is justified. 

 The average A/C CO2 result for the vehicles tested was 21.3 g/min. Starting in the 

year 2014, in order to qualify for A/C Efficiency Credits, it will be necessary for 

manufacturers to demonstrate the efficiency of their systems by running an A/C Idle Test on 

each vehicle model for which they are seeking credit. To qualify for credit, it will be 

necessary for each model to achieve an A/C CO2 result less than or equal to 14.9 g/min 

(which is 30% less than the average value observed in the EPA testing). EPA chose the 30% 

improvement over the “average” value to drive the fleet of vehicles toward A/C systems 

which approach or exceed the efficiency of current best-in-class vehicles. EPA believes this 

approach will cause manufacturers to tailor the size A/C components and systems to the 

cooling needs of a particular vehicle model and focus on the overall efficiency of their A/C 

systems. EPA believes this approach strikes a reasonable balance between avoiding granting 

credits for improvements which would occur in any case, and encouraging A/C efficiency 

improvements which would not otherwise occur. Once manufacturers begin using the 

technologies described in Table 2-12 – and develop these technologies for the requirements of 

each vehicle, with a focus on achieving optimum efficiency – EPA believes it will be possible 

to demonstrate that a vehicle is indeed achieving the reductions in A/C CO2 emissions that are 

estimated for this rulemaking. 

We believe that it is possible to identify the A/C efficiency-improving components 

and control strategies most-likely to be utilized by manufacturers and are assigning a CO2

‘credit’ to each. In addition, EPA recognizes that to achieve the maximum efficiency benefit, 

some components can be used in conjunction with other components or control strategies. 

Therefore, the system efficiency synergies resulting from the grouping of three or more 

individual components are additive, and will qualify for a credit commensurate with their 

overall effect on A/C efficiency. A list of these technologies – and the credit associated with 

each – is shown in Table 2-12. If the more than one technology is utilized by a manufacturer 

for a given vehicle model, the A/C credits can be added, but the maximum credit possible is 

limited to 5.7 g/mi. This maximum credit represents a 40% improvement over a 14.3 g/mi 

per vehicle CO2-equivalent impact due to A/C use. This 14.3 g/mi impact is derived from the 

EPA’s 2006 estimate of fuel consumption due to A/C use of 12.11 g/mi. However, the 2006 

estimate needed to be adjusted upward to reflect the increased prevalence of “automatic” A/C 

controls in modern vehicles (the Phoenix study used in the EPA’s 2006 estimate was from 
Draft Regulatory Impact Analysis 

2-36 

1990s-vintage vehicles, which do not include a significant number of vehicles with automatic 

climate control systems). To derive the newer estimate, a scenario was first modeled in which 

100% of vehicles used in the Phoenix study were equipped with automatic A/C systems 

(which increases the amount of time the compressor is engaged in moderate ambient 

conditions), which resulted in the 12.11 g/mi estimate increasing to 17.85 g/mi. Industry and 

supplier estimates were then used for the number of vehicles equipped with automatic A/C 

systems - as well as vehicle sales data from the 2009 Ward’s Automotive Yearbook – and 

projected that 38% of new vehicles are equipped with automatic A/C systems.34 Finally, the 

percentages of vehicles with and without automatic A/C systems were multiplied by their 

respective impact on fuel consumption (0.62 x 12.11 + 0.38 x 17.85) to produce our estimate 

of 14.3 g/mi. This credit is the same for cars and trucks because the A/C components, cooling 

requirements, and system functions are similar for both vehicle classes. Therefore, EPA 

believes the level of efficiency improvement and the maximum credit possible should be 

similar for cars and trucks as well. 

Table 2-12: Efficiency-Improving A/C Technologies and Credits 

Technology Description Estimated Reduction 

in A/C CO2 Emissions 

A/C Credit (g/mi 

CO2) 

Reduced reheat, with externally-controlled, 

variable-displacement compressor 

30% 1.7 

Reduced reheat, with externally-controlled, 

fixed-displacement or pneumatic variable 

displacement compressor 

20% 1.1 

Default to recirculated air whenever ambient 

temperature is greater than 75 °F 

30% 1.7 

Blower motor and cooling fan controls which 

limit waste energy (e.g. pulsewidth modulated 

power controller) 

15% 0.9 

Electronic expansion valve 20% 1.1 

Improved evaporators and condensers (with 

system analysis on each component indicating 

a COP improvement greater than 10%, when 

compared to previous design) 

20% 1.1 

Oil Separator 10% 0.6 

The estimates for the percent reduction in A/C CO2 for each technology is based in 

part on the results of SAE IMAC Team 2 (Improved Efficiency) final report, which both 

provides a baseline for calculating creditable improvements, and also provides a level of 

improvement for each technology. The estimated percent reduction in A/C CO2 emissions for 
Air Conditioning 

2-37 

each was adjusted upward to reflect continuous improvement in the design, calibration, and 

implementation of these technologies. These technologies, which, when combined, can allow 

manufacturers to achieve the 40% reduction in CO2 emissions. 

2.4 Costs of A/C reducing technologies 

This section describes the cost estimates for reductions in air conditioner related GHG 

emissions as well as the cost savings that result from improved technologies. These estimates 

are largely determined from literature reviews of publications and public presentations made 

by parties involved in the development and manufacture of A/C systems as well as from EPA 

analyses. The cost savings are estimated from the literature as well as the supplemental 

deterioration models based analysis described above. 

For leakage, or direct, emissions, EPA assumes that reductions can be achieved 

without a change in refrigerant, though it is possible that by 2020 a new technology and 

refrigerant will be a much more viable option than it is today. For example, an alternative 

refrigerant with a GWP less than 150 and can be used directly in current A/C systems will be 

able to meet the leakage credit requirements without significant engineering changes or cost 

increases. However, in order to reduce the leakage in conventional R134a systems by 50%, it 

has been estimated that the manufacturer cost would increase by $15 per vehicle in 2002 

dollars, employing existing off-the-shelf technologies such as the ones included in the J2727 

leakage charts.I

 Converting this to 2007 dollars using the GDP price deflator (see Appendix 

3.A of the Draft Joint TSD) results in a cost of $17. With the indirect cost markup factor of 

1.11 for a low complexity technology the compliance cost becomes $19. Using this as the 

2012MY cost and applying time based learning results in a 2016MY cost of $17 for leakage 

reduction technology. Table 2-13 shows how these costs may be distributed on a year by year 

basis as the proposed program phases in over 5 years. 

We expect that a reduction in leakage will lead to fewer servicing events for 

refrigerant recharge. In 2006, the EPA estimated the average cost to the vehicle owner for a 

recharge maintenance visit was $100. However, recent information indicates that the industry 

average cost of recharging an automotive air conditioner is $147.35 With the new AC 

systems, such $100 or $147 maintenance charges could be moved delayed until later in the 

vehicle life and, possibly, one of more events could be eliminated completely. This provides 

potential savings to consumers as a result of the new technology. Note that these potential 

maintenance savings are not included in the cost and benefit analysis presented in Chapters 6 

and 8 of this DRIA. However, EPA intends to include an estimate of maintenance savings in 

the final rule analysis and believe that this higher estimate for the cost of recharging an A/C 

system would serve as the basis for those maintenance savings in the cost analysis of the final 

rule. 

 I

 Author unknown, Alternative Refrigerant Assessment Workshop, SAE Automotive Alternative Refrigerant 

Symposium, Arizona, 2003. 
Draft Regulatory Impact Analysis 

2-38 

For indirect CO2 emissions due to A/C, it has been estimated that a 25-30% reduction 

can be achieved at a manufacturer cost of 44€, or $51 in 2005 dollars.J

 The IMAC Efficiency 

Improvement team of the Society of Automotive Engineers realized an efficiency 

improvement of 36.4% based on existing technologies and processes.29 For the idle test, EPA 

estimates that further reductions with software controls can achieve a total reduction of 40%. 

Converting the $51 value to 2007 dollars results in $54 (using the GDP price deflator as 

explained in Appendix 3.A of the Draft Joint TSD) and applying a 1.11 indirect cost 

multiplier for a low complexity technology (as described in Chapter 3 of the Draft Joint TSD) 

gives a total compliance cost of $60. Using this as the 2012MY cost and applying time based 

learning (as described in Chapter 3 of the Draft Joint TSD) results in a 2016MY cost of $53. 

In the 2008 Advance Notice of Proposed Rule, EPA presented a quick analysis of the 

potential fuel savings associated with the control of indirect emissions via new AC 

technology. There EPA assumes a reference 2010 fuel economy of 30 mpg for cars and 24 

for trucks. With a 20% real-world shortfall, this becomes 24 and 19 mpg respectively. As 

described in appendix A of the GHG advanced notice (and above), A/C impacts overall fuel 

consumption by 2.6-to-4.1%, and that an ultimate efficiency improvement of 40% is 

achievable. EPA used the AEO 2008 fuel price, discount values, vehicle scrappage and VMT 

figures employed elsewhere in the advanced proposal to calculate a $96 cost savings for cars 

and $130 for trucks for the life of the vehicle. Assuming the same 0.23 factor to account for 

rebound and emissions, these savings increase to $118 for cars and $159 for trucks. This was 

noted in the GHG advance notice as being a potentially significant cost savings for the vehicle 

owner compared to the cost of the efficiency improvements. EPA has not updated this 

analysis for this rule. For the analysis in support of this rule, as presented in Chapter 6 of this 

DRIA, the indirect AC fuel savings has been included in the total fuel savings resulting from 

the proposal. 

Table 2-13 presents the compliance costs associated with new AC technology with 

estimates for how those costs might change as vehicles with the technology are introduced 

into the fleet. Costs shown are averages per vehicle since not all vehicles would include the 

new technology but would, instead, include the technology according to the penetration 

estimates shown in the table. 

Table 2-13: Estimated Costs in each Model Year for New AC Technology, 2007 dollars 

 2012 2013 2014 2015 2016 

Penetration 25% 40% 55% 75% 85% 

AC Leakage (Direct) $4 $7 $9 $13 $14 

AC Indirect $13 $21 $29 $40 $45 

Total $18 $28 $39 $53 $60 

 

 J

 The 0.87 Euro-US dollar conversion is dated today but was valid in 2005. 2005 Euros are converted to 2005 

US dollars then 2005 US dollars are converted to 2007 US dollars. 
Air Conditioning 

2-39 

2.5 Air Conditioning Credit Summary 

A summary table is shown with the estimated usage of the A/C credits. EPA projected 

the penetration rates as a reasonable ramp to the 85% penetration cap in 2016. The 85% 

penetration cap was set to maintain consistency with the technology penetration caps used in 

OMEGA. The car and truck sales fractions were drawn from an adjusted version of AEO 

2009, as documented in DRIA Chapter 5. As documented above, no use of alternative 

refrigerant is projected in this in this analysis, although this assumption may be revisited in 

the final rule (Table 2-14). 

 Table 2-14 : Credit Summary with Estimated Penetration Rates

Model Year 

2012 2013 2014 2015 2016 

Estimated Penetration 25% 40% 60% 80% 85% 

Car Sales Fraction 63% 64% 64% 66% 66% 

Truck Sales Fraction 37% 36% 36% 34% 34% 

 

Car Direct Credit 2.0 3.1 4.7 6.2 6.6 

Car Indirect Credit 1.4 2.3 3.4 4.6 4.8 

Total Car Credit 3.0 4.8 7.2 9.6 10.2 

 

Truck Direct Credit 1.6 2.5 3.8 5.0 5.4 

Truck Indirect Credit 1.4 2.3 3.4 4.6 4.8 

Total Truck credit 3.4 5.4 8.1 10.8 11.5 

 

Fleet average credits 3.1 5.0 7.5 10.0 10.6 
Draft Regulatory Impact Analysis 

2-40 

References 

All references can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472.

 1

 IPCC. Chapter 2. Changes in Atmospheric Constituents and in Radiative Forcing. September 2007. 

2

 Schwarz, W., Harnisch, J. 2003. “Establishing Leakage Rates of Mobile Air Conditioners.” Prepared for the 

European Commission (DG Environment), Doc B4-3040/2002/337136/MAR/C1. 

3

 Vincent, R., Cleary, K., Ayala, A., Corey, R. 2004. “Emissions of HFC-134a from Light-Duty Vehicles in 

California.” SAE 2004-01-2256. 

4

 EPA, 2009, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007. 

http://www.epa.gov/climatechange/emissions/usinventoryreport.html 

5

 State of California, Manufacturers Advisory Correspondence MAC #2009-01, “Implementation of the New 

Environmental Performance Label,” http://www.arb.ca.gov/msprog/macs/mac0901/mac0901.pdf. 

6

 State of Minnesota, “Reporting Leakage Rates of HFC-134a from Mobile Air Conditioners,” 

http://www.pca.state.mn.us/climatechange/mac-letter-082908.pdf. 

7

 Society of Automotive Engineers, “IMAC Team 4 – Reducing Refrigerant Emissions at Service and Vehicle 

End of Life,” June, 2007. 

8

 Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy. Transportation Energy Data 

Book: Edition 27. 2008. 

9

 Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2005. 

http://epa.gov/climatechange/emissions/downloads06/07CR.pdf 

10 EPA, “Fuel Economy Labeling of Motor Vehicle Revisions to Improve Calculation of Fuel Economy 

Estimates Final Technical Support Document (179 pp, 2.1MB, EPA420-R-06-017, December 2006 

11 Ikegama, T., Kikuchi, K.. 2006. “Field Test Results and Correlation with SAEJ2727.” Proceedings of the SAE 

7th Alternative Refrigerant Systems Symposium. 

12 Atkinson, W., Baker, J., Ikegami, T., Nickels, P. 2006. “Revised SAEJ2727: SAE Interior Climate Control 

Standards Committee Presentation to the European Commission.” 

13 EPA. 2009 U.S. Greenhouse Gas Inventory Report. INVENTORY OF U.S. GREENHOUSE GAS 

EMISSIONS AND SINKS: 1990-2007 (April 2009) 

14 Society of Automotive Engineers, “IMAC Team 1 – Refrigerant Leakage Reduction, Final Report to 

Sponsors,” 2006. 

15 Society of Automotive Engineers Surface Vehicle Standard J2727, issued August 2008, http://www.sae.org 

16 Minnesota Pollution Control Agency, “Model Year 2009 Leakage Rate List,” 

http://www.pca.state.mn.us/climatechange/mobileair.html. 
Air Conditioning 

2-41 

 17 Schwarz, W., “Emission of Refrigerant R-134a from Mobile Air-Conditioning Systems,” Study conducted for 

the German Federal Environmental Office, September, 2001. 

18 “A/C Triage – Ensuring Replacement Compressor Survival, “ AC Delco Tech Connect, Volume 12, Number 

5, January/February 2005, 

http://www.airsept.com/Articles/CompressorGuard/ACDelcoTechConnectJanFeb05.pdf. 

19 Johnson, Valerie H., “Fuel Used for Vehicle Air Conditioning: A State-by-State Thermal Comfort-Based 

Approach,” SAE 2002-01-1957, 2002. 

20 Rugh, John P, Valerie Hovland, and Stephen O. Andersen, “Significant Fuel Savings and Emission Reductions 

by Improving Vehicle Air Conditioning,” Mobile Air Conditioning Summit, Washington DC., April 14-15, 

2004. 

21 California Environmental Protection Agency Air Resources Board, “STAFF REPORT: Initial statement of 

reasons for proposed rulemaking, public hearing to consider adoption of regulations to control greenhouse gas 

emissions from motor vehicles,” 2004. 

22 “Reducing Greenhouse Gas Emissions from Light-Duty Motor Vehicles,” Northeast States Center for a Clean 

Air Future, September 2004. 

23 Fuel Economy Labeling of Motor Vehicles: Revision to Improve Calculation of Fuel Economy Estimates; 

Final Rule, 71 FR 77872, December 27, 2006. 

24 Koupal, J., “Air Conditioning Activity Effects in MOBILE6” EPA Report Number M6.ACE.001, 1998. 

25 EPA Technical Support Document for Fuel Economy Label Regulations, November, 2006. 

26 Nam, E.K., “Understanding and Modeling NOx Emissions from Automobiles During Hot Operation,” PhD 

Thesis, University of Michigan, 1999. 

27 Nam, E. K., “Understanding and Modeling NOx Emissions from Air Conditioned Automobiles,” SAE 

Technical Paper Series 2000-01-0858, 2000. 

28 “Reducing Greenhouse Gas Emissions from Light-Duty Motor Vehicles,” Northeast States Center for a Clean 

Air Future, September 2004. 

29 Society of Automotive Engineers, “IMAC Team 2 – Improved Efficiency, Final Report,” April 2006. 

30 Memo to docket, “Meeting with Delphi and Presentation to EPA,” March 2009. 

31 Society of Automotive Engineers Surface Vehicle Standard J2765, issued October 2008, http://www.sae.org. 

32 Barbat, Tiberiu, et al, “CFD Study of Phase Separators in A/C Automotive Systems,” SAE 2003-01-0736, 

2003. 

33 EPA, “AC Idle Test Results_Summary for docket,” August 2009. 

34 “2009 Ward’s Automotive Yearbook,” Ward’s Automotive Group, 2009. ISBN Number 978-0-9105-89-26-0. 

35 California Air Resources Board, “Staff Analysis of Proposed Early Action for Climate Change Mitigation in 

California,” 2007, http://www.arb.ca.gov/cc/hfc-mac/documents/hfcdiy.pdf. 

Technical Basis of the Standards 

3-1 

CHAPTER 3: Technical Basis of the Standards 

3.1 Technical Basis of the Standards 

3.1.1 Summary 

As explained in section III.D of the preamble to the proposed rule, in developing the 

proposed standard, EPA built on the technical work performed by the State of California 

during its development of its statewide GHG program. This led EPA to evaluate a Clean Air 

Act national standard which would require the same degree of technology penetration that 

would be required for California vehicles under the California program. In essence, EPA 

evaluated the stringency of the California Pavley 1 program but for a national standard. 

However, as further explained in the preamble, before being able to do so, technical analysis 

was necessary in order to be able to assess what would be an equivalent national new vehicle 

fleet-wide CO2 performance standards for model year 2016 which would result in the new 

vehicle fleet in the State of California having CO2 performance equal to the performance from 

the California Pavley 1 standards. This technical analysis is documented in this sub-chapter 

of the DRIA. 

Table 3-1 presents the calculated emission levels at which the national GHG standard 

would ensure that vehicle sales in California of federally compliant vehicles would have fleet 

average GHG emissions that are equal to the fleet average that would be achieved under the 

California program described in Sections 1900, 1960 and 1961.1 of Title 13, California Code 

of Regulations (“Pavley I”) by model year 2016: 

Table 3-1: Fleet Average National CO2Emission Levels for Model Years 2012-2016 

MODEL YEAR 

2012 2013 2014 2015 2016 

Fleet Average Tailpipe Emission Level 

(CO2 gram / mile) 288 281 275 263 250 

Manufacturer’s use of credits and other program flexibilities may alter the program 

stringency beyond that which is shown here. 
Draft Regulatory Impact Analysis 

3-2 

3.1.2 Overview of Equivalency Calculation. 

The calculation of the fleet-wide national MY 2015 and MY 2016 CO2 emission levels 

which would be equivalent to California’s Pavley I program is briefly outlined here. 

1. Based on the California new vehicle fleet mix (predicted sales) and the CA program 

provisions, EPA calculated the fleetwide average CO2 emissions achieved in CA from 

the 2015 and 2016 model year fleets. 

2. The estimate of fleetwide average CO2 emissions was disaggregated into achieved car 

and truck CO2 emission levels at the national level using the new car and truck 

definitions proposed for this rule. 

3. Based on the anticipated national fleet mix, the achieved car and truck levels were 

weighted together to determine the national targets which would achieve reductions 

equivalent to Pavley I in California. 

This calculation accounts for the compositional difference between the CA vehicle fleet 

and the National fleet (i.e., CA has a higher proportion of cars than the average state), and for 

various parameters in the CA program. 

3.1.2.1 Calculating CO2 Equivalent Emissions under the California Program 

To calculate the CO2 equivalent emissions in California under Pavley I, the California 

Passenger Car and Light Truck standards were combined with the California fleet mix in 

order to calculate the anticipated emissions under the California standards from the California 

fleet. 

The Passenger Car and Light Truck Standards were drawn from Sections 1900, 1960 

and 1961.1 of Title 13, California Code of Regulations. Intermediate and small volume 

manufacturer standards were calculated based on guidance within the regulation, as well as 

EPA analysis of current manufacturer product mix. These standards, less 2 grams per mile of 

CO2 equivalent emissions due to methane (CH4) and nitrous oxide (N2O), are shown in Table 

3-2. CH4 and N2O were excluded because the proposed EPA program separately addresses 

these emissions (Preamble section III). 
Technical Basis of the Standards 

3-3 

Table 3-2: California Regulatory Standards excluding CH4 and N2O (grams CO2 equivalent per mile) 

MY 2015 

Standard 

MY 2016 

Standard 

California Car (PC/LDT1) Standard 211 203 

Intermediate/Small Volume 

Manufacturer California Car Standard 314 229 

CA LDT2/MDPV Standard 339 330 

Intermediate/Small Volume 

Manufacturer LDT2/MDPV Standard 360 357 

The projected fleet mix, as defined under Pavley I, was then determined in California. 

Significantly, the California program deviates from historic definitions of “classic” cars and 

trucks. In brief, Pavley I defines “PC/LDT1” as passenger cars and light duty trucks below 

3,750 pounds, while “LDT2” include all trucks intended to convey passengers that weigh less 

than 10,000 pounds. The details of this classification scheme are found in the California 

regulations. 

In order to estimate the emission contribution of PC/LDT1 and LDT2 in California, 

EPA estimated the respective fleet fractions. EPA estimated the national sales mix in 2015 

and 2016 at 60% passenger cars and 40% light duty trucks. This estimate is supported by the 

Energy Information Administrations’ Annual Energy Outlook 2009, which estimated 

passenger cars at 59.4% of 2016 new vehicle sales in its published reference case.1

 Due to the 

American Recovery and Reinvestment Act of 2009, the Annual Energy Outlook reference 

case has since been updated to project 2016 sales at 57.1% passenger cars. 

The projected 60% passenger cars, 40% light duty trucks sales fraction was then 

applied to the California vehicle fleet mix. In such a scenario, the California Air Resource 

Board (ARB) estimated that PC/LDT1s comprise approximately 66% of the new light duty 

vehicle fleet in California and that LDT2s comprise the remainder (34%). 

Once the PC/LDT1 and LDT2 fractions of California new vehicle sales were 

determined, EPA estimated the fraction of vehicle sales in the intermediate and small volume 

manufacturer categories. These manufacturers, which sell less than 60,000 vehicles per year 

in California, are subject to less stringent emission standards under Pavley I. While estimates 

of future sales by manufacturer fluctuate, manufacturers such as Subaru, Porsche, Hyundai 

and Volkswagen were considered beneath this threshold for the purpose of this analysis. 

Based on EPA market analysis, small/intermediate volume manufacturers were estimated at 

9% of total California PC/LDT1 sales and 5% of total California LDT2 Sales. The final 

product mix assumed in California in 2015 and 2016 under a 60/40 national sales scenario is 

shown in Table 3-3. 
Draft Regulatory Impact Analysis 

3-4 

Table 3-3: California Sales Mix under a 60% Classic Car 40% Classic Truck National Sales Scenario 

Sales % 

PC/LDT1 Sales 60% 

Intermediate Volume PC/LDT1 

sales 

6% 

California LDT2 Sales 32% 

Intermediate Volume LT2 sales 2% 

 

The product mix was multiplied by the relevant standard and summed in order to 

calculate the achieved average CO2 emissions for the new California fleet. As an example in 

2016: 

Achieved Fleetwide CO2 Equivalent Emissions = 

(PC/LDT1 standard x PC/LDT1 Percentage) + (LT2 standard x LT2 Percentage) + (Intermediate Volume 

PC/LDT1 standard x Intermediate Volume PC/LDT1 Percentage) + Intermediate Volume LT2 standard x 

Intermediate Volume LT2 Percentage) 

= 

(0.6 x 203) + (0.06 x 229) + (0.32 x 330) + (0.02 x 357) = 248 grams. 

(eq.1)

Based on the projected 60% passenger car, 40% light duty truck national sales mix (Table 

3-3), the achieved fleetwide CO2 equivalent tailpipe emission level expected in California in 

2016 is 248 grams / mile. 

This analysis was repeated for model year 2015. In order to achieve equivalency, the 

national program must produce a fleetwide average emission level in California that is no 

higher than 261 grams CO2 / mile in 2015 and 248 grams CO2 / mile in 2016. 

3.1.2.2 Translating the CA fleetwide average emissions into Cars (Passenger 

Automobiles) and Trucks (Non-Passenger Automobiles) 

In order to describe the national fleet, the California fleet-wide average CO2 emission 

level was translated into car and truck achieved emissions levels. However, the regulatory 

definitions in EPA’s Title II programs differ. Passenger Automobiles (PA) are defined as 

two wheel drive SUVs below 6,000 lbs. gross vehicle weight as well as classic cars. The 

remaining light duty fleet is defined as Non-Passenger Automobiles (NPA) (Table 3-4). 
Technical Basis of the Standards 

3-5 

Table 3-4: Summary of Fleet Description Methods 

REGULATOR CAR DEFINITION TRUCK DEFINITION 

National Highway Transit 

Safety Association (CAFE 

Through MY 2010) 

Car – Passenger Car Truck – LDT1-4 and MDPV 

California ARB Car – PC + LDT1 Light Truck – LDT2-4 and MDPV 

EPA Passenger Automobile – PC 

+ 2 wheel drive SUVs below 

6,000 GVW 

Non-Passenger Automobile – Remaining 

light duty fleet 

To disaggregate the combined California fleet emission level into PA and NPA 

vehicles, the 2015 and 2016 California achieved levels were multiplied by ratios derived from 

National Highway Transit Association (NHTSA) analysis of the emissions from PA and NPA 

vehicles.2

 Based on the NHTSA analysis, EPA estimates that PAs have an emission 

contribution equivalent to 91% of the California MY 2016 fleet average, while NPA have an 

emission contribution equivalent to 119% of the California achieved CO2 fleet average 

emissions. These ratios, and the PA/NPA achieved emission levels, are shown in Table 3-5. 

Table 3-5: PA and NPA Emission Levels under Pavley I 

Regulatory Class Ratio MY 2015 

Achieved 

Emission 

Level 

MY 2016 

Achieved 

Emission 

Level 

PA 0.91 238 227 

NPA 1.19 312 297 

3.1.2.3 Calculating the 2015 and 2016 Fleetwide CO2 emission Targets under the EPA 

Proposal 

To determine the MY 2015 and MY 2016 fleetwide targets under the EPA proposal, 

the achieved emission levels from PA and NPA (Table 3-5) were reweighted into a national 

fleet-wide average based upon the anticipated national fleet of 60% passenger car, 40% light 

duty truck. Based on NHTSA analysis presented in the MY 2011 CAFE final rule, this fleet 

is expected to be comprised of approximately 66.4% PA and 33.6% NPA.3

 The PA and NPA 

achieved emission levels were weighted into a national fleetwide average based upon these 

percentages. The resulting 2015 fleetwide target is 263 grams CO2 / mile, while the 2016 

target is 250 grams CO2 /mile. 
Draft Regulatory Impact Analysis 

3-6 

. 

3.1.2.4 Calculation of 2012-2014 “California Equivalent” Targets 

The methodology used to calculate the 2015 and 2016 California Equivalent levels 

was repeated for the 2012-2014 model years. The most significant departure from the 

previously described methodology is that sales projections differ in MY 2012-2014 as 

compared to MY 2015-2016. 

EPA assessment of projected vehicle sales during MY 2012-2014 supported a lower 

proportion of car sales than the 60% fraction projected during MY 2015-2016. March 2009 

AEO vehicle sales estimates were therefore substituted in these earlier years. Using the 

methodology described in section Error! Reference source not found., the AEO estimates 

were used to project PC/LDT1 fractions in CA, and PA and NPA sales fractions nationally 

(Table 3-6). 

Table 3-6: National PA and NPA Sales Fractions estimated in March 2009 AEO Projections 

Regulatory Class MY 2012 MY 2013 MY 2014 

AEO Car fraction 55.0% 56.1% 57.4% 

AEO Truck fraction 45.0% 43.9% 42.6% 

PC/LDT1 in CA 61.0% 62.1% 63.4% 

LT2 in CA 39.0% 37.9% 36.6% 

PA fraction Nationally 62.1% 63.0% 64.1% 

NPA fraction Nationally 37.9% 37.0% 35.9% 

Per the previously described methodology, the calculated CA sales fractions were then 

multiplied by the Pavley I standards for MY 2012 – MY 2014 (Table 3-7). Consistent with 

the 2015/16 analysis, small manufacturers were assumed to remain a constant 9% of 

California PC/LDT1 sales and 5% of California LDT2 Sales. 

Table 3-7: 2012-2014 California Regulatory Standards 

excluding CH4 and N2O (grams CO2 equivalent per mile) 

MY 2012 MY 2013 MY 2014 

California Car (PC/LDT1) Standard 231 225 220 

Intermediate/Small Volume 

Manufacturer California Car Standard 314 314 314 

CA LDT2/MDPV Standard 359 353 348 

Intermediate/Small Volume 

Manufacturer LDT2/MDPV Standard 360 360 360 

Comment [TSh1]: Where is this 

meant to point? 
Technical Basis of the Standards 

3-7 

The resulting achieved emission levels in California are 286 grams CO2 / mile in MY 

2012, 279 grams CO2 / mile in MY 2013 and 273 grams CO2 / mile in MY 2014. In order to 

derive PA and NPA achieved emission levels, these achieved emission levels were multiplied 

by MY-specific ratios derived from National Highway Transit Association (NHTSA) 

analysis. 4

The projected PA and NPA emission levels were then recombined into a national fleet 

achieved emission level based on the national PA and NPA sales fractions shown in Table 3-6 

(Table 3-8). 

Table 3-8: PA and NPA Emission Levels under Pavley I 

Regulatory Class MY 2012 

Achieved 

Emission 

Level 

MY 2013 

Achieved 

Emission 

Level 

MY 2014 

Achieved 

Emission 

Level 

PA 260 253 248 

NPA 334 328 323 

Fleet Average 288 281 275 

3.2 Analysis of Footprint Approach for Establishing Individual Company Standards 

One of the fundamental issues associated with the vehicle fleet average CO2emission 

standard is the structure of the standard; i.e., the basis for the determination of the standard for 

each vehicle manufacturer. 

Vehicle CO2 emissions are closely related to fuel economy. Over 99 percent of the 

carbon atoms in motor fuel are typically converted to tailpipe CO2, and therefore, for any 

given fuel with a fixed hydrogen-to-carbon ratio, the amount of CO2 emitted (grams) is 

directly correlated to the volume of fuel that is consumed (gallons), and therefore CO2 g/mile 

is essentially inversely proportional to vehicle fuel economy, expressed as miles per gallon. 

As part of the CAFE program, EPA measures vehicle CO2 emissions and converts them to 

mpg and generates and maintains the federal fuel economy database. Additionally, EPA 

calculates the individual manufacturers’ CAFE values each year, and submits these values to 

NHTSA. 

EPA is proposing footprint-based CO2 standards for cars and light trucks. EPA 

believes that this program design has the potential to promote CO2 reductions across a broad 

range of vehicle manufacturers, while simultaneously accounting for other important societal 

objectives cognizable under section 202 (a) such as consumer choice and vehicle safety. EPA 

believes a footprint-based system will also provide a more level playing field among 

manufacturers, as all models with similar size will have the same CO2 emission targets, across 

all manufacturers. 

In 2007, EPA evaluated several vehicle attributes on which to base proposed CO2

standards for both cars and light trucks: footprint, curb weight, engine displacement, interior 
Draft Regulatory Impact Analysis 

3-8 

volume, and passenger carrying capacity. All of these attributes have varied advantages and 

disadvantages. EPA’s evaluation centered on three primary criteria (all of which reflect 

factors relevant under section 202 (a)). 1) Correlation with tailpipe CO2 emissions. Since 

emissions of CO2 are controlled, there must be a reasonable degree of correlation from a 

technical perspective between a proposed attribute and vehicle CO2 emissions performance. 

2) The relationship between the attribute and potential CO2reducing technologies. In order to 

promote emissions reductions, choice in technology for the manufacturers, and cost-effective 

solutions, it is important that an attribute not discourage the use of important CO2 control 

strategies. 3) How much the attribute would encourage compliance strategies that tend to 

circumvent the goal of CO2 reduction. EPA believes that it is important to choose an attribute 

that minimizes the risk that manufacturers would change the magnitude of the attribute as a 

method of compliance. 4) The consistency of the attribute with existing or proposed 

regulations. EPA does not want to create a program that competes with others that 

accomplish similar goals. The 2007 analysis examines potential attributes against these 

criteria and is outlined below. 

3.2.1 “Footprint” as a vehicle attribute 

EPA is proposing to base the individual manufacturers fleetwide CO2 standards on the 

vehicle footprint attribute. Footprint is defined as a vehicle’s wheelbase multiplied by 

average track width. In other words, footprint is the area enclosed by the points at which the 

wheels meet the ground. 

In 2006, NHTSA adopted footprint as the basis for fuel economy standards in its 

Reformed CAFE program for light trucks, and in 2008, the agency extended this program 

structure to regulate passenger cars for MY 2011 and beyond. NHTSA used projected sales, 

footprint, and mpg data from automakers’ product plans, along with information on the cost 

and effectiveness of fuel economy technologies, to create a footprint versus fuel economy 

curve shown below in Figure 3-1 for cars and Figure 3-2 for trucks that establishes fuel 

economy targets for every model’s footprint value. Chapter V of NHTSA’s RIA for the MY 

2011 CAFE program contains more detailed information how the MY 2011 car and truck 

curves were generated. 
Technical Basis of the Standards 

3-9 

NHTSA Final MY 2011 Standards for Cars and Trucks

20

22

24

26

28

30

32

34

36

38

40

35 40 45 50 55 60 65 70 75

Footprint (ft2

)

MPG

Figure 3-1 NHTSA Reformed CAFE Curve for MY 2011 Cars 
Draft Regulatory Impact Analysis 

3-10 

NHTSA Final MY 2011 Standards for Cars and Trucks

20

22

24

26

28

30

32

34

36

38

40

35 40 45 50 55 60 65 70 75

Footprint (ft2

)

MPG

Figure 3-2 NHTSA Reformed CAFE Curve for MY 2011 Trucks 

The overall fleet-wide fuel economy compliance value for an individual manufacturer 

is then calculated at the end of the model year by a sales-weighted, harmonic average of the 

fuel economy targets for all models sold by that manufacturer. In the rulemaking process, 

NHTSA also considered weight, towing capacity, and four wheel drive capability as 

alternative attributes, but rejected them in favor of footprint.5

 

EPA evaluated footprint as the attribute for setting vehicle CO2 standards based on the 

four criteria outlined above. 

3.2.1.1 Correlation to tailpipe CO2 emissions 

Figure 3-3 and Figure 3-4 describe the relationship of tailpipe CO2 emissions and 

vehicle footprint. These figures were generated using the manufacturer’s 2007 confidential 

product plans, the most current projections at the time of the analysis. EPA has since received 

new product plans and developed a new baseline dataset from publicly available information. 

However, EPA has not redone the analysis below with this new data as the general trends are 

not expected to have changed. 
Technical Basis of the Standards 

3-11 

The first plot describes the model year 2007 car fleet and the second plot describes the 

model year 2007 truck fleet. The circles represent the sales volume of a particular model, 

where a larger circle corresponds to higher sales projection and a smaller circle corresponds to 

a lower sales projection. In order to determine how closely footprint and CO2 emissions were 

correlated, a linear least-squares regression was performed for cars and trucks separately. It 

should be noted that NHTSA used non-sales-weighted minimum absolute difference (MAD) 

regressions to develop the slopes of the proposed fuel economy and CO2 emission standards. 

The reader is referred to the preamble to the proposed rule for a discussion of the reasons for 

use of non-sales-weighted MAD regressions for this purpose. 

y = 8.46x - 89.866

R2

 = .283

100

150

200

250

300

350

400

450

500

36 38 40 42 44 46 48 50 52 54 56

Footprint (ft2

)

CO2 (g/mi)

Figure 3-3 Model Year 2007 Cars; Sales-weighted Linear Regression of CO2 Tailpipe Emissions and 

Footprint 
Draft Regulatory Impact Analysis 

3-12 

y = 4.172x + 170.17

R2

 = .331

150

250

350

450

550

650

750

35 40 45 50 55 60 65 70 75 80 85

Footprint (ft2

)

CO2 (g/mi)

Figure 3-4 Model Year 2007 Trucks; Sales-weighted Linear Regression of CO2 Tailpipe Emissions and 

Footprint 

As illustrated in the above figures, the R2

 values for model year 2007 cars and trucks 

are 0.283 and 0.331 respectively (both statistically significant to a confidence level greater 

than 99%), indicating that there is a non-random correlation to CO2 emissions. As vehicle 

size increases, its CO2 emissions tend to increase. 

3.2.1.2 Relationship with CO2-reducing strategies 

The footprint attribute would encourage all CO2 control strategies with the exception 

of vehicle downsizing. All other things being equal, vehicle downsizing tends to correspond 

to lower vehicle weight, which results in lower CO2 emissions. However, smaller vehicles 

would have smaller footprints and would be subject to lower, more stringent, CO2 emissions 

targets, discouraging downsizing as a compliance strategy. Also, absent other design 

changes, decreasing vehicle size could reduce vehicle safety for that vehicle's driver, 

especially for those vehicles less than 4000 pounds.6

 Thus, the fact that footprint discourages 

vehicle downsizing is viewed by many safety advocates as a positive aspect. This continues 

to be an important factor in NHTSA’s adoption of footprint in its Reformed CAFE program. 
Technical Basis of the Standards 

3-13 

A footprint attribute also would not discourage the use of lightweight materials, as a 

lighter vehicle with no change in footprint would more easily comply with its CO2 target. 

Therefore, in choosing the footprint attribute, the use of lightweight material would remain a 

viable compliance option, an important factor as lightweight materials can simultaneously 

reduce mobile CO2 emissions and improve vehicle safety. NHTSA came to the same 

conclusion in its Reformed CAFE rulemaking.7

 Though there can be a trend between weight 

and size, EPA is not equating the two. Moreover, EPA is assuming that manufacturers can 

and will lightweight their vehicles at a given footprint level as a potential compliance strategy. 

3.2.1.3 Sensitivity of CO2 control to compliance-related vehicle adjustments 

Depending on the attribute, manufacturers may find it more economically attractive to 

comply in a way that tends to compromise the expected emission reduction benefits of the 

program. Specifically, a manufacturer would have the opportunity to increase its average 

fleet footprint over time in order to comply with a less stringent standard, which would 

circumvent the CO2 reduction goals of the program. However, major changes in a vehicle’s 

footprint typically require a substantial redesign of the vehicle, which typically occurs every 

5-7 years. NHTSA made this same finding in the Reformed CAFE rulemaking.8

 While 

definitive historical footprint data is not available, EPA believes that footprint has grown 

more modestly in the past than many other attributes. 

3.2.1.4 Consistency with other existing or proposed regulatory programs 

EPA and NHTSA have coordinated closely in developing parallel GHG and MPG 

standards in order to avoid creating a “patchwork” of regulations. Since NHTSA has in 

recent history used footprint as the basis for its CAFE program and is proposing to continue 

using this metric, footprint remains the simplest, most natural option with respect to the goal 

of avoiding excessive regulatory burden on the manufacturers. 

Under the Clean Air Act, the State of California may petition EPA for the authority to 

create more stringent mobile source emissions regulations at the state level. EPA has granted 

California this privilege and the California program outlined does not utilize the footprint (or 

any) attribute; instead the regulatory structure is based on a universal (or unreformed) 

standard. Despite differences in the structure of the standards, the EPA federal program is 

expected to have an equivalent stringency when compared to the California program, thus 

making it a 50-state program. In order to account for early AC credits offered by the 

California program, EPA has also chosen to adopt a very similar credit system outlined in 

Chapter 2 of the RIA, which offers an additional layer of consistency. 
Draft Regulatory Impact Analysis 

3-14 

3.2.2 Alternative Attributes 

Some manufacturers have suggested using a vehicle’s curb weight for an attributebased standard. Curb weight is defined in EPA regulations (CFR 86.1803-01) as the actual or 

estimated weight of the vehicle with all standard equipment, plus the fuel weight at nominal 

tank capacity, plus the weight of optional equipment. Figure 3-5 and Figure 3-6 below show 

plots of tailpipe CO2 emissions versus curb weight for 2007 car and truck models respectively, 

where circle size indicates the sales volume of each model. 

y = 0.0885x + 6.764

R2 = .582

100

150

200

250

300

350

400

450

500

2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400

Curb Weight (lbs)

CO2 (g/mi)

Figure 3-5 Model Year 2007 Cars; Sales-weighted Linear Regression of CO2 Tailpipe Emissions and Curb 

Weight 
Technical Basis of the Standards 

3-15 

y = 0.0593x + 126.85

R2

 = .521

150

250

350

450

550

650

750

3000 3500 4000 4500 5000 5500 6000 6500 7000 7500

Curb Weight (lbs)

CO2 (g/mi)

Figure 3-6 Model Year 2007 Trucks; Sales-weighted Linear Regression of CO2 Tailpipe Emissions and 

Curb Weight 

For both cars and trucks, curb weight has a relatively high correlation with tailpipe 

CO2 emissions. A sales-weighted linear least squares regression determined R2

 values of 

0.582 for cars and 0.521 for trucks, indicating a substantial relationship of the current fleet’s 

curb weight and CO2 emissions. 

Historically, some vehicle safety advocates have preferred weight for an attributebased standard since a standard with a steep relationship with weight discourages downweighting. However, with recent advances in strong, lightweight materials, occupant safety is 

not necessarily compromised by a reduction in vehicle weight.9

 In fact, these studies have 

shown that a vehicle’s size is a more important factor than weight in its effect on occupant 

safety. In a weight-based attribute system, a lower weight would correspond to a more 

stringent CO2 standard. While this would discourage downsizing as a compliance strategy, 

it’s important to recognize that weight as an attribute for determining tailpipe CO2 standards 

would discourage the use of lightweight materials, even though advanced lightweight 

materials could simultaneously reduce CO2 emissions and improve vehicle safety. 

Furthermore, since a vehicle’s weight is much easier to change than most other 

attributes, it is more likely that manufacturers could add weight to their vehicles in order to be 

subject to and comply with a less stringent standard. This potential is reinforced by the 

relatively high rate of growth of vehicle weight; it has grown 1.0 – 1.5% per year since the 
Draft Regulatory Impact Analysis 

3-16 

late 1980s.10 This development would have negative environmental consequences by 

increasing overall CO2 emissions, contrary to the chief goal of section 202 (a) of the Act. 

EPA also examined engine displacement as a potential attribute for determining 

manufacturer CO2 standards. Engine displacement is defined as the volume swept as the 

piston moves from top dead center to bottom dead center. Figure 3-7 and Figure 3-8 below 

contain sales-weighted linear regression plot of tailpipe CO2 emissions and engine 

displacement for 2007 cars and trucks, respectively. 

y = 45.333x + 171.53

R2 = .667

100

150

200

250

300

350

400

450

500

01234567

Engine Displacement (L)

CO2 (g/mi)

Figure 3-7 Model Year 2007 Cars; Sales-weighted Linear Regression of CO2 Tailpipe Emissions and 

Engine Displacement. 
Technical Basis of the Standards 

3-17 

y = 45.094x + 217.45

R2

 = .619

150

250

350

450

550

650

750

1234567

Engine Displacement (L)

CO2 (g/mi)

Figure 3-8 Model Year 2007 Trucks; Sales-weighted Linear Regression of CO2 Tailpipe Emissions and 

Engine Displacement 

Engine displacement correlates well to tailpipe emissions, with R2

 values of 0.667 for 

cars and 0.619 for trucks. This is because increasing engine displacement typically increases 

the amount of fuel burned per cycle. 

EPA believes that a standard based on engine displacement does not guarantee any 

environmental benefit because of the disincentive to add certain CO2-reducing technologies 

and the potential for manufacturers to adjust the sales of higher-displacement models 

regardless of whether or not it reflects market demand. Hypothetically, a model could have 

three trim lines with three different displacements: A 4-cylinder 2.0L Turbo, a 4-cylinder 

2.5L, and a 6-cylinder 3.0L. Since these models would have three standards ranging from 

most to least stringent, correspondingly, this type of standard would be a disincentive to sell 

models with smaller engines or turbochargers. These strategies can dramatically reduce CO2

emissions (See RIA Section on Tech Feasibility) and are increasingly prevalent in the 

European market. Thus EPA believes that the use of engine displacement for establishing 

CO2 tailpipe standards will undermine readily achievable and feasible reductions of CO2

emissions. 
Draft Regulatory Impact Analysis 

3-18 

EPA also examined interior volume and occupant capacity as potential attributes 

because they characterize vehicle utility well. Increasing interior volume creates more space 

for people and cargo, and increasing occupant capacity creates the potential to carry more 

people, both important factors consumers consider when purchasing a new vehicle. Figure 

3-9 below contains a plot of interior volume and tailpipe CO2 for model year 2007 cars. 

MY 2007 Cars: Tailpipe CO2 Emissions by Interior Volume R2

 = 0.0036

100

200

300

400

500

600

700

50 70 90 110 130 150 170 190

Interior Volume (ft3

)

Tailpipe CO2 (g/mi)

Figure 3-9 Model Year 2007 Cars; Linear Trend of CO2 Tailpipe Emissions and Engine Displacement 

EPA confirmed that interior volume is not at all correlated to vehicle CO2 emissions 

with a R2

 value of 0.0036 for cars. The correlation of interior volume and tailpipe CO2 is 

worse for light trucks by definition, since cargo space for pickup trucks is a separate exterior 

bed. Thus, it does not make sense to have a CO2 standard for light trucks that is based on 

interior volume, since pick-up trucks would be required to meet a stricter CO2 standard than 

SUVs and minivans, which are typically regulated in the general “truck” category. For these 

reasons, EPA is not proposing interior volume for the standard. 

Alternatively, occupant capacity does not share the same safety implications as 

interior volume. Furthermore, since it is difficult to game and does not discourage the use of 

any CO2 -reducing technologies, there is significant potential for CO2 improvement. Figure 

3-10 and Figure 3-11 below illustrate the breakdown of the model year 2007 fleet in terms of 

occupant capacity. 
Technical Basis of the Standards 

3-19 

Model Year 2007 Cars: Percentage of Sales by Occupant Capacity

2.2%

84.0%

5.7%

8.1%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

2456

Number of Seats

Percentage

Figure 3-10 Model Year 2007 Cars; Percentage of Sales by Occupant Capacity 
Draft Regulatory Impact Analysis 

3-20 

MY 2007 Cars: Range of Tailpipe CO2 Emissions by Occupant Capacity

0

100

200

300

400

500

600

700

1234567

Number of Occupants

Tailpipe CO2 (g/mi)

Figure 3-11 Model Year 2007 Cars; Range of Tailpipe CO2 Emissions by Occupant Capacity 

However, occupant capacity and CO2 emissions do not relate well. Since 84% of the 

2007 car fleet has 5 seats, an occupant-based standard would essentially result in a universal 

standard for a majority of vehicles. Since the car models falling into the 5-seat category have 

a tailpipe CO2 range of 133 to 472 g/mi, an occupancy-based standard would negate the 

benefits from relative equity of the attribute-based system to full line manufacturers. 

3.2.3 EPA Selection of the Footprint Attribute 

EPA has considered a range of potential vehicle attributes that could be used to set 

CO2 standards. To summarize key results from the 2007 analysis, interior volume and 

passenger carrying capacity have extremely poor correlation with fuel economy, and EPA is 

not proposing them for that reason. The three remaining attribute options—footprint, curb 

weight, and engine displacement—are all reasonable choices in terms of correlation with CO2

emissions levels, with weight having the best correlation to CO2 emissions levels. However, 

it should be noted that correlation is not the primary deciding factor for the selection of an 

attribute. One could easily get an excellent correlation by choosing a function that combines 

the effects of weight, displacement, N/v ratio (engine speed to vehicle speed ratio at top gear), 

and frontal area (as a product with the aerodynamic coefficient). There are many other, but 

these are the four variables that most define a vehicle’s fuel economy11,12 The choice of an 

attribute is not only an engineering decision, it also a policy decision. It is linked with the 

outcomes that are desired in a future fleet. 
Technical Basis of the Standards 

3-21 

 With respect to the remaining criteria, EPA believes footprint is clearly superior to 

both weight and engine displacement. Footprint does not inherently discourage any key CO2

control strategies (except for vehicle downsizing), while weight would discourage the use of 

lightweight materials. Engine displacement would discourage engine downsizing with 

turbocharging, a strategy increasingly popular in the United States and Europe. Footprint is 

somewhat less susceptible to modifications for compliance, since major changes would 

generally require a significant platform redesign; in contrast, it is easier for manufacturers to 

change weight and engine displacement. 

EPA notes that the footprint attribute also correlates well with the "utility" or 

"usefulness" of the vehicle to the consumer. Larger footprints amount to more space inside 

the vehicle to carry passengers or cargo, which are important considerations for consumers. 

Thus, it is an additional benefit that the footprint-based approach would not discourage 

changes to vehicle designs that can provide more utility to consumers. EPA also recognizes 

that if footprint is used for the vehicle CO2 standards then the form of the standards would be 

compatible with NHTSA’s use of footprint in their Reformed CAFE program. EPA requests 

comment on the proposed selection of the footprint attribute for establishing manufacturerspecific CO2 standards. 

For these reasons, EPA therefore believes that the footprint attribute is the best choice 

of the attributes discussed, from both an engineering as well as from a public policy 

standpoint. EPA therefore proposes to use footprint in the CO2 standard-setting process for 

this rule. 

EPA is proposing to implement the footprint attribute in the proposed CO2 control 

program via a piecewise linear function. As mentioned above, this is the equivalent to the 

shape selected by NHTSA for its proposed CAFE standards for light trucks for model years 

2012-2016. The shape of this function with respect to CO2 is reflected in Figures I.D.3-3 and 

I.D.3-4 of the preamble. The difference is that it moves from low CO2 values on the left to 

high CO2 values on the right (see Figure 3-12 and Figure 3-13 below for example) due to its 

inverse relation to MPG. 
Draft Regulatory Impact Analysis 

3-22 

200

250

300

350

400

30 35 40 45 50 55 60 65 70 Footprint (sq feet)

CO2 (grams per mile)

2012

2016

`

Figure 3-12 CO2 (g/mi) Car standard curves 

200

250

300

350

400

30 35 40 45 50 55 60 65 70 Footprint (sq feet)

CO2 (grams per mile)

2012

2016

Figure 3-13 CO2 (g/mi) Truck standard curves 
Technical Basis of the Standards 

3-23 

Implementing the proposed CO2 emission standards in this manner provides consistency with 

NHTSA’s proposed CAFE standards. 

Other forms of a footprint-based CO2 standard are possible. Examples are a logistic 

curve, simple straight line, a line which levels out at a certain point to discourage vehicle 

upsizing, etc. Section II of the preamble as well as Chapter 2 of the draft joint TSD contains 

more information on how EPA defined the piecewise linear CO2 target function. 

3.3 Supplemental Analysis of Relative Car and Truck Standards 

The methodology used to set the standards, and thus, the relative stringency of the car 

and truck standards is described in Chapter 2 of the draft Joint TSD. The car and truck 

standards were set based on achieved levels of car and truck fuel economy from NHTSA’s 

Volpe Model under conditions where estimated net social benefits were maximized, while the 

application of strong hybrid and diesel technology was excluded. These achieved levels were 

then adjusted upwards arithmetically until the combined car-truck fleet met the CO2 levels 

described in Section 3.1 above. EPA and NHTSA worked jointly in that analysis and EPA 

believes it is a reasonable basis for determining the relative car-truck stringency for the 

proposed GHG standards. 

In this section, a few alternative methods to setting this relative stringency are 

investigated. These methods use the OMEGA model, though it is expected that the results 

would be similar if the Volpe Model was used. EPA’s OMEGA model and its use in support 

of this proposed rule is described in Chapter 4 of this draft RIA. 

In performing these runs of the OMEGA model, the technology packages were 

removed which added either hybrid or diesel technology. This was done because the CO2 

reduction required to meet the overall level of CO2 emissions being proposed for 2016, 250 

g/mi, is generally not requiring significant levels of either hybrid or diesel technology when 

the potential for A/C credits is considered. This is the same approach that was used in the 

Volpe modeling used to develop the car and truck standards as described in Chapter 2 of the 

draft Joint TSD. The technology penetration of the other technologies was limited as 

described in Chapter 1 for MY 2016; 100% for the technologies included in package 1 for 

each vehicle type and 85% for the more significant technologies (any technology package 

number 2 or higher). In order to be comparable to the Volpe modeling, A/C related 

technologies were not included. Thus, the CO2 emission target was 261 g/mi in 2016. Fuel 

prices and the value of externalities were the same as those used to project the benefits from 

the proposal. 

As described in greater detail in Chapter 4, the OMEGA model applies technology 

incrementally. It determines which vehicle receives the next step of control using the 

manufacturer-based net cost effectiveness metric. This metric includes the cost of the 

technology, the value of the fuel savings which accrues from the CO2 technology over a 

specified time period (here, 5 years) and the degree of CO2 emission reduction. This ranking 
Draft Regulatory Impact Analysis 

3-24 

process includes the decision of whether to apply the next level of control to a car or a truck. 

This allows the evaluation of car and truck CO2 control simultaneously. 

In the first set of OMEGA runs used to evaluate relative car-truck stringency, all 

manufacturers’ vehicles were combined into a single fleet. Determining manufacturerspecific CO2 standards or levels of control requires some initial assumption of relative car 

and truck stringency. Modeling the industry as one, single fleet avoids this. It also makes the 

analysis more technical in nature and focuses on the technical capability of the industry to 

reduce car and truck CO2 emissions efficiently, as manufacturer distinctions are eliminated. 

The disadvantage is that it does not reflect the fact that manufacturers vehicles differ in their 

fundamental level of CO2 emissions and therefore, manufacturers differ in the projected level 

of technology needed to meet the same footprint-based standard. With this simplification, a 

single run of the OMEGA model can provide an indication of the relative potential to control 

car and truck CO2 emissions. 

We ran the OMEGA model with a CO2 emission standard which was beyond the 

capability of the technology available (i.e., maximum technology). The combined level of car 

plus truck CO2 emissions was determined, as well as for cars and trucks separately. The 

overall level of control was relaxed until net societal benefits were maximized. The benefits 

quantified included reduced externalities related to crude oil imports, upstream emissions, 

refueling time and CO2 emission reductions. They also included costs and benefits associated 

with increased VMT due to the fuel economy rebound effect (e.g., vehicle emissions, noise, 

congestion, value of additional driving, etc.) CO2 was valued at $20 per ton in 2007 and a 

3% per annum discount rate was used. Finally, the overall CO2 emissions was increased in 

several steps from the maximum net benefit level to evaluate how relative car and truck 

emissions changed with the overall level of stringency. The results of this analysis are 

summarized in Table 3-9. 

Table 3-9 Relative Car and Truck CO2 Emissions At Various Levels of CO2 Control – Single Industrywide 2016 Fleet (Excludes Impact of A/C Technology) 

Car CO2 

(g/mi) 

Truck CO2 

(g/mi) 

Combined CO2 

(g/mi) 

Ratio of Truck/Car 

CO2 

Maximum Application of 

Technology 209.4 286.6 235.3 1.37 

Maximum Net Societal Benefits 210.1 286.6 235.8 1.36 

+5 g/mi CO2 214.8 291.7 240.6 1.36 

+10 g/mi CO2 218.6 298.3 245.3 1.36 

+15 g/mi CO2 222.0 305.5 250.0 1.38 

+20 g/mi CO2 222.2 318.5 254.5 1.43 

+25 g/mi CO2 226.0 325.2 259.2 1.44 

As can be seen, applying all the non-hybrid and non-diesel technology achieved an 

overall level of CO2 control of 235 g/mi. This is equivalent to a fuel economy of 37.8 mpg, 

since the use of diesel engines in only that in the reference fleet. (If A/C-related CO2 

emission reduction of 11 g/mi were subtracted from this figure, it would decrease to 224 g/mi, 

equivalent to 39.6 mpg.) The ratio of car to truck CO2 emissions at this overall level of CO2 

emissions is 1.37. Relaxing this level until net societal benefits reach their maximum only 

increased CO2 emissions by 0.5 g/mi (equivalent to a decrease in fuel economy of 0.1 mpg). 
Technical Basis of the Standards 

3-25 

This indicates that net incremental cost of nearly all the non-hybrid, non-diesel technology 

packages are less than the societal benefits provided. The ratio of car to truck CO2 emissions 

at this overall level of CO2 emissions decreases slightly to 1.36. The ratio for the proposed 

truck and car standards in 2016 is 1.35 (302/224), or nearly identical. 

As the overall level of CO2 control is relaxed, the ratio of truck to car emissions 

increases. This indicates that, on the increment, the least cost effective steps of control were 

applied primarily to trucks and not cars. EPA’s and NHTSA’s methodology for setting the 

relative stringency for the car and truck standards in 2012 through 2016 began with the car 

and truck CO2 levels where estimated social benefits were maximized and increased the CO2 

levels of both cars and trucks by the same increment until the combined CO2 level was 261 

g/mi. Because the cars emit less than trucks, these shifts upward increase car emissions by a 

greater percentage than truck emissions. Increasing the overall level of CO2 emissions based 

on the relative cost effectiveness of technology would increase truck emissions by a greater 

percentage than car emissions. 
Draft Regulatory Impact Analysis 

3-26 

References 

All references can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472.

 1

 Energy Information Administration. Annual Energy Outlook 2009. 

http://www.eia.doe.gov/oiaf/aeo/index.html

2

 NHTSA Model Year 2011 Rule. RIN 2127-AK29. Average Fuel Economy Standards. Passenger Cars and 

Light Trucks. Model Year 2011. 

3

 NHTSA Model Year 2011 Rule. RIN 2127-AK29. Average Fuel Economy Standards. Passenger Cars and 

Light Trucks. Model Year 2011. 

4

 NHTSA Model Year 2011 Rule. RIN 2127-AK29. Average Fuel Economy Standards. Passenger Cars and 

Light Trucks. Model Year 2011. 

5

 See generally 71 FR at 17595-96. 

6

 National Academy of Sciences, “Effectiveness and Impact of Corporate Average Fuel Economy (CAFE) 

Standards,” National Academy Press, Washington, DC, 2002. Available for online viewing or hard copy 

purchase from the National Academy Press at http://books.nap.edu/openbook.php?isbn=0309076013. 

7

 71 FR at 17620-21; see also 2002 NAS Report at 24. 

8

 71 FR at 17613. 

9

 71 FR at 17596; 2002 NAS Report at 24. 

10 Light-Duty Automotive Technology and Fuel Economy Trends: 1975 through 2007," U.S. Environmental 

Protection Agency, EPA420-S-07-001, September 2007, "http://www.epa.gov/otaq/fetrends.htm 

11 Nam, E.K., Giannelli, R, Fuel Consumption Modeling of Conventional and Advanced Technology Vehicles 

in the Physical Emission Rate Estimator (PERE), EPA document number EPA420-P-05-001, 2004

12Guidelines for Analytically Derived Fuel Economy. March 11, 2004 

http://www.epa.gov/otaq/cert/dearmfr/ccd0406.pdf
Results of Proposed and Alternative Standards 

4-1 

CHAPTER 4: Results of Proposed and Alternative Standards 

4.1 Introduction 

There are many ways for a manufacturer to reduce CO2 emissions from any given 

vehicle during a redesign. A manufacturer can choose from a myriad of CO2 reducing 

technologies and can apply one or more of these technologies to some or all of its 

vehicles. Thus, for a variety of levels of CO2 emissions control, there are an almost 

infinite number of technology combinations which produce the desired CO2 reduction. 

EPA has created a new vehicle model, the Optimization Model for Emissions of 

Greenhouse gases from Automobiles (OMEGA) in order to make a reasonable estimate 

of how manufacturers will add technologies to vehicles in order to meet a fleet-wide CO2

emissions level. 

4.2 Model Inputs 

OMEGA utilizes four basic sets of input data. The first is a description of the 

vehicle fleet. The key pieces of data required for each vehicle are its manufacturer, CO2

emission level, fuel type, projected sales and footprint. The model also requires that each 

vehicle be assigned to one of the 19 vehicle types, which tells the model which set of 

technologies can be applied to that vehicle. Chapter 1 of the TSD contains a description 

of how the vehicle reference fleets were created for modeling purposes, and includes a 

discussion on how EPA defined the 19 vehicle types. In addition, the degree to which 

each vehicle already reflects the effectiveness and cost of each available technology in 

the 2008 baseline fleet must also be input. This prevents the model from adding 

technologies to vehicles already having these technologies in the baseline. It also avoids 

the situation, for example, where the model might try to add a basic engine improvement 

to a current hybrid vehicle. Section 4.2.1 of this Draft Regulatory Impact Analysis 

(DRIA) contains a detailed discussion of how EPA accounts for technology present in the 

baseline fleet in OMEGA. 

The second type of input data used by the model is a description of the 

technologies available to manufacturers, primarily their cost and effectiveness. Note that 

the five vehicle classes which determine the individual technology cost and effectiveness 

values are not explicitly used by the model; instead, the costs and effectiveness used by 

the model are associated with each vehicle package, and are based on their associated 

vehicle types (of 19). This information was described in Chapter 1 of this DRIA and 

Chapter 3 of the Draft Joint TSD. In all cases, the order of the technologies or 

technology packages for a particular vehicle type is designated by the model user in the 

input files prior to running the model. Several criteria can be used to develop a 

reasonable ordering of technologies or packages. These are described in Chapter 1 of the 

Draft RIA. 

The third type of input data describes vehicle operational data, such as annual 

scrap rates and mileage accumulation rates, and economic data, such as fuel prices and 

discount rates. These estimates are described in chapter 4 of the Draft Joint TSD. 
Draft Regulatory Impact Analysis 

4-2 

The fourth type of data describes the CO2 emission standards being modeled. 

These include the CO2 emission equivalents of the 2011 MY CAFE standards and the 

proposed CO2 standards for 2016. As described in more detail in Chapter 2 of this DRIA 

and briefly in section 4.2.1 below, the application of A/C technology is evaluated in a 

separate analysis from those technologies which impact CO2 emissions over the 2-cycle 

test procedure. For modeling purposes, EPA applies this AC credit by adjusting 

manufacturers’ car and truck CO2 targets by an amount associated with EPA’s projected 

use of improved A/C systems, as discuss in Section 4.2.1, below. 

4.2.1 Representation of the CO2 Control Technology Already Applied to 

2008 MY Vehicles 

The market data input file utilized by OMEGA, which characterizes the vehicle 

fleet, is designed to account for the fact that vehicles may be equipped with one or more 

of the technologies available in general to reduce CO2 emissions. As described in 

Chapter 1 of this RIA, EPA decided to apply technologies in packages, as opposed to one 

at a time. However, 2008 vehicles were equipped with a wide range of technology 

combinations, many of which cut across the packages. Thus, EPA developed a method to 

account for the presence of the combinations of applied technologies in terms of their 

proportion of the EPA packages described in Chapter 1. This analysis can be broken 

down into four steps. 

The first step is to develop a list of individual technologies which are either 

contained in each technology package, or would supplant the relevant portion of each 

technology package (e.g., the engine, the transmission, etc.). For example, variable 

intake valve timing would be associated with a downsized, turbocharged, direct injection 

engine. Thus, the effectiveness and cost of variable intake valve timing would be 

considered to be already present for any technology package which included either 

variable intake valve timing or included an engine technology which provided greater 

effectiveness. The reverse case would be an example of a technology which would 

supplant another technology. If a vehicle already had a downsized, turbocharged, direct 

injection engine, the effectiveness and cost of this technology would be considered to be 

already fully present when evaluating the application of a technology package which 

included variable intake valve timing or any other engine technology up to and including 

a downsized, turbocharged, direct injection engine. In either case, the effectiveness and 

cost present on the 2008 MY vehicle would be limited to the effectiveness and cost of the 

engine technology This would allow the application of non-engine related technologies 

also included in that package (e.g., an improved transmission) to still be applied. 

A specific example would be a 2008 MY vehicle falling into EPA vehicle type 1 

equipped with a dry DCT. A dry DCT is added as part of EPA’s technology package 

number 3 for vehicle type 1. Thus, the effectiveness and cost of a dry DCT would be 

considered to be already present when applying the effectiveness and cost of package 3 to 

this vehicle. If the dry DCT contributed to 50% of the total effectiveness and 40% of the 

cost of package 3 over package 2 and 40% of the cost of package 3 over package 2 for 

this vehicle, then these percentages would be included in the market data file for this 

vehicle. If the level of CO2 control led to the application of technology package 3 to this 
Results of Proposed and Alternative Standards 

4-3 

vehicle in a run of the OMEGA model, the model would only apply 50% of the 

effectiveness of package 3 to this vehicle and 60% of the cost of this package. 

If two consecutive technology packages both contain a dry DCT, packages 3 and 

4, for example, the model user does not need to declare it as technology already present 

in the baseline. Instead, the benefit of package 4 is due to engine-related technology is 

considered incremental to package 3 and is contained in the technology input file. When 

applying package 4 to this vehicle, the OMEGA model will apply its full incremental 

effectiveness and cost. The same would be true for packages which replace a dry DCT 

with a hybrid technology equipped with variable valve timing and a 6-speed automatic 

transmission. The cost and effectiveness of variable valve timing would be considered to 

be already present for any technology packages which included the addition of variable 

valve timing or technologies which went beyond this technology in terms of engine 

related CO2 control efficiency. 

Since vehicle models are grouped into vehicle types for technology addition, and 

there are relatively few vehicle types compared to the number of vehicle models 

analyzed, there may be special cases when the applicable technology packages are less 

effective than baseline technologies; EPA therefore limits the applicability of the relevant 

technology packages to the affected vehicle models by adjusting the cost and 

effectiveness reflected in the baseline by the same method described above. An example 

of a single technology which supplants several technologies would be a 2008 MY vehicle 

which was equipped with a diesel engine. The effectiveness of this technology would be 

considered to be present for technology packages which included small improvements to 

a gasoline engine, since the resultant gasoline engine would otherwise accrue technology 

packages which are not as effective at reducing CO2 than the baseline diesel engine. 

However, if these packages which included improvements also included improvements 

unrelated to the engine, like transmission improvements, only the engine related portion 

of the package already present on the vehicle would be considered. The transmission 

related portion of the package’s cost and effectiveness would be allowed to be applied in 

order to comply with future CO2 emission standards. 

Six technologies were considered to be contained in all technology packages 

available for all 19 vehicle types: low viscosity lubrication, improved engine friction, low 

rolling resistance tires, high efficiency accessories, electric power steering and improved 

automatic transmission controls and lock-up. The total effectiveness and cost estimates 

for every technology package described in Chapter 1 includes the effectiveness and cost 

of these five technologies. Thus, their presence on a 2008 MY vehicle must be deducted 

from the effectiveness of any package added in the modeling. 

All the packages described in Chapter 1 which are numbered 2 or higher (i.e., all 

packages other than the initial package available to each vehicle type) contain at least 

dual cam phasing and a 6-speed automatic transmission. Thus, the followed technologies 

were considered to be contained in all technology packages numbered 2 and above for all 

19 vehicle types: intake valve timing, coupled cam phasing, dual cam phasing, 6-speed 

(or higher) automatic or manual transmission, or a continuously variable transmission. In 

addition, the following technologies supplant either dual cam phasing or a 6-speed 
Draft Regulatory Impact Analysis 

4-4 

automatic transmission: variable valve lift and timing, cylinder deactivation, diesel 

combustion, dual clutch transmission, and IMA, power-split and 2-mode hybridization. 

Thus, the effectiveness and cost of these technologies were also included when 

determining the percentages of the effectiveness and cost of each package number 2 or 

higher which was already utilized on each 2008 MY vehicle. 

All the packages described in Chapter 1 which are numbered 2 or also include 

conversion to direct injection gasoline combustion, except for package 2 for vehicle type 

1. Thus, the effectiveness and cost of direct injection gasoline combustion was also 

included when determining the percentages of the effectiveness and cost of each package 

number 2 or higher which was already utilized on each 2008 MY vehicle, with the 

exception of package number 2 for vehicle type 1. 

Table 4-1 depicts the packages which first turbocharge an engine. 

Table 4-1 Technology Packages Which Initially Include Turbocharging 

Vehicle 

Type 

Technology 

Package 

Vehicle 

Type 

Technology 

Package 

1 4 12 5 

3 4 13 5 

4 2 14 5 

5 4 15 4 

6 4 16 3 

7 5 17 5 

8 5 18 5 

9 4 19 5 

10 5 

Thus, the effectiveness and cost of turbocharging was included when determining 

the percentages of the effectiveness and cost of each package shown in Table 4-1 or 

higher within each vehicle type which was already utilized on each 2008 MY vehicle. 

Table 4-2 depicts the packages which first add start-stop technology to a vehicle. 
Results of Proposed and Alternative Standards 

4-5 

Table 4-2 Technology Packages Which Initially Add Start-Stop 

Vehicle 

Type 

Technology 

Package 

Vehicle 

Type 

Technology 

Package 

1 3 11 4 

2 3 12 4 

3 3 13 4 

4 3 14 4 

5 3 15 3 

6 3 16 3 

7 4 17 4 

8 4 18 4 

9 4 19 4 

10 4 

Thus, the effectiveness and cost of start-stop technology was included when 

determining the percentages of the effectiveness and cost of each package shown in Table 

4-2 or higher within each vehicle type which was already utilized on each 2008 MY 

vehicle. 

The second step in this process is to determine the total cost and CO2 

effectiveness of the technologies already present and relevant to each available package. 

Determining the total cost usually simply involves adding up the costs of the individual 

technologies present. In order to determine the total effectiveness of the technologies 

already present on each vehicle, the lumped parameter model described above is used. 

Because the specific technologies present on each 2008 vehicle are known, the applicable 

synergies and dis-synergies can be fully accounted for. 

The third step in this process is to divide the total cost and CO2 effectiveness 

values determined in step 2 by the total cost and CO2 effectiveness of the relevant 

technology packages. These fractions are capped at a value of 1.0 or less, since a value 

of 1.0 causes the OMEGA model to not change either the cost or CO2 emissions of a 

vehicle when that technology package is added. 

The fourth step is to combine the fractions of the cost and effectiveness of each 

technology package already present on the individual 2008 vehicles models for each 

vehicle type. For cost, percentages of each package already present are combined using a 

simple sales-weighting procedure, since the cost of each package is the same for each 

vehicle in a vehicle type. For effectiveness, the individual percentages are combined by 

weighting them by both sales and base CO2 emission level. This appropriately weights 

vehicle models with either higher sales or CO2 emissions within a vehicle type. Once 

again, this process prevents the model from adding technology which is already present 
Draft Regulatory Impact Analysis 

4-6 

on vehicles, and thus ensures that the model does not double count technology 

effectiveness and cost associated with complying with the 2011 MY CAFE standards and 

the proposed CO2 standards. 

Table 4-3 and Table 4-4 show the degree to which the baseline fleet, adjusted for 

sales in 2016, includes the effectiveness and cost of the various technology packages by 

vehicle type. 

Table 4-3 Presence of Technology on 2008 MY Vehicles In Terms of CO2 Effectiveness (Weighted 

Average Across Car and Truck Sales in 2016) 

 Technology Package Number 

Vehicle 

Type 1 2 3 4 5 6 

1 6.50% 19.70% 2.30% 0.00% N/A* N/A

2 13.20% 28.10% 12.60% N/A N/A N/A

3 11.80% 21.70% 0.50% 24.30% N/A N/A

4 2.80% 35.30% 0.00% 0.00% N/A N/A

5 11.40% 38.30% 3.70% 1.00% N/A N/A

6 2.20% 47.70% 1.60% 4.10% N/A N/A

7 8.30% 22.10% 19.40% 0.10% 0.00% 0.00%

8 0.00% 0.00% 0.00% 0.00% 0.00% N/A

9 0.50% 0.00% 0.00% 0.00% 0.00% N/A

10 0.50% 4.70% 0.60% 0.00% 0.00% N/A

11 1.40% 0.00% 0.00% 0.00% N/A N/A

12 7.50% 13.00% 2.40% 0.00% 0.00% N/A

13 22.90% 6.80% 57.40% 0.00% 0.00% N/A

14 0.00% 33.70% 0.00% 0.00% 0.00% N/A

15 0.00% 0.00% 0.00% 0.00% 0.00% N/A

16 5.60% 31.30% 3.30% 0.00% N/A N/A

17 4.00% 57.70% 9.40% 0.00% 0.00% N/A

18 19.40% 15.80% 0.00% 0.00% 0.00% N/A

19 17.80% 47.40% 0.00% 0.00% 0.00% N/A

* N/A: No such package for that vehicle type 
Results of Proposed and Alternative Standards 

4-7 

Table 4-4 Presence of Technology on 2008 MY Vehicles In Terms of Cost (Weighted Average Across 

Car and Truck Sales in 2016) 

 Technology Package Number 

Vehicle 

Type 1 2 3 4 5 6 

1 1.40% 16.50% 1.90% 0.00% N/A N/A

2 7.60% 23.20% 16.40% N/A N/A N/A

3 8.10% 15.40% 3.40% 5.70% N/A N/A

4 2.00% 31.90% 0.00% 0.00% N/A N/A

5 10.90% 22.40% 3.40% 0.20% N/A N/A

6 0.70% 33.80% 2.40% 3.00% N/A N/A

7 6.20% 19.90% 27.90% 0.20% 0.20% 0.00%

8 0.00% 0.00% 0.00% 0.00% 0.00% N/A

9 0.10% 0.00% 0.00% 0.00% 0.00% N/A

10 0.10% 2.60% 0.60% 0.00% 0.00% N/A

11 0.20% 0.00% 0.00% 0.00% N/A N/A

12 1.30% 3.10% 2.40% 0.00% 0.00% N/A

13 3.30% 2.80% 58.20% 0.10% 0.10% N/A

14 0.00% 8.70% 0.00% 0.00% 0.00% N/A

15 0.00% 0.00% 0.00% 0.00% 0.00% N/A

16 1.80% 22.90% 6.90% 0.00% N/A N/A

17 1.40% 46.90% 12.00% 9.50% 0.00% N/A

18 12.60% 11.10% 0.00% 0.00% 0.00% N/A

19 2.70% 26.60% 0.00% 0.00% 0.00% N/A

As mentioned above for the market data input file utilized by OMEGA, which 

characterizes the vehicle fleet, the modeling must and does account for the fact that many 

2008 MY vehicles are already equipped with one or more of the technologies discussed 

in the Draft TSD Chapter 3. Because EPA chose to apply technologies in packages, and 

2008 vehicles are equipped with individual technologies in a wide variety of 

combinations, accounting for the presence of specific technologies in terms of their 

proportion of package cost and CO2 effectiveness requires careful, detailed analysis. The 

first step in this analysis is to develop a list of individual technologies which are either 

contained in each technology package, or would supplant the addition of the relevant 

portion of each technology package. An example would be a 2008 MY vehicle equipped 

with variable valve timing and a 6-speed automatic transmission. The cost and 

effectiveness of variable valve timing would be considered to be already present for any 

technology packages which included the addition of variable valve timing or technologies 

which went beyond this technology in terms of engine related CO2 control efficiency. 
Draft Regulatory Impact Analysis 

4-8 

An example of a technology which supplants several technologies would be a 2008 MY 

vehicle which was equipped with a diesel engine. The effectiveness of this technology 

would be considered to be present for technology packages which included 

improvements to a gasoline engine, since the resultant gasoline engines have a lower 

CO2 control efficiency than the diesel engine. However, if these packages which 

included improvements also included improvements unrelated to the engine, like 

transmission improvements, only the engine related portion of the package already 

present on the vehicle would be considered. The transmission related portion of the 

package’s cost and effectiveness would be allowed to be applied in order to comply with 

future CO2 emission standards. 

4.2.2 Technology Package Approach 

 Consistent with its streamlined redesign cycle approach, EPA designed OMEGA 

to allow the user to add GHG-reducing technologies in packages that would reasonably 

and likely be added by manufacturers within a redesign cycle. In addition, the user can 

combine similar vehicle models into “vehicle type” groups which are likely to receive the 

same list of technology packages. For each vehicle type, the user must rank the 

technology packages in order of how OMEGA should add them to that specific vehicle 

type. This approach puts some onus on the user to develop a reasonable sequence of 

technologies. However, the model also produces information which helps the user 

determine when a particular technology or bundle of technologies might be “out of 

order”. The approach also simplifies the model’s calculations and enables synergistic 

effects among technology packages to be included to the fullest degree possible. 

 When technology is sufficiently new, or the lead time available prior to 

the end of the redesign cycle is such that it is not reasonable to project that the technology 

could be applied to all vehicle models that are of the same specific vehicle type, the user 

can limit the technology application through the use of a market penetration cap (“market 

cap”) of less than 100%. This cap can vary by redesign cycle. When a technology 

package is applied to fewer than 100% of the sales of a vehicle model due to the market 

cap, the effectiveness of the technology group is simply reduced proportionately to reflect 

the total net effectiveness of applying that technology package to that vehicle’s sales. 

Most of the technologies for the analysis conducted in this rule had a market cap of 85%, 

though hybrids were restricted to 15% for reasons described in the preamble. A small 

number of technologies had a 100% phase in cap. These include: low friction lubricants, 

electric power steering, improved accessories, and low rolling resistance tires. These 

simple to apply technologies may be implemented outside of a vehicle’s normal redesign 

schedule. 

 OMEGA does not create a new vehicle with the technology package and 

retain the previous vehicle which did not receive the technology package, splitting sales 

between the old and new vehicles. If subsequent technology packages can be applied to 

the vehicle, the user must consider whether in reality the new technology would likely be 

applied to those vehicles which received the previous technology or those which did not, 

or a combination of the two. The effectiveness of adding the subsequent technology may 

depend on which vehicles are receiving it. 
Results of Proposed and Alternative Standards 

4-9 

 In OMEGA, the costs and effectiveness of technologies are assumed to be 

the same for all vehicle models that belong to the sale vehicle type category. There may 

be cases when a vehicle model in the baseline may already contain some CO2-reducing 

technology; OMEGA considers this when determining whether a technology can or 

cannot be applied to it. In the inputs to the model, the user can limit the volume of a 

specific vehicle model’s sales which can receive a technology package by indicating the 

fraction of its baseline that already contains some effectiveness and cost of each specific 

technology package. In addition, as described above, the volume of a given vehicle 

type’s sales which can receive a specific technology package can also be limited in an 

input file with a market penetration “cap”, if desired. The effectiveness and application 

limits of each technology package can vary over time, if desired. 

 OMEGA adds technology effectiveness according to the following 

equation in which the subscripts t and t-1 represent the times before and after technology 

addition, respectively. The numerator the effectiveness of the current technology 

package and the denominator serves to “back out” any effectiveness that is present in the 

baseline. CAP refers to the market penetration cap, AIE is the “average incremental 

effectiveness” of the technology package on a vehicle type, and TEB is the “technology 

effectiveness basis”, which denotes the fraction of the technology present in the baseline. 

 

AIE TEB

CO AIECAP CO t

t  

  

1

12 2 1

 OMEGA then adds technology cost according to the equations below, 

where CEB refers to the “cost effectiveness basis”, or in other words, the technology cost 

that is present in the baseline. 

IncrementalCost  TechCost (*  CEBCAP )

MFR

MFR TotalFleetSales

TechCost ModelSales AvgVehicleCost 



 



  *

 EPA’s OMEGA model calculates the new CO2 and average vehicle cost 

after each technology package has been added. To simplify the model’s algorithm, EPA 

has chosen to input the package costs and effectiveness values on a step-wise basis. This 

is not the same “incremental” approach implemented in the Volpe model because each 

step in OMEGA has incorporated several technologies. However, for simplification in 
Draft Regulatory Impact Analysis 

4-10 

the core model calculations, the user must enter into the technology input file the 

technology costs which are incremental to the technology package immediately preceding 

it. In the case of the first technology package, this is simply the full technology package 

cost, since it is going on a baseline vehicle and since any technology in the baseline is 

considered in the equations, as described in the equations above. 

4.3 Modeling Process 

In order to determine the technology costs associated with this proposed rule, 

EPA performed two separate modeling exercises. The first was to determine the costs 

associated with meeting any existing regulation of CO2 or MPG. The latest regulation 

that has been promulgated is NHTSA’s CAFE program for MY 2011, directed under the 

Energy Independence and Security Act (EISA). EPA considers the MY 2011 CAFE 

regulations to constitute the “reference case” for calculating the costs and benefits of this 

GHG proposal. In other words, absent any further rulemaking, this is the vehicle fleet 

EPA would expect to see through 2016; the “status quo”. In order to calculate the costs 

and benefits of this proposed rule alone, EPA seeks to subtract out any costs associated 

with meeting any existing standards related to GHG emissions. EPA ran OMEGA a 

second time to calculate the cost of meeting the EPA’s proposed standards in 2016, and 

then subtracted the results of the reference case model run to determine the costs of this 

proposed GHG program. 

Conceptually, OMEGA begins by determining the specific CO2 emission 

standard applicable for each manufacturer and its vehicle class (i.e., car or truck). Since 

the proposed rule allows for averaging across a manufacturer’s cars and trucks, the model 

determines the CO2 emission standard applicable to each manufacturer’s car and truck 

sales from the two sets of coefficients describing the piecewise linear standard functions 

for cars and trucks in the inputs, and creates a combined car-truck standard. This 

combined standard considers the difference in lifetime VMT of cars and trucks, as 

indicated in the proposed regulations which would govern credit trading between these 

two vehicle classes. For both the 2011 CAFE and 2016 CO2 standards, these standards 

are a function of each manufacturer’s sales of cars and truck and their footprint values. 

When evaluating the 2011 MY CAFE standards, the car-truck trading was limited to 1.2 

mpg. When evaluating the proposed CO2 standards, the OMEGA model was run only 

for MY 2016. OMEGA is designed to evaluate technology addition over a complete 

redesign cycle and 2016 represents the final year of a redesign cycle starting with the first 

year of the proposed CO2 standards, 2012. Estimates of the technology and cost for the 

interim model years are developed from the model projections made for 2016. This 

process is discussed in Chapter 6 of EPA’s DRIA to this proposed rule. When evaluating 

the 2016 standards using OMEGA, the proposed CO2 standard which manufacturers 

would otherwise have to meet to account for the anticipated level of A/C credits 

generated was adjusted. On an industry wide basis, the projection shows that 

manufacturers would generate 11 g/mi of A/C credit in 2016. Thus, the 2016 CO2 target 

for the fleet evaluated using OMEGA was 261 g/mi instead of 250 g/mi. 
Results of Proposed and Alternative Standards 

4-11 

The cost of the improved A/C systems required to generate the 11 g/mi credit was 

estimated separately. This is consistent with the proposed A/C credit procedures, which 

would grant manufacturers A/C credits based on their total use of improved A/C systems, 

and not on the increased use of such systems relative to some base model year fleet. 

Some manufacturers may already be using improved A/C technology. However, this 

represents a small fraction of current vehicle sales. To the degree that such systems are 

already being used, EPA is over-estimating both the cost and benefit of the addition of 

improved A/C technology relative to the true reference fleet to a small degree. 

The model then works with one manufacturer at a time to add technologies until 

that manufacturer meets its applicable standard. The OMEGA model can utilize several 

approaches to determining the order in which vehicles receive technologies. For this 

analysis, EPA used a “manufacturer-based net cost-effectiveness factor” to rank the 

technology packages in the order in which a manufacturer would likely apply them. 

Conceptually, this approach estimates the cost of adding the technology from the 

manufacturer’s perspective and divides it by the mass of CO2 the technology will reduce. 

One component of the cost of adding a technology is its production cost, as discussed 

above. However, it is expected that new vehicle purchaser’s value improved fuel 

economy since it reduces the cost of operating the vehicle. Typical vehicle purchasers 

are assumed to value the fuel savings accrued over the period of time which they will 

own the vehicle, and is estimated to be roughly five years. It is also assumed that 

consumers discount these savings at the same rate as that used in the rest of the analysis 

(3 or 7 percent). Any residual value of the additional technology which might remain 

when the vehicle is sold is not considered. The CO2 emission reduction is the change in 

CO2 emissions multiplied by the percentage of vehicles surviving after each year of use 

multiplied by the annual miles travelled by age, again discounted to the year of vehicle 

purchase. 

Given this definition, the higher priority technologies are those with the lowest 

manufacturer-based net cost-effectiveness value (relatively low technology cost or high 

fuel savings leads to lower values). Because the order of technology application is set for 

each vehicle, the model uses the manufacturer-based net cost-effectiveness primarily to 

decide which vehicle receives the next technology addition. Initially, technology 

package #1 is the only one available to any particular vehicle. However, as soon as a 

vehicle receives technology package #1, the model considers the manufacturer-based net 

cost-effectiveness of technology package #2 for that vehicle and so on. In general terms, 

the equation describing the calculation of manufacturer-based cost effectiveness is as 

follows: 
Draft Regulatory Impact Analysis 

4-12 

 

      







 

 

 35

1

1

1 2

)1(

1

i

i

i

PP

i

i i

Gap

dCO VMT

Gap

TechCost VMTdFS

ManufCostEff

Where 

ManufCostEff = Manufacturer-Based Cost Effectiveness (in dollars per kilogram 

CO2), 

TechCost = Marked up cost of the technology (dollars), 

PP = Payback period, or the number of years of vehicle use over which consumers 

value fuel savings when evaluating the value of a new vehicle at time of purchase, 

dFSi = Difference in fuel consumption due to the addition of technology times 

fuel price in year i, 

dCO2 = Difference in CO2 emissions due to the addition of technology 

VMTi = product of annual VMT for a vehicle of age i and the percentage of 

vehicles of age i still on the road, 

1- Gap = Ratio of onroad fuel economy to two-cycle (FTP/HFET) fuel economy 

When calculating the fuel savings, the full retail price of fuel, including taxes is 

used. While taxes are not generally included when calculating the cost or benefits of a 

regulation, the net cost component of the manufacturer-based net cost-effectiveness 

equation is not a measure of the social cost of this proposal, but a measure of the private 

cost, (i.e., a measure of the vehicle purchaser’s willingness to pay more for a vehicle with 

higher fuel efficiency). Since vehicle operators pay the full price of fuel, including 

taxes, they value fuel costs or savings at this level, and the manufacturers will consider 

this when choosing among the technology options. 

This definition of manufacturer-based net cost-effectiveness ignores any change 

in the residual value of the vehicle due to the additional technology when the vehicle is 

five years old. It is reasonable to estimate that the added technology to improve CO2

level and fuel economy would retain this same percentage of value when the vehicle is 

five years old. However, it is less clear whether first purchasers, and thus, manufacturers 

would consider this residual value when ranking technologies and making vehicle 

purchases, respectively. For this proposal, this factor was not included in the 

determination of manufacturer-based net cost-effectiveness in the analyses performed in 
Results of Proposed and Alternative Standards 

4-13 

support of this proposed rule. Comments are requested on the benefit of including an 

increase in the vehicle’s residual value after five years in the calculation of effective cost. 

The values of manufacturer-based net cost-effectiveness for specific technologies 

will vary from vehicle to vehicle, often substantially. This occurs for three reasons. 

First, both the cost and fuel-saving component cost, ownership fuel-savings, and lifetime 

CO2 effectiveness of a specific technology all vary by the type of vehicle or engine to 

which it is being applied (e.g., small car versus large truck, or 4-cylinder versus 8-

cylinder engine). Second, the effectiveness of a specific technology often depends on the 

presence of other technologies already being used on the vehicle (i.e., the dis-synergies. 

Third, the absolute fuel savings and CO2 reduction of a percentage an incremental 

reduction in fuel consumption depends on the CO2 level of the vehicle prior to adding the 

technology. EPA requests comment on the use of manufacturer-based net costeffectiveness to rank CO2 emission reduction technologies in the context of evaluating 

alternative fleet average standards for this rule. EPA believes this manufacturer-based 

net cost-effectiveness metric is appropriate for ranking technology in this proposed 

program because it considers effectiveness values that may vary widely among 

technology packages when determining the order of technology addition. Comments are 

requested on this option and on any others thought to be appropriate. 

4.4 Modeling of CAA Compliance Flexibilities 

EPA’s proposed rule incorporates several compliance flexibilities. Three of these 

flexibilities, the credit for air conditioning system improvements, car-truck credit trading, 

and FFV credits, are expected to be used extensively by manufacturers and have been 

factored into our estimates of the cost of the proposed CO2 standards. OMEGA was 

designed to be able to address the first two types of flexibilities directly through the 

appropriate specification of model inputs and scenario definition. However, for several 

reasons, the expected impact of A/C credits was handled outside of OMEGA. The 

impact of car-truck credit trading was accomplished in a slightly more complex fashion 

than will be the case with future versions of the model. OMEGA was not originally 

designed to include FFV credits in terms of miles per gallon. The methods used to 

account for these three flexibilities are described below. 

OMEGA is capable of including both the impact of air conditioning use on CO2 

emissions from the tailpipe (indirect A/C emissions) and refrigerant emissions (direct 

A/C emissions). The current approach to specifying refrigerant emissions in the Market 

file and the effectiveness of refrigerant emission control in the Technology file allows for 

the straightforward accounting of EPA’s current approach to estimating both of these 

factors. As described in Chapter 2 above, EPA currently estimates the same base level of 

direct A/C emissions from cars and a distinct level of emissions from trucks. These 

levels can be input directly into Column AD of the Market file. The reduction in direct 

A/C emissions associated with improved A/C systems can be input into Column U of the 

Technology file. 
Draft Regulatory Impact Analysis 

4-14 

Accounting for indirect A/C emissions, consistent with our approach to estimating 

these emissions in Chapter 2, however, is more difficult. In Chapter 2, we estimate a 

single level of 14 g/mi CO2 from A/C usage and a potential reduction of 40% for a high 

efficiency A/C design (maximum A/C credit of 5.7 g/mi CO2). OMEGA currently 

combines all sources of CO2 tailpipe emissions (i.e., those measured over the 2-cycle 

compliance test and those from A/C usage). Adding 14 g/mi CO2 from A/C usage to the 

base emission level of all vehicles could be easily accomplished. However, specifying a 

consistent 40% reduction of this incremental emission level would not be. The CO2 

effectiveness of technologies included in the Technology file applies to all sources of 

CO2 emissions. Since the base 2-cycle CO2 emission level of vehicles varies, the 

additional 14 g/mi of indirect A/C emissions would represent a different percentage of 

total CO2 emissions of each vehicle. A single effectiveness value for the benefit of high 

efficiency A/C systems would therefore produce a slightly different CO2 emission 

reduction for each vehicle. 

In addition, OMEGA is currently designed to include both indirect and direct A/C 

emissions in the accounting of emissions towards compliance with the specified 

standards. This means that the 14 g/mi of indirect A/C emissions and 17-21 g/mi of 

direct A/C emissions are included in the base level of vehicles’ emissions. Their 

remaining levels after the application of technology are considered when determining 

whether a manufacturer is in compliance with the specified standards. However, this is 

not consistent with the design of the proposed A/C credit system. Neither direct nor 

indirect A/C emissions are included in the compliance determination towards the 

proposed CO2 emission standards. Compliance is determined based on CO2 emissions 

measured over the 2-cycle test procedure which does not include these A/C emissions. 

Then, reductions in A/C emissions are essentially subtracted from the measured 2-cycle 

CO2 emissions. 

With the current OMEGA model design, it was more straightforward to determine 

the total A/C credit applicable to each manufacturer in 2016 and adjust their proposed 

CO2 emission standards accordingly. Thus, the effective 2016 proposed car and truck 

standards were increased by 10.2 g/mi and 11.5 g/mi, respectively. OMEGA was then 

run to determine the level of non-A/C technology needed to meet the proposed standards 

after accounting for A/C credits. After modeling, EPA then added a uniform AC cost of 

$60 per vehicle to each manufacturer’s per vehicle technology cost. 

With respect to car-truck trading, OMEGA was originally designed to allow the 

trading of car-truck credits on a vehicle-g/mi CO2 basis. For example, if a manufacturer 

over-complies with its applicable CO2 standard for cars by 3 g/mi and it sells 1,000,000 

cars, it generates 3,000,000 vehicle-g/mi CO2 worth of credits. If these credits are used 

to compensate for under-compliance towards the truck CO2 standard and truck sales are 

500,000, the manufacturer’s truck CO2 emission level could be as much as 6 g/mi CO2 

above the standard. This is the credit trading approach used in EPA’s Tier 2 light-duty 

vehicle emission control program. 

As described in section III.B.4 of the Preamble to this proposed rule, EPA is 

proposing to trade car and truck credits on a lifetime CO2 emission basis. In the above 
Results of Proposed and Alternative Standards 

4-15 

example, cars are assumed to have a lifetime VMT of 152,000 miles. Therefore, the 

value of the 3 g/mi over-compliance is multiplied by 1,000,000 vehicles and 190,971 

miles and converted to metric tons, or 573,000 metric tons of CO2. If these credits are 

used to compensate for under-compliance towards the truck CO2 standard and truck sales 

are again 500,000, the manufacturer’s truck CO2 emission level could only be as much as 

5.2 g/mi CO2 above the standard, as the lifetime VMT of trucks is 221,199 miles. 

In order to simulate trading on a lifetime emission basis, we ran the OMEGA 

model with a single vehicle fleet (i.e., as if cars and trucks were being regulated 

identically). We adjusted the base CO2 emissions of trucks (in g/mi) to account for their 

higher lifetime VMT by multiplying them by 1.158 (the ratio of 221,199 to 190,971). 

We also adjusted the proposed CO2 emission standard applicable to each manufacturer in 

2016 to account for these higher truck emissions. Because each manufacturer has a 

different car-truck sales split, the degree to which their standards were increased varied. 

Thus, each manufacturer’s standard was specified as a universal or flat standard in the 

Scenario file (each manufacturer’s compliance was evaluated separately). This universal 

standard was essentially determined by applying the proposed 2016 car standard to each 

manufacturer’s cars and 1.158 times the proposed 2016 truck standard to each 

manufacturer’s trucks. The OMEGA input and output files using the latest version of the 

model, including the adjusted truck base CO2 levels and adjusted standards can be found 

under “EPA OMEGA Model” in the docket to this rule. 

Under the proposal, FFV credits are only available through model year 2015. 

Since we use the OMEGA model directly to evaluate technical feasibility and costs only 

for the 2016 model year, FFV credits are not a factor. (FFV credits use in earlier years is 

accounted for in projecting the cost of technology for 2012-2015 below.) However, as 

discussed above, some manufacturers’ 2008 baseline fleets (adjusted for projected sales 

in 2011) do not meet the 2011 CAFE standards which comprise the reference case for 

this analysis. FFV credits are available under this program and expected be used at the 

maximum allowable level by Chrysler, Ford and General Motors for both their cars and 

trucks and by Nissan for their trucks. Under the current CAFE program, FFV credits are 

limited to 1.2 mpg in 2011. Car-truck trading is also allowed under this program, up to 

1.0 mpg in 2011. However, our reference case is a 2016 vehicle fleet complying with the 

2011 CAFE standards. In 2016, the limit on FFV credits is reduced to 0.8 mpg and cartruck trading is increased to 1.5 mpg. We use these latter levels here. 

Because fuel economy is the inverse of fuel consumption, a specified change in 

fuel economy (e.g., either the limit on FFV credits or car-truck trading) represents a 

varying change in fuel consumption (and CO2 emissions) depending on the initial level 

of fuel economy. For example, for a manufacturer whose truck standard is 22.5 mpg, its 

trucks could be as low as 21 mpg if the manufacturer generated sufficient credits from its 

car fleet. These two fuel economy levels represent CO2 emission levels of 395 and 423 

g/mi, respectively, assuming all the vehicles are fueled with gasoline, a difference of 28 

g/mi CO2. If the manufacturer’s truck standard is 24 mpg, its trucks could be as low as 

23 mpg if the manufacturer generated sufficient credits from its car fleet. These two fuel 

economy levels represent CO2 emission levels of 363 and 386 g/mi, respectively, a 

difference of 23 g/mi CO2. In both cases, the difference in terms of mpg is 1.5. 
Draft Regulatory Impact Analysis 

4-16 

However, the difference in terms of CO2 emissions decreases as the base fuel economy 

increases. 

As mentioned above, the OMEGA model is not designed to incorporate a credit 

which is specified in terms of mpg. Since the effect in terms of CO2 emissions changes 

with the level of fuel economy standard and the footprint-based 2011 CAFE standards 

impose a different effective fuel economy standard on each manufacturer, these credits 

cannot be simulated in an OMEGA model run which represents the CO2 standard as a 

footprint-based standard. Thus, as was the case with the proposed 2016 standards, we 

determined the effective flat standard applicable to each manufacturer’s sales in 2011 

after accounting for expected use of FFV credits. The 2011 CAFE standards for cars and 

trucks were converted to CO2 emissions assuming that all vehicles were fueled with 

gasoline (i.e., 8887/mpg). Truck emissions were again increased by a factor of 1.158 and 

the car and truck standards for each manufacturer were sales weighted after again 

increasing the truck standard by this same factor. An exception was made for those 

manufacturers which traditionally pay CAFEE fines in lieu of compliance. For these 

manufacturers, we substituted the achieved fuel economy levels from NHTSA’s Volpe 

Model evaluations of the 2011 CAFEE standards for these manufacturers’ CAFEE 

standards. These manufacturers were BMW, Daimler, Porsche, Tata and Volkswagen. 

Also, several manufacturers were not run through the model, as their 2008 vehicles 

already complied with both 2011 car and truck CAFE standards: Honda, Kia, Mazda, and 

Toyota. 

This approach allows unlimited trading of car-truck credits to occur. This is 

consistent with the proposal for 2016, but not 2011. In order to determine whether the 

1.5 mpg car-truck trading limit had been exceeded, EPA converted the final car and truck 

CO2 emissions levels for each manufacturer to their fuel economy equivalents and 

compared these values to the applicable 2011 CAFE standards. If the fuel economy of 

the vehicle class which under-complied with its standard exceeded 1.5 mpg, the shortfall 

was reduced to 1.5 mpg and the fuel economy of the over-complying class decreased. 

The OMEGA model was then run for cars and trucks separately to determine the overall 

cost of these trading limited manufacturers. Only two manufacturers were found to 

exceed the trading limit in the unlimited trading runs, Daimler and Hyundai. The impact 

of limiting trading on projected technology costs in 2011 was very small, $8 and $3 per 

vehicle, respectively. Hyundai’s 2008 vehicles complied with the 2011 CAFEE 

standards with unlimited trading (i.e., zero compliance cost). However, limited trading 

required Hyundai to apply technology to their trucks. The OMEGA input and output 

files using the latest version of the model, including the adjusted truck base CO2 levels 

and adjusted standards can be found under “EPA OMEGA Model” in the docket to this 

rule. 

4.5 Per Vehicle Costs 2012-2016 

As described above, the per-vehicle technology costs for this program alone must 

account for any cost that incurred by compliance with existing vehicle programs. EPA 
Results of Proposed and Alternative Standards 

4-17 

first used OMEGA to calculate costs reflected in the existing CAFE program. OMEGA 

estimates that, on average, manufacturers will need to spend $78 per vehicle to meet the 

current MY 2011 CAFE standards. A Reference case costs are provided in Table 4-5 

below. 

Table 4-5 Incremental Technology Cost of the Reference Case 

 Cars Trucks Combined

BMW $ 319 $ 479 $ 361 

Chrysler $ 7 $ 125 $ 59 

Daimler $ 431 $ 632 $ 495 

Ford $ 28 $ 211 $ 109 

General Motors $ 28 $ 136 $ 73 

Honda $ 0 0 $ 0 

Hyundai $ 0 $ 76 $ 14 

Kia $ 0 $ 48 $ 8 

Mazda $ 0 $ 0 $ 0 

Mitsubishi $ 96 $ 322 $ 123 

Nissan $ 0 $ 19 $ 6 

Porsche $ 535 $ 1,074 $ 706 

Subaru $ 64 $ 100 $ 77 

Suzuki $ 99 $ 231 $ 133 

Tata $ 691 $ 1,574 $ 1,161 

Toyota $ 0 $ 0 $ 0 

Volkswagen $ 269 $ 758 $ 354 

Overall $ 47 $ 141 $ 78 

EPA then used OMEGA to calculate the costs of meeting the proposed 2016 

standards, which are displayed in Table 4-6 below, and two alternative scenarios for 

sensitivity. In Table 4-13 and Table 4-14, EPA presents the per-vehicle cost for these 

scenarios, respectively. EPA has accounted for the cost to meet the standards in the 

reference case. In other words, the following tables contain results of the OMEGA 

control case runs after the reference case values have been subtracted. 

 

 A It should be noted that the latest version of OMEGA projects slightly different costs than those shown 

here. This is usually due to an error when the model eliminates over-compliance which occurs with the last 

step of technology addition. The costs presented here reflect the correction of this error. The latest version 

of the model also reflects several improvements to the model’s algorithms when selecting between car and 

truck control. These revisions generally only change the projected cost by a dollar or two per vehicle and 

do not affect the overall conclusions of this analysis. 
Draft Regulatory Impact Analysis 

4-18 

Table 4-6 Incremental Technology Cost of the Proposed 2016 CO2 Standards 

Cars Trucks All

BMW $1,701 $1,665 $1,691 

Chrysler $1,331 $1,505 $1,408 

Daimler $1,631 $1,357 $1,543 

Ford $1,435 $1,485 $1,457 

General Motors $969 $1,782 $1,311 

Honda $606 $695 $633 

Hyundai $739 $1,680 $907 

Kia $741 $1,177 $812 

Mazda $946 $1,030 $958 

Mitsubishi $1,067 $1,263 $1,090 

Nissan $1,013 $1,194 $1,064 

Porsche $1,549 $666 $1,268 

Subaru $903 $1,329 $1,057 

Suzuki $1,093 $1,263 $1,137 

Tata $1,270 $674 $952 

Toyota $600 $436 $546 

Volkswagen $1,626 $949 $1,509 

Overall $968 $1,214 $1,051 

EPA estimates that the additional technology required for manufacturers to meet 

the GHG standards in this proposed rule will cost on average $1051/vehicle. 

The majority of manufacturers representing the vast majority of sales in 2016 are 

projected to comply with the proposed 2016 standards with the addition of technology 

under the penetration limits described above. However, several smaller volume 

manufacturers (at least with respect to U.S. sales) are projected to fall short of 

compliance. The CO2 standards applicable to each manufacturer based on its distribution 

of sales and vehicle footprints are shown in Table 4-7 along with the projected achieved 

level of CO2 emissions from the OMEGA model. 
Results of Proposed and Alternative Standards 

4-19 

Table 4-7 CO2 Standards and Projected Achieved Levels in 2016 

 Car Truck 

Manufacturer Standard Achieved CO2 Standard Achieved CO2 

BMW * 237.1 245.8 295.2 339.7 

Chrysler 241.7 220.1 312.2 334.1 

Daimler * 244.1 246 305.6 363 

Ford 238.5 225.1 326 353.6 

General Motors 238.5 221.2 333.9 349.4 

Honda 231.6 186.3 292.7 302.8 

Hyundai 231.8 196.8 290.4 308 

Kia 233.7 191.6 300.7 310.5 

Mazda 230.5 205.6 283.4 285.4 

Mitsubishi 227.5 212.4 281.7 319.7 

Nissan 235.3 212.5 315.7 351.5 

Porsche * 214.8 247.8 298.7 398.5 

Subaru 224.7 208.3 279.1 270.7 

Suzuki 216.8 197.4 283.7 312.1 

Tata * 258.6 270.6 287.1 397.4 

Toyota 230 188.1 303.2 307.3 

Volkswagen * 227.2 240.6 304.8 394.9 

Overall 234 208.8 314 334.6 

4.6 Technology Penetration 

 The major technologies chosen by OMEGA are described in the Table 4-8 

through Table 4-11 below for the reference case and control case cars and trucks. The 

values in the table containing the control case technology are for that alone – EPA has 

subtracted out the impact of the reference case. 
Regulatory Impact Analysis 

4-20 

Table 4-8 2016 Technology Penetration in the Reference Case-Cars 

Cars VVT VVTL GDI 

GDI 

Deac 

GDI 

Turbo Diesel

6 Spd 

Auto 

Wet 

DCT 

Dry 

DCT 

42 SS IMA Power Split 2- Mode 

BMW 85.9% 11.9% 8.9% 9.0% 0.0% 0.0% 88.5% 9.0% 0.0% 9.0% 0.0% 0.2% 0.0% Chrysler 48.0% 0.0% 0.0% 0.0% 0.0% 0.0% 23.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Daimler 47.0% 0.0% 5.2% 15.2% 0.0% 1.6% 45.1% 31.9% 0.0% 15.2% 0.0% 0.0% 0.0% Ford 12.7% 0.0% 0.0% 0.0% 0.0% 0.0% 36.8% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% General Motors 54.9% 0.0% 5.6% 0.0% 0.0% 0.0% 13.2% 0.0% 0.0% 0.2% 0.0% 0.0% 0.1% Honda 0.0% 100.0% 0.0% 0.0% 0.0% 0.0% 5.9% 0.0% 0.0% 0.0% 3.0% 0.0% 0.0% Hyundai 29.9% 0.0% 0.0% 0.0% 0.0% 0.0% 0.1% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Kia 24.2% 0.0% 0.0% 0.0% 0.0% 0.0% 0.8% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Mazda 96.0% 3.3% 13.4% 0.0% 0.0% 0.0% 36.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Mitsubishi 77.8% 0.0% 0.0% 0.0% 0.0% 0.0% 77.4% 0.0% 0.0% 0.0% 0.0% 0.1% 0.0% Nissan 99.8% 0.0% 5.1% 0.0% 0.0% 0.0% 26.6% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Porsche 31.1% 0.0% 0.0% 14.8% 16.3% 0.0% 0.0% 31.1% 0.0% 14.8% 0.0% 0.0% 0.0% Subaru 48.7% 3.3% 0.0% 0.0% 0.0% 0.0% 26.9% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Suzuki 100.0% 0.0% 0.0% 0.0% 0.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Tata 64.4% 0.0% 31.1% 33.4% 0.0% 0.0% 31.1% 33.4% 0.0% 33.4% 0.0% 0.0% 0.0% Toyota 99.7% 0.0% 7.1% 0.0% 0.0% 0.0% 35.7% 0.0% 0.0% 0.0% 0.0% 15.8% 0.0% 6Volkswagen 16.8% 0.7% 41.0% 4.7% 0.0% 0.0% 73.6% 17.9% 0.0% 4.7% 0.0% 0.0% 0.0% Overall 53.0% 15.0% 5.6% 1.0% 0.1% 0.0% 27.8% 2.0% 0.0% 1.0% 0.4% 3.1% 0.0% 1
Results of Proposed and Alternative Stan

4-21 

Table 4-9 2016 Technology Penetration in the Reference Case-Trucks 

Trucks VVT VVTL GDI 

GDI 

Deac 

GDI 

Turbo Diesel

6 Spd 

Auto 

Wet 

DCT 

Dry 

DCT 

42 SS IMA Power Split 2- Mode 

BMW 97.0% 0.0% 3.0% 16.9% 0.0% 0.0% 80.1% 16.9% 0.0% 16.9% 0.0% 0.0% 0.0% Chrysler 4.8% 0.0% 0.1% 0.0% 0.0% 0.1% 34.1% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Daimler 92.9% 0.0% 40.3% 0.0% 44.7% 16.1% 47.3% 44.7% 0.0% 44.7% 0.0% 0.0% 0.0% Ford 37.7% 0.0% 1.3% 0.0% 0.0% 0.0% 17.2% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% GeneralMotors 24.6% 0.0% 0.0% 0.0% 0.0% 0.0% 14.3% 0.0% 0.0% 0.0% 0.0% 0.0% 0.1% Honda 0.0% 100.0% 4.2% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Hyundai 28.6% 0.0% 0.0% 0.0% 0.0% 0.0% 27.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Kia 98.8% 0.0% 0.0% 0.0% 0.0% 0.0% 1.2% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Mazda 49.9% 0.0% 2.5% 0.0% 0.0% 0.0% 43.5% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Mitsubishi 100.0% 0.0% 0.0% 18.4% 0.0% 0.0% 64.9% 18.4% 0.0% 18.4% 0.0% 0.0% 0.0% Nissan 100.0% 49.5% 49.5% 0.0% 0.0% 0.0% 50.1% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Porsche 91.6% 0.0% 0.0% 47.0% 38.0% 0.0% 0.0% 85.0% 0.0% 85.0% 0.0% 0.0% 0.0% Subaru 32.6% 0.0% 0.0% 0.0% 0.0% 0.0% 32.6% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Suzuki 100.0% 0.0% 17.8% 0.0% 0.0% 0.0% 100.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% Tata 85.0% 0.0% 0.0% 85.0% 0.0% 0.0% 0.0% 85.0% 0.0% 85.0% 0.0% 0.0% 0.0% Toyota 85.5% 0.0% 8.1% 0.0% 0.0% 0.0% 20.0% 0.0% 0.0% 0.0% 0.0% 6.6% 0.0% 6Volkswagen 99.3% 0.0% 100.0% 17.3% 67.7% 0.7% 0.0% 85.0% 0.0% 85.0% 0.0% 0.0% 0.0% Overall 48.6% 16.0% 9.0% 1.6% 2.2% 0.3% 20.5% 3.8% 0.0% 3.8% 0.0% 1.3% 0.0% 1
Regulatory Impact Analysis 

4-22 

Table 4-10 2016 Technology Penetration in the Control Case-Cars 

Cars 

VVT VVTL GDI GDI Deac GDI Turbo Diesel 6 Spd Auto Wet DCT Dry DCT 42 S- S IMA Power Split 2- Mode EP

BMW 97.8% 2.0% 4.9% 37.2% 44.1% 0.0% 14.8% 65.5% 5.7% 71.0% 0.0% 3.9% 10.3% 100.0Chrysler 46.2% 44.3% 59.0% 19.1% 0.8% 0.0% 24.2% 18.0% 44.3% 62.2% 0.0% 0.0% 0.0% 100.Daimler 89.2% 0.0% 3.4% 42.0% 39.9% 1.6% 9.4% 60.8% 14.2% 72.5% 0.0% 3.2% 9.3% 100.0Ford 51.9% 27.0% 27.0% 37.7% 12.2% 0.0% 11.1% 46.0% 27.0% 73.0% 0.0% 0.0% 0.0% 100.0General Motors 43.5% 37.2% 40.6% 11.0% 2.9% 0.0% 5.0% 13.4% 37.2% 50.6% 0.0% 0.0% 0.1% 100.0Honda 0.0% 100.0% 24.0% 0.0% 0.0% 0.0% 5.8% 0.0% 24.0% 24.0% 3.0% 0.0% 0.0% 100.Hyundai 16.9% 31.3% 34.1% 1.8% 0.8% 0.0% 2.8% 2.6% 31.3% 33.9% 0.0% 0.0% 0.0% 100.Kia 4.5% 35.6% 35.6% 0.0% 0.0% 0.0% 0.0% 0.0% 35.6% 35.6% 0.0% 0.0% 0.0% 100.Mazda 64.3% 28.4% 61.3% 1.5% 11.6% 0.0% 34.5% 13.1% 28.2% 41.3% 0.0% 0.0% 0.0% 100.0Mitsubishi 21.8% 65.5% 74.1% 0.0% 0.0% 0.0% 22.6% 0.0% 65.5% 65.5% 0.0% 0.0% 0.0% 100.0Nissan 63.8% 36.2% 36.2% 22.6% 3.2% 0.0% 33.3% 25.8% 36.2% 60.5% 0.0% 1.0% 0.0% 100.Porsche 100.0% 0.0% 2.6% 27.2% 57.8% 0.0% 7.8% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0Subaru 14.6% 42.5% 42.4% 3.5% 6.6% 0.0% 0.4% 10.1% 42.4% 52.6% 0.0% 0.0% 0.0% 100.Suzuki 0.0% 76.2% 76.2% 0.0% 0.0% 0.0% 0.0% 0.0% 76.2% 76.2% 0.0% 0.0% 0.0% 100.Tata 100.0% 0.0% 3.6% 81.4% 0.0% 0.0% 13.7% 70.0% 0.0% 70.0% 0.0% 3.6% 11.4% 100.Toyota 64.9% 34.8% 41.6% 2.3% 0.0% 0.0% 31.2% 26.5% 21.1% 23.4% 0.0% 15.8% 0.0% 100.Volkswagen 87.4% 0.1% 7.7% 25.2% 58.4% 0.0% 11.9% 72.0% 0.0% 70.0% 0.0% 1.4% 13.5% 100.0Overall 47.0% 40.3% 33.2% 13.8% 8.0% 0.0% 15.6% 24.3% 27.1% 46.4% 0.4% 3.4% 1.2% 100.
Results of Proposed and Alternative Stan

4-23 

Table 4-11 2016 Technology Penetration in the Control Case-Trucks 

Trucks 

VVT VVTL GDI GDI Deac GDI Turbo Diesel 6 Spd Auto Wet DCT Dry DCT 42 S- S IMA Power Split 2- Mode EPS 

BMW 99.5% 0.0% 0.5% 29.0% 56.0% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0Chrysler 81.6% 4.1% 41.1% 39.3% 4.6% 0.1% 52.5% 33.5% 4.1% 37.6% 0.0% 0.0% 0.0% 100.0Daimler 92.9% 0.0% 2.4% 47.8% 37.2% 16.1% 15.0% 70.1% 0.0% 70.1% 0.0% 0.0% 14.9% 100.0Ford 84.5% 6.1% 32.3% 39.6% 13.2% 0.0% 28.6% 53.2% 5.7% 58.6% 0.0% 0.0% 0.0% 100.0General Motors 83.1% 3.5% 24.3% 45.6% 13.0% 0.0% 23.0% 58.6% 3.5% 62.1% 0.0% 0.0% 0.1% 100.0Honda 30.7% 69.3% 24.4% 3.5% 7.9% 0.0% 19.3% 11.5% 4.5% 16.0% 0.0% 0.0% 0.0% 100.0Hyundai 89.3% 0.0% 0.0% 8.5% 76.5% 0.0% 4.0% 85.0% 0.0% 85.0% 0.0% 0.0% 0.0% 100.0Kia 77.3% 0.0% 42.7% 0.0% 33.0% 0.0% 42.7% 33.0% 0.0% 33.0% 0.0% 0.0% 0.0% 100.0Mazda 92.9% 7.0% 9.9% 5.8% 40.8% 0.0% 7.2% 46.6% 7.0% 53.6% 0.0% 0.0% 0.0% 100.0Mitsubishi 90.3% 0.0% 0.0% 18.4% 55.2% 0.0% 16.7% 73.6% 0.0% 73.6% 0.0% 0.0% 0.0% 100.0Nissan 98.6% 1.4% 11.8% 36.0% 8.4% 0.0% 34.1% 44.4% 1.4% 45.9% 0.0% 0.0% 0.0% 100.0Porsche 85.0% 15.0% 15.0% 53.7% 31.3% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0Subaru 34.4% 57.0% 51.5% 5.8% 27.7% 0.0% 0.0% 69.3% 15.7% 49.2% 0.0% 0.0% 0.0% 100.0Suzuki 85.0% 0.0% 35.7% 17.8% 31.6% 0.0% 35.7% 49.3% 0.0% 49.3% 0.0% 0.0% 0.0% 100.0Tata 100.0% 0.0% 4.1% 80.9% 0.0% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 4.1% 10.9% 100.0Toyota 93.6% 0.0% 27.4% 2.1% 0.0% 0.0% 28.2% 2.1% 0.0% 2.1% 0.0% 6.6% 0.0% 100.0Volkswagen 87.9% 11.9% 15.0% 29.2% 55.8% 0.7% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0Overall 80.7% 11.8% 24.5% 27.3% 14.0% 0.3% 25.0% 40.6% 3.1% 43.1% 0.0% 1.3% 1.1% 100.0
Regulatory Impact Analysis 

4-24 

As can be seen, the overall reduction in vehicle weight is projected to be 4%. This 

reduction varies across the two vehicle classes and vehicle base weight. For cars below 2950 

pounds curb weight, the reduction is 2.3% (62 pounds), while it was 4.4% (154 pounds) for cars 

above 2950 curb weight. For trucks below 3850 pounds curb weight, the reduction is 3.5% (119 

pounds), while it was 4.5% (215 pounds) for trucks above 3850 curb weight. Splitting trucks at a 

higher weight, for trucks below 5000 pounds curb weight, the reduction is 3.3% (140 pounds), 

while it was 6.7% (352 pounds) for trucks above 5000 curb weight. These results are tabulated 

below in Table 4-12. 

Table 4-12 Breakdown of Weight Reduction in Modeling Results 

 Weight 

Category 

% Weight 

Reduction 

Average 

Weight 

Reduction 

< 2950 lbs 2.3% 62 lbs Cars > 2950 lbs 4.4% 154 lbs 

Trucks with 3850 < 3850 lbs 3.5% 119 lbs 

lb break point > 3850 lbs 4.5% 215 lbs 

Trucks with 5000 < 5000 lbs 3.3% 140 lbs 

lb break point > 5000 lbs 6.7% 352 lbs 

4.7 Manufacturer-Specific Standards 

 As described in Section 3.2, in any attribute-based regulatory structure, manufacturers 

are bound to have different overall GHG targets, since they are based on the size and sales mix 

of each manufacturer. The fleet-wide averages calculated for the proposed 2016 model year are 

presented in Table 4-13. 
Results of Proposed and Alternative Standards 

4-25 

Table 4-13 2016 Projected Standards by Manufacturer 

 Standards 

 Cars Trucks Combined

BMW 226.9 283.7 241.8

Chrysler 231.5 300.7 262.1

Daimler 233.9 294.1 253.2

Ford 228.3 314.5 266.5

General Motors 228.3 322.4 267.9

Honda 221.4 281.2 239.2

Hyundai 221.6 278.9 231.8

Kia 223.5 289.2 234.2

Mazda 220.3 271.9 227.7

Mitsubishi 217.3 270.2 223.5

Nissan 225.1 304.2 247.5

Porsche 204.6 287.2 230.8

Subaru 214.5 267.6 233.7

Suzuki 206.6 272.2 223.4

Tata 248.4 275.6 262.8

Toyota 219.8 291.7 243.5

Volkswagen 217.0 293.3 230.3

Overall 223.8 302.5 250.2

These car and truck standards average out to an overall industry CO2 stringency of 250 

g/mi, consistent with President Obama’s announcement on May 19, 2009. 

4.8 Alternative Program Stringencies 

 EPA analyzed the technology cost of two alternative stringency scenarios: 4%/year and 

6%/year. With the reference case the same as that described above in Section 4.1, the costs of 

the two alternative control cases along with the technology penetrations and the manufacturerspecific standards are presented in Table 4-14 through Table 4-19, below. The manufacturers’s 

CO2 targets for these alternative standards are presented in Table 4-20 and Table 4-21. 
Regulatory Impact Analysis 

4-26 

Table 4-14 2016 Technology Cost in the 4% sensitivity case 

 Cars Trucks All 

BMW $ 1,701 $ 1,665 $ 1,691 

Chrysler $ 1,167 $ 1,505 $ 1,316 

Daimler $ 1,631 $ 1,357 $ 1,543 

Ford $ 1,339 $ 1,417 $ 1,373 

General Motors $ 850 $ 1,769 $ 1,237 

Honda $ 606 $ 460 $ 563 

Hyundai $ 685 $ 1,505 $ 832 

Kia $ 741 $ 738 $ 741 

Mazda $ 819 $ 1,030 $ 849 

Mitsubishi $ 1,004 $ 1,263 $ 1,034 

Nissan $ 910 $ 1,194 $ 991 

Porsche $ 1,549 $ 666 $ 1,268 

Subaru $ 903 $ 1,131 $ 985 

Suzuki $ 1,093 $ 1,026 $ 1,076 

Tata $ 1,270 $ 674 $ 952 

Toyota $ 479 $ 436 $ 465 

Volkswagen $ 1,626 $ 949 $ 1,509 

Overall $ 893 $ 1,154 $ 980 
Results of Proposed and Alternative Standards 

4-27 

Table 4-15 2016 Technology Cost in the 6% sensitivity case 

 Cars Trucks All 

BMW $ 1,701 $ 1,665 $ 1,691 

Chrysler $ 1,642 $ 2,211 $ 1,893 

Daimler $ 1,631 $ 1,357 $ 1,543 

Ford $ 2,175 $ 2,396 $ 2,273 

General Motors $ 1,718 $ 2,158 $ 1,903

Honda $ 777 $ 1,580 $ 1,016 

Hyundai $ 1,275 $ 1,680 $ 1,347 

Kia $ 1,104 $ 1,772 $ 1,213 

Mazda $ 1,321 $ 1,293 $ 1,317 

Mitsubishi $ 1,495 $ 2,065 $ 1,563 

Nissan $ 1,654 $ 2,274 $ 1,830 

Porsche $ 1,549 $ 666 $ 1,268 

Subaru $ 1,440 $ 1,615 $ 1,503

Suzuki $ 1,718 $ 2,219 $ 1,846 

Tata $ 1,270 $ 674 $ 952 

Toyota $ 755 $ 1,182 $ 895 

Volkswagen $ 1,626 $ 949 $ 1,509 

Overall $ 1,381 $ 1,866 $ 1,544 
Regulatory Impact Analysis 

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Table 4-16 2016 Technology Penetration in the 4% sensitivity case- Cars 

Cars 

VVT VVTL GDI GDI Deac GDI Turbo Diesel 6 Spd Auto Wet DCT Dry DCT 42 S- S IMA Power Split 2- Mode EP

BMW 97.8% 2.0% 4.9% 37.2% 44.1% 0.0% 14.8% 65.5% 5.7% 71.0% 0.0% 3.9% 10.3% 100Chrysler 33.3% 44.3% 51.7% 13.6% 0.8% 0.0% 16.9% 12.4% 44.3% 56.7% 0.0% 0.0% 0.0% 100Daimler 89.2% 0.0% 3.4% 42.0% 39.9% 1.6% 9.4% 60.8% 14.2% 72.5% 0.0% 3.2% 9.3% 100Ford 50.0% 27.0% 36.1% 26.8% 12.2% 0.0% 16.2% 39.0% 27.0% 66.1% 0.0% 0.0% 0.0% 100General Motors 56.1% 23.8% 40.3% 10.6% 2.9% 0.0% 17.6% 13.4% 23.8% 37.3% 0.0% 0.0% 0.1% 100Honda 0.0% 100.0% 24.0% 0.0% 0.0% 0.0% 5.8% 0.0% 24.0% 24.0% 3.0% 0.0% 0.0% 100Hyundai 17.4% 31.3% 31.3% 0.0% 0.8% 0.0% 0.0% 0.8% 31.3% 32.1% 0.0% 0.0% 0.0% 100Kia 4.5% 35.6% 35.6% 0.0% 0.0% 0.0% 0.0% 0.0% 35.6% 35.6% 0.0% 0.0% 0.0% 100Mazda 40.7% 28.4% 37.7% 1.5% 11.6% 0.0% 10.9% 13.1% 28.2% 41.3% 0.0% 0.0% 0.0% 100Mitsubishi 29.2% 58.2% 74.1% 0.0% 0.0% 0.0% 29.9% 0.0% 58.2% 58.2% 0.0% 0.0% 0.0% 100Nissan 63.8% 36.2% 42.3% 16.6% 0.0% 0.0% 41.9% 16.6% 36.2% 52.8% 0.0% 1.0% 0.0% 100Porsche 100.0% 0.0% 2.6% 27.2% 57.8% 0.0% 7.8% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100Subaru 14.6% 42.5% 42.4% 3.5% 6.6% 0.0% 0.4% 10.1% 42.4% 52.6% 0.0% 0.0% 0.0% 100Suzuki 0.0% 76.2% 76.2% 0.0% 0.0% 0.0% 0.0% 0.0% 76.2% 76.2% 0.0% 0.0% 0.0% 100Tata 100.0% 0.0% 3.6% 81.4% 0.0% 0.0% 13.7% 70.0% 0.0% 70.0% 0.0% 3.6% 11.4% 100Toyota 82.0% 17.7% 24.5% 2.3% 0.0% 0.0% 31.2% 43.6% 4.0% 6.3% 0.0% 15.8% 0.0% 100Volkswagen 87.4% 0.1% 7.7% 25.2% 58.4% 0.0% 11.9% 72.0% 0.0% 70.0% 0.0% 1.4% 13.5% 100Overall 51.3% 34.8% 30.7% 11.4% 7.7% 0.0% 18.3% 25.6% 21.6% 39.0% 0.4% 3.4% 1.2% 100
Results of Proposed and Alternative Stan

4-29 

Table 4-17 2016 Technology Penetration in the 4% sensitivity case- Trucks 

Trucks 

VVT VVTL GDI GDI Deac GDI Turbo Diesel 6 Spd Auto Wet DCT Dry DCT 42 S- S IMA Power Split 2-Mode E

BMW 99.5% 0.0% 0.5% 29.0% 56.0% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100Chrysler 81.6% 4.1% 41.1% 39.3% 4.6% 0.1% 52.5% 33.5% 4.1% 37.6% 0.0% 0.0% 0.0% 100Daimler 92.9% 0.0% 2.4% 47.8% 37.2% 16.1% 15.0% 70.1% 0.0% 70.1% 0.0% 0.0% 14.9% 100Ford 84.5% 2.8% 29.9% 38.7% 13.2% 0.0% 31.1% 51.9% 2.8% 54.7% 0.0% 0.0% 0.0% 100General Motors 82.0% 3.5% 23.1% 45.6% 13.0% 0.0% 21.8% 58.6% 3.5% 62.1% 0.0% 0.0% 0.1% 100Honda 10.3% 69.3% 11.9% 3.5% 0.0% 0.0% 6.8% 3.5% 4.5% 8.1% 0.0% 0.0% 0.0% 100Hyundai 84.0% 0.0% 7.8% 8.5% 63.5% 0.0% 11.8% 71.9% 0.0% 71.9% 0.0% 0.0% 0.0% 100Kia 34.6% 0.0% 7.7% 0.0% 25.3% 0.0% 7.7% 25.3% 0.0% 25.3% 0.0% 0.0% 0.0% 100Mazda 92.9% 7.0% 9.9% 5.8% 40.8% 0.0% 7.2% 46.6% 7.0% 53.6% 0.0% 0.0% 0.0% 100Mitsubishi 90.3% 0.0% 0.0% 18.4% 55.2% 0.0% 16.7% 73.6% 0.0% 73.6% 0.0% 0.0% 0.0% 100Nissan 98.6% 1.4% 11.8% 36.0% 8.4% 0.0% 34.1% 44.4% 1.4% 45.9% 0.0% 0.0% 0.0% 100Porsche 85.0% 15.0% 15.0% 53.7% 31.3% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100Subaru 61.5% 29.9% 51.5% 5.8% 27.7% 0.0% 27.1% 57.9% 0.0% 33.5% 0.0% 0.0% 0.0% 100Suzuki 85.0% 0.0% 59.5% 17.8% 7.7% 0.0% 59.5% 25.5% 0.0% 25.5% 0.0% 0.0% 0.0% 100Tata 100.0% 0.0% 4.1% 80.9% 0.0% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 4.1% 10.9% 100Toyota 93.6% 0.0% 27.4% 2.1% 0.0% 0.0% 28.2% 2.1% 0.0% 2.1% 0.0% 6.6% 0.0% 100Volkswagen 87.9% 11.9% 15.0% 29.2% 55.8% 0.7% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100Overall 77.6% 10.7% 22.1% 27.1% 12.6% 0.3% 24.0% 38.7% 2.2% 40.6% 0.0% 1.3% 1.1% 100
Regulatory Impact Analysis 

4-30 

Table 4-18 2016 Technology Penetration in the 6% Sensitivity Case-Cars 

Cars 

VVT VVTL GDI GDI Deac GDI Turbo Diesel 6 Spd Auto Wet DCT Dry DCT 42 S- S IMA Power Split 2- Mode EPS 

BMW 97.8% 2.0% 4.9% 37.2% 44.1% 0.0% 14.8% 65.5% 5.7% 71.0% 0.0% 3.9% 10.3% 100.0%Chrysler 43.7% 48.5% 48.5% 33.6% 2.9% 0.0% 3.7% 36.2% 48.5% 84.7% 0.0% 0.0% 0.0% 100.0%Daimler 89.2% 0.0% 3.4% 42.0% 39.9% 1.6% 9.4% 60.8% 14.2% 72.5% 0.0% 3.2% 9.3% 100.0%Ford 79.3% 7.6% 13.3% 35.8% 35.8% 0.0% 5.5% 41.1% 32.0% 73.1% 1.6% 5.5% 4.8% 100.0%General Motors 53.8% 39.4% 40.2% 42.7% 2.9% 0.0% 8.1% 39.5% 39.4% 78.9% 0.0% 0.0% 0.1% 100.0%Honda 5.7% 86.5% 41.1% 0.0% 0.0% 0.0% 11.0% 0.0% 35.4% 35.4% 3.0% 0.0% 0.0% 100.0%Hyundai 39.8% 35.2% 43.4% 9.3% 17.8% 0.0% 8.2% 27.1% 35.2% 62.3% 0.0% 0.0% 0.0% 100.0%Kia 35.2% 35.6% 56.8% 0.0% 13.2% 0.0% 21.3% 13.2% 35.6% 48.7% 0.0% 0.0% 0.0% 100.0%Mazda 32.5% 67.3% 68.5% 1.5% 11.6% 0.0% 2.7% 13.1% 67.2% 80.3% 0.0% 0.0% 0.0% 100.0%Mitsubishi 28.1% 64.2% 66.8% 4.3% 13.9% 0.0% 6.9% 7.1% 74.1% 81.2% 1.9% 1.2% 0.8% 100.0%Nissan 61.8% 38.2% 46.5% 19.3% 19.2% 0.0% 10.8% 21.7% 53.6% 75.3% 4.3% 5.7% 0.7% 100.0%Porsche 100.0% 0.0% 2.6% 27.2% 57.8% 0.0% 7.8% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0%Subaru 14.6% 75.0% 74.9% 3.5% 6.6% 0.0% 0.4% 17.6% 67.4% 77.6% 0.0% 0.0% 0.0% 100.0%Suzuki 85.0% 0.0% 1.5% 7.2% 76.2% 0.0% 0.0% 7.2% 76.2% 83.5% 0.0% 1.5% 0.0% 100.0%Tata 100.0% 0.0% 3.6% 81.4% 0.0% 0.0% 13.7% 70.0% 0.0% 70.0% 0.0% 3.6% 11.4% 100.0%Toyota 54.4% 45.3% 52.2% 2.3% 0.0% 0.0% 31.2% 2.3% 45.3% 47.6% 0.0% 15.8% 0.0% 100.0%Volkswagen 87.4% 0.1% 7.7% 25.2% 58.4% 0.0% 11.9% 72.0% 0.0% 70.0% 0.0% 1.4% 13.5% 100.0%Overall 52.8% 39.7% 37.9% 19.1% 14.8% 0.0% 13.4% 24.9% 38.1% 62.8% 1.1% 4.7% 2.0% 100.0%
Results of Proposed and Alternative Stan

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Table 4-19 2016 Technology Penetration in the 6% Sensitivity Case-Trucks 

Trucks 

VVT VVTL GDI GDI Deac GDI Turbo Diesel 6 Spd Auto Wet DCT Dry DCT 42 S- S IMA Power Split 2- Mode EPS 

BMW 99.5% 0.0% 0.5% 29.0% 56.0% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0%Chrysler 81.6% 4.1% 4.1% 70.1% 10.8% 0.1% 5.1% 80.9% 4.1% 85.0% 0.0% 0.0% 0.0% 100.0%Daimler 92.9% 0.0% 2.4% 47.8% 37.2% 16.1% 15.0% 70.1% 0.0% 70.1% 0.0% 0.0% 14.9% 100.0%Ford 90.7% 0.0% 2.2% 38.0% 45.0% 0.0% 2.6% 71.0% 5.0% 76.1% 0.0% 3.1% 5.8% 100.0%General Motors 87.0% 1.7% 1.7% 68.5% 14.8% 0.0% 2.1% 81.5% 3.5% 85.0% 0.0% 0.0% 0.1% 100.0%Honda 54.0% 46.0% 31.6% 3.5% 50.4% 0.0% 0.0% 54.0% 31.0% 85.0% 0.0% 0.0% 0.0% 100.0%Hyundai 89.3% 0.0% 0.0% 8.5% 76.5% 0.0% 4.0% 85.0% 0.0% 85.0% 0.0% 0.0% 0.0% 100.0%Kia 85.4% 1.1% 1.1% 0.0% 83.9% 0.0% 0.0% 83.9% 1.1% 85.0% 0.0% 0.0% 0.0% 100.0%Mazda 63.4% 36.5% 41.3% 5.8% 40.8% 0.0% 9.0% 76.2% 7.0% 53.6% 0.0% 0.0% 0.0% 100.0%Mitsubishi 90.3% 0.0% 3.2% 24.9% 56.9% 0.0% 5.3% 60.6% 9.4% 70.0% 0.0% 5.3% 9.7% 100.0%Nissan 100.0% 0.0% 0.8% 9.8% 74.4% 0.0% 3.7% 59.2% 17.7% 76.9% 0.0% 4.6% 3.6% 100.0%Porsche 85.0% 15.0% 15.0% 53.7% 31.3% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0%Subaru 34.4% 57.0% 51.5% 5.8% 27.7% 0.0% 0.0% 33.5% 51.5% 85.0% 0.0% 0.0% 0.0% 100.0%Suzuki 85.0% 0.0% 3.1% 26.5% 55.4% 0.0% 0.0% 70.0% 0.0% 70.0% 0.0% 3.1% 11.9% 100.0%Tata 100.0% 0.0% 4.1% 80.9% 0.0% 0.0% 15.0% 70.0% 0.0% 70.0% 0.0% 4.1% 10.9% 100.0%Toyota 82.0% 3.2% 15.0% 17.6% 34.2% 0.0% 13.6% 51.8% 3.2% 55.0% 0.0% 6.6% 0.0% 100.0%Volkswagen 87.9% 11.9% 15.0% 29.2% 55.8% 0.7% 15.0% 70.0% 0.0% 70.0% 0.0% 0.0% 15.0% 100.0%Overall 83.4% 8.1% 9.2% 33.8% 39.0% 0.3% 5.3% 67.0% 8.5% 75.2% 0.0% 2.3% 2.7% 100.0%
Regulatory Impact Analysis 

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Table 4-20 2016 Standards by Manufacturer in the 4% Sensitivity Case 

 Standards 

 Cars Trucks Combined 

BMW 230.3 288.3 245.5 

Chrysler 235.0 305.3 266.0 

Daimler 237.4 298.7 257.0 

Ford 231.7 319.0 270.4 

General Motors 231.8 327.0 271.8 

Honda 224.8 285.8 242.9 

Hyundai 225.0 283.5 235.4 

Kia 226.9 293.8 237.8 

Mazda 223.7 276.5 231.3 

Mitsubishi 220.7 274.7 227.1 

Nissan 228.5 308.7 251.3 

Porsche 208.0 291.8 234.6 

Subaru 217.9 272.2 237.5 

Suzuki 210.0 276.8 227.1 

Tata 251.8 280.1 266.9 

Toyota 223.2 296.3 247.3 

Volkswagen 220.5 297.8 233.9 

Overall 227.2 307.1 254.0 
Results of Proposed and Alternative Standards 

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Table 4-21 2016 Standards by Manufacturer in the 6% Sensitivity Case 

 Standards 

 Cars Trucks Combined 

BMW 208.7 259.4 222.0 

Chrysler 213.4 276.4 241.2 

Daimler 215.8 269.8 233.1 

Ford 210.2 290.1 245.6 

General Motors 210.2 298.1 247.2 

Honda 203.2 256.9 219.2 

Hyundai 203.4 254.6 212.6 

Kia 205.4 264.9 215.1 

Mazda 202.1 247.6 208.7 

Mitsubishi 199.1 245.8 204.7 

Nissan 207.0 279.8 227.6 

Porsche 186.4 262.9 210.7 

Subaru 196.3 243.3 213.3 

Suzuki 188.5 247.9 203.6 

Tata 230.2 251.2 241.4 

Toyota 201.7 267.4 223.3 

Volkswagen 198.9 268.9 211.1 

Overall 205.7 278.2 230.0 

4.9 Assessment of Manufacturer Differences 

The levels of requisite technologies shown above differ significantly across the 

various manufacturers. This is to be expected for universal, or flat fuel economy or CO2 

standards, since manufacturers’ sales mixes differ dramatically in average size. However, use 

of footprint-based standards should eliminate the effect of vehicle size, and thus, market mix, 

on the relative stringency of a standard across manufacturers. Yet, large differences remain in 

the level of technology projected to be required for various manufacturers to meet the 

proposed standards. Therefore, several analyses were performed to ascertain the cause of 

these differences. Because the baseline case fleet consists of 2008 MY vehicle designs, these 

analyses were focused on these vehicles, their technology and their CO2 emission levels. 

Manufacturers’ average CO2 emissions vary for a wide range of reasons. In addition 

to widely varying vehicle styles, designs, and sizes, manufacturers have implemented fuel 

efficient technologies to varying degrees, as indicated in Table 4-22 below. 
Regulatory Impact Analysis 

4-34 

Table 4-22 Penetration of Technology in 2008 Vehicles with 2016 Sales: Cars and Trucks 

 GDI 

GDI+ 

Deac 

GDI+ 

Turbo Diesel 

6 Speed 

or CV 

Trans 

Dual 

Clutch 

Trans 

StartStop Hybrid 

BMW 6.70% 0.00% 0.00% 0.00% 98.80% 0.80% 0.00% 0.10% 

Chrysler 0.00% 0.00% 0.00% 0.00% 27.90% 0.00% 0.00% 0.00% 

Daimler 6.20% 0.00% 0.00% 6.20% 74.70% 11.40% 0.00% 0.00% 

Ford 0.60% 0.00% 0.00% 0.00% 28.10% 0.00% 0.00% 0.00% 

General Motors 3.30% 0.00% 0.00% 0.00% 13.70% 0.00% 0.10% 0.10% 

Honda 1.20% 0.00% 0.00% 0.00% 4.20% 0.00% 0.00% 2.10% 

Hyundai 0.00% 0.00% 0.00% 0.00% 4.90% 0.00% 0.00% 0.00% 

Kia 0.00% 0.00% 0.00% 0.00% 0.90% 0.00% 0.00% 0.00% 

Mazda 11.80% 0.00% 0.00% 0.00% 37.10% 0.00% 0.00% 0.00% 

Mitsubishi 0.00% 0.00% 0.00% 0.00% 76.10% 0.00% 0.00% 0.10% 

Nissan 17.70% 0.00% 0.00% 0.00% 33.30% 0.00% 0.00% 0.00% 

Porsche 0.00% 0.00% 0.00% 0.00% 3.90% 0.00% 0.00% 0.00% 

Subaru 0.00% 0.00% 0.00% 0.00% 29.00% 0.00% 0.00% 0.00% 

Suzuki 0.00% 0.00% 0.00% 0.00% 100.00% 0.00% 0.00% 0.00% 

Tata 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

Toyota 7.50% 0.00% 0.00% 0.00% 30.60% 0.00% 0.00% 12.80% 

Volkswagen 52.20% 0.00% 0.00% 0.10% 82.80% 10.90% 0.00% 0.00% 

Overall 6.40% 0.00% 0.00% 0.10% 27.10% 0.60% 0.00% 2.80% 

Once significant levels of technology are added to these vehicles in order to comply 

with future standards, the impact of existing technology diminishes dramatically. 

Manufacturers which did not utilize much technology in 2008 essentially catch up to those 

which did. The exception is the use of hybrid technology in 2008, since hybrids are not 

projected to be needed by most manufacturers to meet the proposed standards. This primarily 

affects Toyota, and to a lesser extent, Honda. Their use of hybrid technology in their 2008 

fleet will continue to provide relatively greater CO2 reductions even in the 2016 projections. 

As long as the vehicle designs of various manufacturers would produce the same level of CO2 

emissions if their CO2 reducing technology was removed, for the most part, difference in the 

application of technology in 2008 will not affect the level of technology needed in 2016. 

In addition, as mentioned above, differences in CO2 emissions due to differences the 

distribution of sales by vehicle size should be largely eliminated by the use of a footprintbased standard. Thus, just because a manufacturer produces larger vehicles than another 

manufacturer does not explain the differences in required technology seen above. 

In order to focus this analysis on the 2008 MY fleet, it would be helpful to remove the 

effect of differences in vehicle size and the use of CO2 reducing technology, so that the other 
Results of Proposed and Alternative Standards 

4-35 

causes of differences can be highlighted. EPA used the EPA lumped parameter model 

described in Chapter 1 to estimate the degree to which technology present on each 2008 MY 

vehicle was improving fuel efficiency. The effect of this technology was then removed from 

each vehicle to produce CO2 emissions which did not reflect any differences due to the use of 

CO2 reducing technology. This set of adjusted CO2 emission levels is referred to as “no 

technology” emissions. 

The differences in the relative sizes of vehicles sold by each manufacturer were 

accounted for by determining the difference between the sales-weighted average of each 

manufacturer’s “no technology” CO2 levels and their required CO2 emission level under the 

proposed 2016 standards. This difference is the total reduction in CO2 emissions required for 

each manufacturer relative to a “no technology” baseline. The same difference for the 

industry as a whole is 71 g/mi CO2 for cars and 1.7 g/mi CO2 for trucks. This industry-wide 

difference was subtracted from each manufacturer’s difference to highlight which 

manufacturers had lower and higher CO2 emission reduction requirements. The results are 

shown in Figure 4-1. 

-60

-40

-20

0

20

40

60

80

100

120

BMW

Chrysler

Daimler

Ford

GeneralMotors

Honda

Hyundai

Kia

Mazda

Mitsubishi

Nissan

Porsche

Subaru

Suzuki

Tata

Toyota

Volkswagen

CO2 Emissions (g/mi)

Car

Truck

Figure 4-1 CO2 Emissions Relative to Fleet Adjusted for Technology and Footprint 

As can be seen, the manufacturers projected in Table 4-22 to require the greatest levels 

of technology also show the highest offsets relative to the industry. The greatest offset shown 

in Figure 4-1 is for Tata’s trucks (Land Rover). These vehicles are estimated to have 100 
Regulatory Impact Analysis 

4-36 

g/mi greater CO2 emissions than the average 2008 MY truck after accounting for differences 

in the use of fuel saving technology and footprint. The lowest adjustment is for Subaru’s 

trucks, which have 50 g/mi CO2 lower emissions than the average truck. 

While this comparison confirms the differences in the technology penetrations shown 

in Table 4-22, it does not yet explain why these differences exist. Two well known factors 

affecting vehicle fuel efficiency are vehicle weight and performance. The footprint-based 

form of the proposed CO2 standard accounts for most of the difference in vehicle weight seen 

in the 2008 MY fleet. However, even at the same footprint, vehicles can have varying 

weights. Also, higher performing vehicles also tend to have higher CO2 emissions over the 

two-cycle test procedure. So manufacturers with higher average performance levels will tend 

to have higher average CO2 emissions for any given footprint. Table 4-23 shows each 

manufacturer’s average ratios of weight to footprint and horsepower to weight. 

Table 4-23 Vehicle Weight to Footprint and Performance 

 Car Truck 

Manufacturer 

Weight / 

Footprint 

(lb/sq ft) 

Horsepower/ 

Weight 

(hp/lb) 

Weight / 

Footprint 

(lb/sq ft) 

Horsepower/ 

Weight (hp/lb) 

BMW 78 0.073 94 0.059 

Chrysler 74 0.054 85 0.053 

Daimler 73 0.068 97 0.057 

Ford 77 0.057 84 0.052 

General Motors 76 0.057 83 0.059 

Honda 67 0.051 83 0.055 

Hyundai 70 0.052 84 0.056 

Kia 67 0.05 79 0.057 

Mazda 73 0.05 80 0.055 

Mitsubishi 74 0.052 83 0.056 

Nissan 72 0.059 80 0.058 

Porsche 82 0.106 96 0.073 

Subaru 73 0.057 79 0.054 

Suzuki 70 0.049 81 0.062 

Tata 78 0.077 110 0.057 

Toyota 71 0.054 80 0.062 

Volkswagen 80 0.059 108 0.052 

Overall 73 0.056 83 0.058 

The impact of these two factors on each manufacturer’s “no technology” CO2

emissions was estimated. First, the “no technology” CO2 emissions levels were statistically 
Results of Proposed and Alternative Standards 

4-37 

analyzed to determine the average impact of weight and the ratio of horsepower to weight on 

CO2 emissions. Both factors were found to be statistically significant at the 95 percent 

confidence level. The results of the statistical analysis are summarized in Table 4-24. 

Table 4-24 Effect of Weight and Performance on “No Technology” Vehicle CO2 

 Intercept 

(g/mi CO2) 

Effect of 

weight 

(g/mi 

CO2/lb) 

Effect of 

Horsepower / 

Weight (g/mi 

CO2*lb/hp) 

R-Square 

Car -45.8 0.0819 1590 0.82 

Truck -21 0.0782 1838 0.71 

Together, these two factors explain over 80 percent of the variability in vehicles’ CO2

emissions for cars and over 70 percent for trucks. These relationships were then used to 

adjust each vehicle’s “no technology” CO2 emissions to the average weight for its footprint 

value and to the average horsepower to weight ratio of either the car or truck fleet, as follows: 

For Cars: 

CO2 Emissions adjusted for weight and performance = “No Technology” CO2 - 

 (Vehicle Weight - Vehicle Footprint * 73) * 0.0819 – 

 (Vehicle hp/wt – 0.056 ) * 1590 

For Truck: 

CO2 Emissions adjusted for weight and performance = “No Technology” CO2 - 

 (Vehicle Weight - Vehicle Footprint * 83) * 0.0782 – 

 (Vehicle hp/wt – 0.058 ) * 1838 

We then recomputed the difference between the sales-weighted average of each 

manufacturer’s adjusted “no technology” CO2 levels and their required CO2 emission level 

under the proposed 2016 standards and subtracted the difference for the industry as a whole. 

The results are shown in Figure 4-2. 
Regulatory Impact Analysis 

4-38 

-40

-30

-20

-10

0

10

20

30

40

BMW

Chrysler

Daimler

Ford

GeneralMotors

Honda

Hyundai

Kia

Mazda

Mitsubishi

Nissan

Porsche

Subaru

Suzuki

Tata

Toyota

Volkswagen

CO2 Emissions (g/mi)

Car

Truck

Figure 4-2 CO2 Emissions Relative to Fleet Adjusted for Technology, Footprint, Weight at Footprint, and 

Performance 

First, note that the scale in Figure 4-2 is much smaller by a factor of 3 than that in 

Figure 4-1. In other words, accounting for differences in vehicle weight (at constant 

footprint) and performance dramatically reduces the differences in various manufacturers’ 

CO2 emissions. Most of the manufacturers with high offsets in Figure 4-1 now show low or 

negative offsets. For example, BMW’s and VW’s trucks show very low CO2 emissions. 

Tata’s emissions are very close to the industry average. Daimler’s vehicles are no more than 

10 g/mi above the average for the industry. This analysis indicates that the primary reasons 

for the differences in technology penetrations shown for the various manufacturers in Table 

4-24 are weight and performance. EPA has not determined why some manufacturer’s vehicle 

weight is relatively high for its footprint value, nor whether this weight provides additional 

utility for the consumer. Performance is more straightforward. Some consumers desire high 

performance and some manufacturers orient their sales towards these consumers. However, 

the cost in terms of CO2 emissions is clear. Producing relatively heavy or high performance 

vehicles increases CO2 emissions and will require greater levels of technology in order to 

meet the proposed CO2 standards. 
Emissions Impacts 

5-1 

CHAPTER 5:Emissions Impacts 

5.1 Overview 

The domestic transportation sector emits approximately 28% of total U.S. greenhouse gas 

(GHG) emissions in 2010 based on the standard accounting methodology used by EPA in 

compiling the inventory of U.S. GHG emissions pursuant to the United Nations Framework 

Convention on Climate Change. This number is potentially even higher, as the standard 

methodology excludes upstream transportation fuel emissions associated with extraction, 

shipping, refining, and distribution from the emissions of the transportation sector. Within the 

transportation sector, emissions from light duty vehicles such as passenger cars, passenger 

trucks, and light duty commercial trucks account for 18% of total US GHG emissions, or 

approximately 1,300 million metric tons (MMT) of CO2 equivalent (CO2 EQ) greenhouse gas 

emissions in calendar year 2010. 

Today’s proposal quantifies anticipated impacts from the EPA vehicle CO2 emission 

standards. The emissions from the GHGs carbon dioxide (CO2), methane (CH4), nitrous 

oxide (N2O) and hydrofluorocarbons (HFCs) were quantified. In addition to reducing the 

emissions of greenhouse gases, today’s proposal would also influence the emissions of 

“criteria” air pollutants, including carbon monoxide (CO), fine particulate matter (PM2.5) and 

sulfur dioxide (SOx) and the ozone precursors hydrocarbons (VOC) and oxides of nitrogen 

(NOx); and air toxics (hazardous air pollutants, including benzene, 1,3-butadiene, 

formaldehyde, acetaldehyde, and acrolein). 

Downstream (tailpipe) emission impacts were developed using a spreadsheet analysis 

based on data from two EPA models. Computation algorithms and achieved CO2 levels were 

derived from EPA’s Optimization Model for reducing Emissions of Greenhouse gases from 

Automobiles (OMEGA) and were coupled with non-CO2 emission rates from EPA’s Motor 

Vehicle Emission Simulator (MOVES). 

Upstream (fuel production and distribution) emission changes resulting from the 

decreased fuel consumption predicted by the downstream models were calculated using a 

spreadsheet model based on emission factors from GREET.1

 Based on these analyses, the 

control programs proposed in this chapter would account for 325 MMT CO2EQ of annual 

GHG reduction by the year 2030 and 519 MMT per year by 2050. Fuel savings resulting 

from the GHG standards are projected at 42.6 billion gallons of fuel savings in Calendar Year 

2050 (Table 5-1). 
Draft Regulatory Impact Analysis 

5-2 

Table 5-1 - Impacts of Proposed Program on GHG Emissions and Fuel Savings 

CALENDAR 

YEAR 

ANNUAL GHG 

REDUCTION (CO2

EQ MMT) 

FUEL SAVINGS 

(MILLION BARRELS 

PER DAY OF 

GASOLINE 

EQUIVALENT) 

ANNUAL FUEL 

SAVINGS 

(BILLION GALLONS 

OF GASOLINE 

EQUIVALENT) 

2020 165.2 0.9 13.4 

2030 324.6 1.7 26.2 

2040 417.5 2.2 33.9 

2050 518.5 2.8 42.6 

The emissions of non-GHG air pollutants due to light duty vehicles are also expected 

to be affected by today’s proposal. These effects are largely due to changes in fuel 

production, but are also driven by changes in driver behavior.A The delta values shown here 

include both upstream and downstream contributions. 

Table 5-2 - Impacts of Proposed Program on Non-GHG Emissions (Short Tons per year) 

POLLUTANT 

CALENDAR 

YEAR 

2020 

% 

CHANGE 

VS. 2020 

REFEREN

CE 

CALEND

AR YEAR

2030 

% 

CHANGE 

VS. 2030 

REFEREN

CE

Δ 1,3-Butadiene 11.5 0.07% 36.8 0.22% 

Δ Acetaldehyde 16.8 0.037% 60.6 0.134% 

Δ Acrolein 0.2 0.00% 1.8 0.03% 

Δ Benzene -83.6 -0.04% -77.5 -0.04% 

Δ Carbon Monoxide 70,614 0.13% 227,832 0.38% 

Δ Formaldehyde -28.3 -0.03% -15.7 -0.02% 

Δ Oxides of Nitrogen -17,206 -0.14% -27,726 -0.23% 

Δ Particulate Matter 

(below 2.5 micrometers) 

-2,856 -0.08% -5,431 -0.16% 

Δ Oxides of Sulfur -16,307 -0.18% -31,965 -0.34% 

Δ Volatile Organic Compounds -73,739 -0.60% -142,347 -1.17% 

We also analyzed the emission reductions over the full model year lifetime of the 2012-

2016 model year cars and trucks affected by today’s proposal. These results, including both 

upstream and downstream GHG contributions, are presented below (Table 5-3). 

 A A rebound of 10% is used in this analysis. See section 5.3.3.1.1 for a brief definition of rebound, and the joint 

Technical Support Document for a more complete discussion. 
Emissions Impacts 

5-3 

Table 5-3 - Model Year Lifetime Fuel Savings and GHG Reductions 

Model Year Lifetime GHG 

Reduction 

(MMT CO2 EQ) 

Lifetime Fuel Savings

(Billion Gallons Of 

Gasoline Equivalent) 

Lifetime Fuel Savings 

(Million Barrels of 

Gasoline Equivalent) 

2012 81 6.6 157 

2013 125 10.0 239 

2014 174 13.9 331 

2015 243 19.5 463 

2016 323 26.3 626 

Total 

Program 

Benefit 

947 76.2 1,815 

5.2 Introduction 

5.2.1 Scope of Analysis 

Today’s program proposes new standards for the greenhouse gas (GHG) emissions of 

light duty vehicles from model year 2012 through model year 2016. The proposed program 

affects light duty gasoline and diesel fueled vehicles. Most passenger vehicles such as cars, 

sport utility vehicles, vans, and pickup trucks are light duty vehicles. Such vehicles are used 

for both commercial and personal uses and are significant contributors to the total United 

States (U.S.) GHG emission inventory. Today’s proposal will significantly decrease the 

magnitude of these emissions. Because of anticipated changes to driving behavior and fuel 

production, a number of co-pollutants would also be affected by today’s proposal. 

This chapter describes the development of inventories for emissions of the gaseous 

pollutants impacted by the proposed rule. These pollutants are divided into greenhouse gases, 

or gases that in an atmosphere absorb and emit radiation within the thermal infrared range, 

and non-greenhouse gases. Such impacts may occur "upstream" in the agricultural sector and 

fuel production and distribution processes, or "downstream" in direct emissions from the 

transportation sector. Table 5-4 presents the processes considered in each domain. This 

analysis presents the projected impacts of today’s proposal on greenhouse gases in calendar 

years 2020, 2030, 2040 and 2050. Non-greenhouse gases are shown in 2020 and 2030. The 

program was quantified as the difference in mass emissions between the proposed standards 

and a reference case as described in Section 5.3.2.2. 
Draft Regulatory Impact Analysis 

5-4 

 

Table 5-4 - Processes Considered 

PROCESS UPSTREAM / DOWNSTREAM 

Crude Oil Extraction Upstream 

Crude Oil Transport Upstream 

Oil Refining Upstream 

Fuel Transport and Distribution Upstream 

Fuel Tailpipe Emissions Downstream 

Air Conditioning System Leakage Downstream 

Delta inventories for the four greenhouse gases carbon dioxide (CO2), methane (CH4), 

nitrous oxide (N2O) and hydrofluorocarbons (HFC) are presented herein. The sole HFC 

discussed in this inventory is R-134a, which is the refrigerant in most current vehicle air 

conditioning systems. Delta inventories for the non-ghg pollutants 1,3-butadiene, 

acetaldehyde, acrolein, benzene, carbon monoxide (CO), formaldehyde, oxides of nitrogen 

(NOx), particulate matter below 2.5 micrometers, oxides of sulfur (SOx), and volatile organic 

compounds (VOC) are also presented. 

5.2.2 Downstream Contributions 

The largest source of GHG reductions from today’s proposal is new standards for 

tailpipe emissions produced during vehicle operation (termed “downstream” emissions). 

Absolute reductions from tailpipe GHG standards are projected to grow over time as the fleet 

turns over to vehicles affected by the standards, meaning the benefit of the program will 

continue to grow as long as the older vehicles in the fleet are replaced by newer, lower CO2

emitting vehicles. 

As described herein, the downstream reductions in greenhouse gases due to the proposed 

program are anticipated to be achieved through improvements to both fuel economy and air 

conditioning system operation. Improvements to air conditioning systems can be further 

separated into reducing leakage of HFCs (direct improvement) and reducing fuel consumption 

by increasing the efficiency of the air conditioning system (indirect). 

Due to the rebound effect, improving fuel economy is anticipated to increase total vehicle 

miles traveled, which has impacts on both GHG and non-GHG emissions. These impacts are 

detailed in Section 5.3.3.1.1 

5.2.3 Upstream Contributions 

In addition to downstream emission reductions, reductions are expected in the 

emissions associated with the processes involved in getting petroleum to the pump, including 

the extraction and transportation of crude oil, and the production and distribution of finished 

gasoline (termed “upstream” emissions). Changes are anticipated in upstream emissions due 

to the expected reduction in the volume of fuel consumed. Less gasoline consumed means 

less gasoline transported, less gasoline refined, and less crude oil extracted and transported to 
Emissions Impacts 

5-5 

refineries. Thus, there should be reductions in the emissions associated with each of these 

steps in the gasoline production and distribution process. 

HFC manufacture is not considered a significant source of upstream emissions and is not 

considered in this analysis.2

5.2.4 Global Warming Potentials 

Throughout this document, in order to refer to the four inventoried greenhouse gases on 

an equivalent basis, Global Warming Potentials (GWPs) are used. In simple terms, GWPs 

provide a common basis with which to combine several gases with different heat trapping 

abilities into a single inventory (Table 5-5). When expressed in CO2 equivalent (CO2 EQ) 

terms, each gas is weighted by its heat trapping ability relative to that of carbon dioxide. The 

GWPs used in this chapter are drawn from publications by the Intergovernmental Panel on 

Climate Change (IPCC).3,B

Table 5-5 - Global Warming Potentials for the Inventory GHGs 

Gas Global Warming potential 

(CO2 Equivalent) 

CO2 1 

CH4 25 

N2O 298 

HFC (R134a) 1430 

5.3 Program Analysis and Modeling Methods 

5.3.1 Models Used 

The inventories presented in this document were developed from established EPA 

models. 

Downstream inventories were generated using algorithms from EPA’s Optimization 

Model for reducing Emissions of Greenhouse gases from Automobiles (OMEGA). Broadly 

 

B

 The global warming potentials (GWP) used in the NPRM inventory analysis are consistent with 

Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). At this time, the IPCC 

Second Assessment Report (SAR) global warming potential values have been agreed upon as the official U.S. 

framework for addressing climate change. The IPCC SAR GWP values are used in the official U.S. greenhouse 

gas inventory submission to the United Nations climate change framework. When inventories are recalculated 

for the final rule, changes in GWP used may lead to adjustments. 
Draft Regulatory Impact Analysis 

5-6 

speaking, OMEGA is used to determine the most likely paths by which manufacturers would 

meet tailpipe CO2 emission standards. OMEGA applies technologies with varying degrees of 

cost and effectiveness to a defined vehicle fleet in order to meet a specified GHG emission 

target and calculates the costs and benefits of doing so. The benefits analyses in OMEGA are 

conducted in a Microsoft Excel Workbook (the benefits post-processor). The OMEGA 

benefits post-processor produces a national scale analysis of the benefits (emission reductions, 

monetized co-benefits) of the analyzed program 

Inputs to the OMEGA post-processor were updated with emission rates from EPA’s 

Motor Vehicle Emission Simulator (MOVES).45 CO2 emission and fuel consumption rates 

are drawn from OMEGA results, with all co-pollutant emission rates derived from the Draft 

MOVES emission rate database. C,6 Air conditioning inventories (including HFC and CO2

contributions) were separately calculated in spreadsheet analyses, and are based on previous 

EPA research.7

 Both MOVES and OMEGA are established models and continue to be 

actively developed. 8,9

Upstream emissions were calculated using the same tools as were used for the 

Renewable Fuel Standard 2 (RFS2) proposed rule analysis,10 but for the current analysis it 

was assumed that all impacts are related to changes in volume of gasoline produced and 

consumed, with no changes in volumes of other petroleum-based fuels, ethanol, or other 

renewable fuels. The estimate of emissions associated with production of gasoline from crude 

oil is based on emission factors in the GREET model developed by DOE's Argonne National 

Lab.11, 12 The actual calculation of the emission inventory impacts of the decreased gasoline 

production is done in EPA's spreadsheet model for upstream emission impacts. This model 

uses the decreased volumes of the crude based fuels and the various crude production and 

transport emission factors from GREET to estimate the net emissions impact. As just noted, 

the analysis for today's proposal assumes that all changes in volumes of fuel used affect only 

gasoline, with no effects on use of other petroleum-based fuels, ethanol, or other renewable 

fuels. 

The following sections provide an in-depth description of the inputs and methodology 

used in each analysis. 

5.3.2 Description of Scenarios 

One reference and one control scenario are modeled in this proposal, and each is 

described below.13 The two scenarios shown are differentiated by their regulatory CO2

emission standards. The reference scenario CO2 emissions are based upon the National 

Highway Traffic Safety Administration (NHTSA) Model Year 2011 Corporate Average Fuel 

Economy (CAFE) standards,14 while the control scenario CO2 emissions are based upon the 

program proposed herein. Otherwise, the scenarios share fleet composition, sales, base 

vehicle miles traveled (VMT), and all other relevant aspects. Vehicles are modeled as 

compliant with Tier 2 criteria emission standards. 

 C

 Two tables were updated in the Draft MOVES database. These tables are available in the docket. 
Emissions Impacts 

5-7 

Ethanol use was modeled at the volumes projected in AEO2007 for the reference and 

control case; thus no changes are projected in upstream emissions related to ethanol 

production and distribution. However, due to the decreased gasoline volume associated with 

today's proposal, a greater market share of E10 is expected relative to E0, which would be 

expected to have some effect on fleetwide average non-GHG emission rates. The increased 

market share of ethanol blended gasoline, which is likely small relative to the other effects 

considered here, has not been accounted for in the downstream emission modeling conducted 

for today's proposal, but is planned to be addressed in the final rule air quality analysis, for 

which localized impacts could be more significant. Due to the lower energy content of 

ethanol blended gasoline, the increase in ethanol market share is also projected to decrease the 

fuel savings predicted by this analysis by approximately 1-2%. A more comprehensive 

analysis of the impacts of different ethanol and gasoline volume scenarios is being prepared 

as part of EPA's RFS2 rulemaking package.D 

5.3.2.1 Sales and Fleet Composition 

Fleet composition has a significant effect upon the impacts of the proposed rule. 

Consequently, it is significant that the cars and trucks in this analysis are defined differently 

than their historic EPA classifications. Passenger Automobiles (PA), as used herein, are 

defined as classic cars and two-wheel drive SUVs below 6,000 lbs. gross vehicle weight. The 

remaining light duty fleet is defined as Non-Passenger Automobiles (NPA). The NPA 

classification includes most classic light duty trucks such as four-wheel drive SUVs, pickup 

trucks, and similar vehicles. 

As shown in Table 5-6, the vehicle classifications used herein are consistent with the 

definitions used by the National Highway Safety Transit Association in the MY 2011 CAFE 

standards.15 While the formal definitions are lengthy, brief summaries of the classifications 

are shown here. 

Table 5-6 -Definitions of Vehicle Classes 

REGULATOR CAR DEFINITION TRUCK DEFINITION 

National Highway Traffic 

Safety Administration CAFE 

Program (pre-MY 2011) 

Classic Car – Passenger Car Classic Truck – Light Duty Trucks 1-4 and 

Medium Duty Passenger Vehicles. 

EPA Program 

(MY 2012+) 

Passenger Automobile – PC 

+ 2 wheel drive SUVs below 

6,000 GVW 

Non-Passenger Automobile – Remaining 

light duty fleet 

Based on EPA analysis of the projected MY 2012-2016 fleet,16 approximately 22% of 

the classic truck fleet is anticipated to be reclassified as Passenger Automobiles under the new 

standards. Projected sales of classic cars and trucks for calendar years 2012-2030 were drawn 

from the Energy Information Administration Annual Energy Outlook (AEO) April 2009 

projection.17 The AEO 2009 sales projections, based on the classic fleet, were then 

 D XX [Insert RFS2 NPRM reference, since FRM will not be available in time for GHG NPRM.] 
Draft Regulatory Impact Analysis 

5-8 

reclassified using PA and NPA definitions. For calendar years 2030-2050, which are beyond 

the scope of AEO’s projections, 0.76% annual growth in the sales of cars and trucks was 

assumed. 

Table 5-7 – Projected Total Vehicle Sales and Car Fractions 

Model Year 

2012 

Model Year 

2013 

Model Year 

2014 

Model Year 

2015 

Model Year 

2016 

Total Light 

Duty Sales 

 

14,850,955 15,653,713 16,216,393 16,575,580 

 

16,581,055 

Classic Car 

Fraction 

51.8% 52.9% 54.3% 55.8% 57.1% 

PA Fraction 62.6% 63.6% 64.3% 65.6% 66.5% 

PAs Sold 8,235,204 9,255,624 9,977,341 10,479,350 10,890,967 

5.3.2.2 Proposed Standards 

Individual PA and NPA tailpipe CO2 fleet average emission standards are shown for 

reference and control scenarios along with an anticipated fleet average combined standard. 

Rather than an absolute standard, the values referred to here as standards are the production 

weighted average standard predicted by the coefficients of the relevant equation. As 

documented in Preamble section II, under both reference and control scenarios, each 

manufacturer has a unique fleet average standard based on their vehicle footprints and 

production. 

Fleet average standards are calculated here by weighting the individual PA and NPA 

standards by the respective proportions of anticipated production (Section 5.3.2.1). These 

CO2 emission values are unadjusted values (i.e. in CAFE space), so they are lower than the 

anticipated on-road emissions. In all scenarios, vehicles are assumed to maintain model year 

2016 emissions for post-2016 vehicles. Because the fleet composition continues to change 

post-MY 2016, the fleet average emission level continues to vary 

5.3.2.2.1 Reference Case 

5.3.2.2.1.1 CO2 Emission Standards 

The reference scenario standards were derived from the NHTSA model year 2011 

Corporate Average Fuel Economy (CAFE) standards applied to the MY 2012-2016 reference 

fleet (see chapter 1 of the draft joint TSD and chapter 4 of this DRIA).18 Average car and 

truck fuel economy standards were calculated from the coefficients in the MY 2011 rule and 

EPA analysis of the projected MY 2012-2016 fleet.19,20 Average fuel economy levels were 

calculated for each manufacturer’s fleet, and then combined based on projected sales. 
Emissions Impacts 

5-9 

A ratio of 8887 grams of CO2 emitted per gallon of gasoline was used to convert to the 

calculated fuel economy standards to CO2 (gram/mile) emission factors. The basic derivation 

of the 8887 factor can be seen in previous EPA publications.21

CO2 emission standards were calculated by applying the CAFE coefficients to the 

footprint of each model, and calculating fleet averages based on projected model sales. 

Minor changes in the emission standard are expected due to projected changes in the average 

new vehicle footprint between 2012 and 2016 (Table 5-8). 

Table 5-8 – Reference Case Average Emission Standards (grams/mile CO2) 

MODEL 

YEAR 

PA 

EMISSION 

LEVEL 

NPA EMISSION 

LEVEL 

MY EMISSION 

LEVEL 

2012 291 366 319 

2013 291 366 319 

2014 291 368 319 

2015 291 368 318 

2016 291 368 317 

5.3.2.2.1.2 Achieved CO2 Emission Levels 

The emission standards shown in Table 5-8 do not reflect the impact of several 

program flexibilities in CAFE, nor do they account for manufacturer overcompliance. 

Projected achieved emission levels include the effects of manufacturers who pay fines rather 

than comply with the emission standards, as well as a number of credit programs under 

EPCA/EISA that allow manufacturers to emit more than the standard seemingly requires. 

Additionally, some manufacturers overcomply with the standards, and this overcompliance is 

not reflected in the CAFE standards. 

While the CAFE program is complex, the most significant portions of the program 

flexibilities are accounted for. In this analysis, manufacturer overcompliance, credit trading, 

FFV credits, and fine paying manufacturers were accounted for. Banked credits from the 

calculation of achieved standards were excluded. 

In general, achieved emission levels were estimated by beginning with the more 

stringent of either (A) manufacturer’s CAFE score (in CO2 space) or (B) estimated achieved 

MY 2008 CO2 level based on the EPA fleet data file. Using that starting point, each 

manufacturer’s emissions was increased by the impact of the credits of which is anticipated 

that they will take advantage. Consistent with the use of the MY 2011 standards, the credits 

and trading levels available for MY 2011 are assumed available in all years of the reference 

case. Manufacturers were always assumed to perform at least as well as they did in 2008. 

Overcompliance and Credit Trading 
Draft Regulatory Impact Analysis 

5-10 

Using the EPA fleet file, the fleet mix was estimated by manufacturer for model year 

2012 through model year 2016. For each model year, the CAFE score (in CO2 space) was 

calculated by manufacturer for PA and NPA separately. To estimate the effects of 

overcompliance, each manufacturer’s achieved 2008 PA/NPA emissions were compared 

against the PA/NPA emissions required by CAFE in 2011. 

The overcompliance on either PA or NPA could be “traded” within a manufacturer in 

order to make up a shortfall in the remaining vehicle class. Credits are generated on a sales 

and VMT weighted basis, and traded between vehicle classes. The MY 2011 CAFE cap on 

credit trading of 1.0 mpg was used. This trading of the overcompliance credit negates some, 

but not all of the overcompliance anticipated. Certain manufacturers, such as Toyota and 

Honda, overcomply by a great deal more than they are able to trade between vehicle classes. 

Flex Fueled vehicle Credits

The 2007 Energy Independence and Security Act allows for CAFE credits due to 

production of “flex-fueled” vehicles. Under the model year 2011 standards, such credits can 

be used to meet up to 1.2 MPG of the CAFE standard. The manufacturers General Motors, 

Chrysler and Ford were assumed to take advantage of this credit for both cars and trucks, 

while Nissan was assumed to utilize this credit solely for trucks. 

Fines 

In this analysis, EPA used estimates of fine paying manufacturers from NHTSA’s 

Volpe model. That model supplied projected maximum stringencies that a manufacturer 

would meet before it was more cost effective to pay a non-compliance fine. The 

manufacturers who are projected to pay fines are Tata, Daimler, BMW, Porsche, and 

Volkswagen. 

The projected impacts of these program flexibilities on the standards, achieved levels 

based on program flexibilities and manufacturer overcompliance are shown in Table 5-10. 

Table 5-9 - Impacts of credits (grams/mile CO2 EQ) 

MODEL 

YEAR 

OVERCOMPLIANCE, 

CREDITS AND 

TRADING 

FFV FINES NET 

2012 -6.1 6.7 0.7 1.2

2013 -6.4 6.7 0.2 0.5

2014 -6.8 6.7 0.1 0.0

2015 -7.1 6.5 0.1 -0.5

2016 -7.3 6.4 0.0 -0.9
Emissions Impacts 

5-11 

Table 5-10 – Reference Case Achieved Emissions (grams/mile CO2) 

MODEL 

YEAR 

ANTICIPATED 

PA EMISSION 

LEVEL 

ANTICIPATED 

NPA EMISSION 

LEVEL 

ANTICIPATED 

MY EMISSION 

LEVEL 

2012 284 382 320 

2013 283 382 319 

2014 283 383 319 

2015 282 384 317 

2016 282 384 316 

5.3.2.2.2 Control Case 

5.3.2.2.2.1 CO2 Emission Standards 

Similar to the reformed CAFE program, EPA is proposing to establish a footprint 

attribute based function in order to determine the CO2 (gram/mile) emission standard for a 

given vehicle. The piecewise linear function used by EPA is documented in Section II of the 

preamble. Based on this function, and the same vehicle fleet as was used in the reference 

scenario, EPA calculated projected PA and NPA fleet average emission standards for the 

MY2012-2016 vehicles. Average PA and NPA fuel economy standards were calculated by 

applying this function to the EPA fleet file (Table 5-11).22 

 Table 5-11 - Control Case Average Emission Standards (grams/mile CO2) 

MODEL 

YEAR 

PA 

EMISSION 

LEVEL 

NPA EMISSION 

LEVEL 

PROJECTED 

MY EMISSION 

STANDARD 

LEVEL 

2012 261 351 295 

2013 253 341 286 

2014 246 332 276 

2015 235 317 263 

2016 223 302 250 
Draft Regulatory Impact Analysis 

5-12 

 

5.3.2.2.2.2 Achieved CO2 Emission Levels 

Just as with the reference scenario, the emission standards (Table 5-11) do not include 

the effect of several program flexibilities built into the EPA program. 

The same basic methodology was used to calculate achieved fleet standards for the 

control case. In general, achieved standards were estimated by beginning with the more 

stringent of either (A) manufacturer’s calculated footprint-based emission standard or (B) 

estimated achieved CO2 level based on the EPA fleet data file. Using that starting point, each 

manufacturer’s emissions were increased by the impact of the credits of which were 

anticipated that they will take advantage. Manufacturers were always assumed to perform at 

least as well as they did in 2008. 

Overcompliance and Trading

Using the EPA fleet file, the fleet mix was estimated by manufacturer for model year 

2012 through model year 2016. For each model year, the GHG standard was calculated by 

manufacturer for PA and NPA separately. To estimate the effects of overcompliance, each 

manufacturer’s achieved PA/NPA emissions was compared against the PA/NPA emissions 

required by CAFE. 

The achieved overcompliance on either PA or NPA could be “traded” within a 

manufacturer in order to make up a shortfall in the remaining vehicle class. Credits are 

generated on a sales and VMT weighted basis, and traded between vehicle classes. Under the 

EPA proposed program, there are no limits on such trading. This trading of the 

overcompliance credit negates nearly all of the overcompliance anticipated in the early years. 

Under the unlimited within-fleet trading allowed under the EPA program, 

manufacturers can potentially invest in their fleet differently than the precise achieved levels 

described here. Because the credit trading is VMT weighted, the resulting changes will be 

essentially environmentally neutral on both GHG and criteria pollutants. 

Flex Fueled Vehicles

The flex fueled vehicle credit, per the discussion in the preamble (Section III), is set at 

1.2 MPG for MY 2012-2014, 1.0 MPG for MY 2015, and 0 MPG for MY 2016+. As in the 

reference case, it was assumed that the manufacturers General Motors, Chrysler and Ford 

would take advantage of this credit for both cars and trucks, while Nissan would utilize this 

credit solely for trucks. 

A/C

 Indirect A/C credits were set at 5.7 grams CO2 per mile for the fleet, while direct A/C 

credits were set at 6.9 grams CO2 per mile for PA and 8.6 grams CO2 per mile for NPA). 

EPA assumed market penetration of the technology according to Table 5-16. A more 
Emissions Impacts 

5-13 

complete discussion of the A/C credit program and inventories is provided in section 5.3.3.2, 

as well as DRIA chapter 2. 

Temporary Lead Time Allowance Alternative Standards (TLAAS)

 We assumed that every potentially eligible manufacturer took advantage of the 

temporary lead time allowance. Each qualifying manufacturer was assumed to use the full 

vehicle allocation according to the default production schedule shown in Preamble Section III. 

The allocation was split evenly between cars and trucks for each manufacturer. This vehicle 

allocation was assumed to emit as much CO2 per mile as the highest emitting car or truck in 

each manufacturer’s fleet. These vehicles were then proportionally averaged into the 

manufacturer’s GHG score. For more on the TLAAS program, please see Appendix A to this 

RIA chapter. 

The aggregate impacts of these program flexibilities are listed in Table 5-12. 

Table 5-12 – Estimated Impacts of Proposed Program Flexibilities (grams/mile CO2 EQ) 

MODEL 

YEAR 

OVERCOMPLIANCE, 

CREDITS AND 

TRADING 

FFV DIRECT 

A/C 

INDIRECT 

A/C 

TLAAS NET 

2012 0.1 6.0 1.9 1.4 0.3 9.6 

2013 -0.3 5.7 3.0 2.3 0.2 10.9 

2014 0.0 5.4 4.1 3.1 0.2 12.7 

2015 0.0 4.1 5.6 4.3 0.1 14.0 

2016 0.0 0.0 6.3 4.8 0.0 11.1 

Based on these impacts, the achieved emission level by PA, NPA and fleet are 

displayed in Table 5-13. Please note that the achieved emission levels include the increase in 

test procedure emissions due to the use of the A/C credit. The impacts of A/C improvements 

are discussed in section 5.3.3.2. 

Table 5-13 – Federal GHG Program Anticipated Emission Levels (grams/mile CO2) 

MODEL 

YEAR 

ANTICIPATED 

PA EMISSION 

LEVEL 

ANTICIPATED 

NPA EMISSION 

LEVEL 

ANTICIPATED 

MY EMISSION 

LEVEL 

2012 266 368 304 

2013 261 359 297 

2014 256 349 289 

2015 246 335 277 

2016 234 314 261 

Table 5-13 differs slightly from the OMEGA cost-side model results in 2016. 

OMEGA assumes environmentally neutral trading between PA and NPA within a 

manufacturer’s fleet in order to minimize technology costs. Consequently, the distribution of 

fleet emission reductions differs slightly between cars and trucks from that which is shown 
Draft Regulatory Impact Analysis 

5-14 

here. However, because the trading is VMT weighted, it is environmentally neutral and has 

no GHG emissions impacts. 

OMEGA also predicts slight undercompliance in 2016 for several manufacturers, while 

the results presented here assume full compliance. Based on preliminary analysis, the 

OMEGA cost-side results are estimated to produce approximately 0.5% less GHG benefit. 

5.3.3 Calculation of Downstream Emissions 

The fleet inputs (achieved CO2 emission levels by model year and vehicle 

sales) described above were incorporated into a spreadsheet along with emission rates 

derived from Draft MOVES 2009 and benefits calculations from the OMEGA postprocessor. The resulting spreadsheet projects emission impacts in each calendar year. 

The effects of the program grow over time as the fleet turns over to vehicles subject to 

the more stringent new standards. 

A model year lifetime analysis, considering only the five model years 

regulated underneath the program, is shown in Section 5.6. In contrast to the calendar 

year analysis, the model year lifetime analysis shows the lifetime impacts of the 

program on each MY fleet over the course of that fleet’s existence. 

5.3.3.1 Tailpipe GHG Emissions 

 Two basic elements feed into OMEGA’s calculation of vehicle tailpipe 

emissions. These elements are VMT and emission rates. 

Total Emissions = VMT miles * Emission rate grams/mile

 Equation 3 - Emissions 

This equation is adjusted in calculations for various emissions, but provides the basic 

form used throughout this analysis. As an example, in an analysis of a single calendar year, 

the emission equation is repeatedly applied to determine the contribution of each model year 

in the calendar year’s particular fleet. Appropriate VMT and emission factors are applied to 

each model year within the calendar year. Emissions are then summed across all model years. 

The following sections describe the VMT and emission factor components of this 

analysis. 

5.3.3.1.1 Base VMT 

The downstream analysis is based upon a “bottom-up” estimate of total VMT 

and vehicle population. The VMT inputs are documented more fully in draft joint 

TSD chapter 4, but a description of their use in the emissions calculations are provided 

below. 

The analysis spreadsheet contains MY-specific estimates of per vehicle VMT 

by vehicle age, as well as the fractions of new vehicles still on the road as a function 
Emissions Impacts 

5-15 

of age. The total VMT for vehicles in a specific model year during a specific calendar 

year is determined by multiplying 1) new vehicle sales for that model year, 2) the 

fraction of new vehicles remaining on the road according to the age of those vehicles 

in that calendar year and 3) the annual VMT for that model year, age, and vehicle 

class. 

Future vehicle sales were drawn from AEO 2009 (as discussed in Section 

5.3.2.1), while historic vehicle sales are drawn from the Transportation Energy Data 

Book,23 Post MY 2011 vehicles were reclassified in order to correspond to the 

PA/NPA definitions. 

As described in the draft technical support document, mileage accumulation by 

age was calculated using inputs from the NHTSA “Vehicle Survivability and Travel 

Mileage Schedules” and additional inputs unique to this analysis.24,25 In brief, a 

1.15% per vehicle annual VMT growth rate was assumed, but additional factors such 

as achieved fuel efficiency and the price of gasoline also contributed to the precise 

schedule for each MY. 

The survival schedule was taken without emendation from “Vehicle 

Survivability and Travel Mileage Schedules.” While adjustments may be necessary to 

this schedule to accommodate the change between classic cars/trucks and PA/NPA, 

EPA is unaware of any extant data supporting specific adjustments. Because of the 

lack of data, the survival rates from “Vehicle Survivability and Travel Mileage 

Schedules” were used without further adjustment (Table 5-14).26
Draft Regulatory Impact Analysis 

5-16 

Table 5-14 - Survival Fraction by Age 

AGE PA SURVIVAL 

FRACTION 

NPA 

SURVIVAL 

FRACTION 

0 0.9950 0.9950 

1 0.9900 0.9741 

2 0.9831 0.9603 

3 0.9731 0.9420 

4 0.9593 0.9190 

5 0.9413 0.8913 

6 0.9188 0.8590 

7 0.8918 0.8226 

8 0.8604 0.7827 

9 0.8252 0.7401 

10 0.7866 0.6956 

11 0.7170 0.6501 

12 0.6125 0.6042 

13 0.5094 0.5517 

14 0.4142 0.5009 

15 0.3308 0.4522 

16 0.2604 0.4062 

17 0.2028 0.3633 

18 0.1565 0.3236 

19 0.1200 0.2873 

20 0.0916 0.2542 

21 0.0696 0.2244 

22 0.0527 0.1975 

23 0.0399 0.1735 

24 0.0301 0.1522 

25 0.0227 0.1332 

26 0.0000 0.1165 

27 0.0000 0.1017 

28 0.0000 0.0887 

29 0.0000 0.0773 

30 0.0000 0.0673 

31 0.0000 0.0586 

32 0.0000 0.0509 

33 0.0000 0.0443 

34 0.0000 0.0385 

35 0.0000 0.0334 
Emissions Impacts 

5-17 

A complete discussion of the derivation of the MY specific VMT schedules is 

provided in draft joint TSD chapter 4. 

5.3.3.1.2 Rebound 

The tailpipe CO2 standards are expected to result in greater fuel efficiency. Per 

the discussion of the rebound effect in the draft joint TSD chapter 4, improved fuel 

efficiency is expected to lead to a proportional increase in VMT. Consequently, the 

VMT differs between the reference and control cases. 

The rebound effect is formally defined as the ratio of the percentage change in 

VMT to the percentage change in incremental driving cost, which is typically assumed 

to be the incremental cost of fuel consumed per mile. Since VMT increases with a 

reduction in fuel consumption, the sign of the rebound effect is negative. The 

percentage increase in VMT for a given change in fuel consumption per mile is 

calculated as follows: 

 

old

old new reb FleetFC

FleetFC FleetFC VMT REB  %  *

Equation 4 - VMT Rebound 

As fuel consumption changes by model year, each model year’s vehicles 

reflect a different change in VMT In OMEGA, this change in VMT is assumed to 

continue throughout the life of the vehicle, which is consistent with the assumption 

that fuel economy is constant throughout vehicle life. 

This analysis assumes a 10% rebound effect; the analysis behind 10% is 

explored in greater depth in Chapter 4 of the draft joint TSD. 

5.3.3.1.3 Emission Factors 

The derivation of the emission factors used in this analysis is documented in chapter 4 

of the technical support document. Briefly, CO2 emission rates are derived from the achieved 

vehicle emission levels in Table 5-10 & Table 5-13, SO2 emission rates are derived from fuel 

sulfur levels, and the emission rates for the remaining pollutants are derived from the draft 

MOVES 2009 database. For a more complete discussion of these emission rates, please see 

the draft joint TSD chapter 4.27

EPA is not projecting any reductions in tailpipe CH4 or N2O emissions as a result of 

these proposed emission caps, which are meant to prevent emission backsliding and to bring 

diesel vehicles equipped with advanced technology aftertreatment into alignment with current 

gasoline vehicle emissions. Similar to other pollutants, there are emission impacts due to 

reduced fuel production and increased driving (rebound). 
Draft Regulatory Impact Analysis 

5-18 

5.3.3.1.4 Tailpipe CO2 Emissions from Vehicles 

CO2 emission rates were derived from the achieved levels in Table 5-10 & 

Table 5-13. Previous EPA analysis has shown that an approximately 20% gap exists 

between CAFE space fuel economy and on-road fuel economy.28 The on-road gap is 

more fully documented in the draft joint TSD chapter 4. 

The 20% gap, while approximate, includes average effects of fuel efficiency 

contributors such as road roughness, wind, and high acceleration events. The gap also 

reflects the different energy content between certification fuel and real world fuel 

(which frequently contains some oxygenate or ethanol.), as well as the fuel 

consumption impacts of running a mobile vehicle air conditioning system. In this 

analysis, CO2 emissions are assumed to remain constant throughout the vehicle’s 

lifetime. 

By dividing a CAFE-space CO2 emission rate by (1-on-road gap), one can 

approximate the actual on-road CO2 emissions experienced by drivers. 

On road tailpipe CO2 emissions = 

Achieved CO2 Emission Level /(1-on-road gap) x VMT including rebound 

Equation 5- Tailpipe CO2 Emissions Excluding A/C

Based on Equation 5, the baseline CO2 emissions and change in tailpipe 

emissions due to the new control program were calculated. Emissions due to rebound 

were also calculated. The contributions of the A/C control program are excluded from 

this table. 

Table 5-15 - Tailpipe CO2 Emissions including Baseline A/C Usage (MMT) 

2020 2030 2040 2050 

Tailpipe CO2 Emissions 

(Reference) 1,209 1,373 1,662 2,069 

Δ CO2 Emissions 

(Control) including 10% 

rebound 

-108 -212 -274 -344 

Δ CO2 Emissions due to 

10% rebound 11 21 27 33 

5.3.3.2 Air Conditioning Emissions 

Outside of the tailpipe CO2 emissions directly attributable to driving, EPA has 

analyzed how new control measures might be developed for air conditioning (“A/C”)-related 

emissions of HFCs and CO2. With regard to air conditioning-related emissions, significant 

opportunity exists to reduce HFC emissions from refrigerant leakage (direct emissions) and 

CO2 from A/C induced engine loads (indirect emissions). 
Emissions Impacts 

5-19 

Over 95% of the new cars and light trucks in the U.S. are equipped with A/C systems. 

There are two mechanisms by which A/C systems contribute to the emissions of GHGs. The 

first is through direct leakage of refrigerant (currently the HFC compound R134a) into the air. 

Based on the high GWP of HFCs (Table 5-5), a small leakage of the refrigerant has a greater 

global warming impact than a similar amount of emissions from other mobile source GHGs. 

Leakage can occur slowly through seals, gaskets, hose permeation and even small failures in 

the containment of the refrigerant, or more quickly through rapid component deterioration, 

vehicle accidents or during maintenance and end of-life vehicle scrappage (especially when 

refrigerant capture and recycling programs are less efficient). The leakage emissions can be 

reduced through the choice of leak-tight, durable components, or the global warming impact 

of leakage emissions can be addressed by using an alternative refrigerant with lower GWP. 

These options are described more fully in DRIA Chapter 2. 

EPA’s analysis indicates that together, these A/C- related emissions account for 

approximately 8% of the GHG emissions from cars and light trucks. EPA is proposing credit 

provisions which we expect all manufacturers to utilize which are expected to reduce direct 

leakage emissions by 50% and to reduce the incremental increase of A/C related CO2 

emissions by 40% in model year 2016 vehicles, with a gradual phase-in starting in model year 

2012. It is appropriate to separate the discussion of these two categories of A/C-related 

emissions because of the fundamental differences in the emission mechanisms and the 

methods of emission control. Refrigerant leakage control is akin in many respects to past EPA 

fuel evaporation control programs in that containment of a fluid is the key control feature, 

while efficiency improvements are more similar to the vehicle-based control of CO2 in that 

they would be achieved through specific hardware and controls. 

The anticipated phase-in of air conditioning controls is shown in Table 5-16. The 

market penetration is based upon analysis from the OMEGA model. OMEGA projections 

show improved A/C technology market penetration at 85% of the market in 2016. This 85% 

cap is then roughly linearized across the five year period (Table 5-16). Because HFC leakage 

is somewhat independent of vehicle miles traveled, HFC reduction % is based on the 

proportion of new vehicles that have HFC leakage containment technology. By contrast, 

indirect A/C reduction % is dependent upon the travel fraction, and is proportional to the 

VMT attributable to vehicles with the control technology. 

Table 5-16 – AC Control by Model Year (Reduction from Base Emissions) 

 MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

MY 

2016+ 

Market Penetration of technology 25% 40% 55% 75% 85%

HFC Reduction % -13% -21% -28% -38% -43%

Indirect Reduction % -10% -16% -22% -30% -34%

The penetrations of A/C control technology and HFC reductions shown in this section 

differ slightly from those shown in DRIA chapter 2, and in Preamble section III. The HFC 

credits discussed in this section are slightly larger (9%) than the proposed program credits, 

while the penetration schedule of the credits is slightly lower. The net effect is a less than 1% 
Draft Regulatory Impact Analysis 

5-20 

overstatement of total program GHG related benefits. EPA will address this issue in the final 

rulemaking. 

5.3.3.2.1 Direct A/C (HFC) Emissions 

The projected HFC baseline inventories are derived from previous EPA analyses.29 

HFC emissions are a leakage type emission, similar to other evaporative emissions 

from a vehicle.30 Consequently, HFC emissions are tied more closely to vehicle stock than to 

VMT. 

To calculate HFC emissions, the per-vehicle per-year emission contribution of the 

current vehicle fleet was determined using averaged 2005 and 2006 registration data from the 

Transportation Energy Databook (TEDB)31 and 2005 and 2006 mobile HFC leakage estimates 

from the EPA Emissions and Sinks report. This per-vehicle per-year contribution was then 

scaled to the projected vehicle fleet in each future year using data from the emission modeling 

analysis. This analysis assumes that the leakage rates of the current fleet remain constant into 

the future. Preliminary EPA estimates suggest that air conditioner charge size is decreasing, 

which implies that the current analysis may somewhat overstate the HFC emission inventory. 

The resulting HFC inventory is a combination top-down/bottom up inventory and 

includes leakage, maintenance/servicing, and disposal/end of life phases of HFC. The 

proposed EPA program is expected to impact only two of these phases of the HFC inventory 

by reducing leakage and reducing need for servicing. 

The vehicle population model from the emission analysis was used to calculate the 

penetration of the technology into the market by calendar year. The equation used for 

calculating the reductions in HFC is shown below (Equation 6). 

Emissions Reductions = Reduction % by Calendar Year x Total CY inventory 

Reduction % by CY = ∑Calendar Year (Reduction % by MY x Vehicle Population by MY)/Total Vehicle Population 

Equation 6 - HFC Inventory Calculation 

Table 5-17 shows the calculated penetration of technology into the vehicle fleet and 

consequent reduction from baseline HFC Inventory. 

Table 5-17 - HFC (Direct A/C) Emissions 

Calendar 

Year 

Baseline HFC 

(MMT CO2EQ) 

Penetration of 

Technology 

(Population 

Based) 

Reduction From 

Baseline 

(%) 

Reduction from 

Baseline 

(MMT CO2EQ) 

2010 55.0 0% 0% 0.0 

2020 61.5 43% -21% -13.5 

2030 70.5 76% -38% -27.2 

2040 76.4 84% -42% -32.1 

2050 82.1 85% -42% -34.9 
Emissions Impacts 

5-21 

5.3.3.2.2 Indirect A/C (CO2) Emissions 

By adding an additional load to the powertrain, A/C indirectly causes an increase in 

tailpipe CO2 emissions. Thus, where HFC inventory is proportional to penetration of the 

technology into the vehicle population, the indirect A/C emission inventory is proportional to 

VMT of those vehicles. Because newer vehicles are assumed to be driven more, indirect A/C 

control technology benefits the fleet more quickly than HFC control technology. 

The emission rates for indirect A/C usage were taken from the EPA analysis 

documented in DRIA chapter 2. There, indirect A/C usage is calculated to add 14.25 grams 

of CO2 emissions to the certification emissions of either cars or trucks. The indirect A/C 

controls proposed in the rule are estimated to remove up to 40% of the emission impact of air 

conditioning systems, or 5.7 grams per mile. 

 The OMEGA post processor was used to calculate the contribution the indirect A/C 

program to the overall inventory. Reference and Control scenario emissions due to anticipated 

improvements to indirect A/C systems are shown in Table 5-18. 

Table 5-18 –Indirect A/C Emissions 

Calendar 

Year 

Baseline Indirect A/C 

(MMT CO2EQ) 

Reduction From 

Baseline 

(%) 

Reduction from 

Baseline 

(MMT CO2EQ) 

2010 52.9 -0% 0 

2020 55.2 -20% -11.0 

2030 65.9 -32% -21.1 

2040 80.6 -34% -27.2 

2050 100.5 -34% -34.1 

It should be noted that the baseline indirect A/C emissions are included within the onroad adjustment factor. The baseline inventory is not double counted when aggregating the 

components of this program. 

5.3.3.3 Tailpipe Co-pollutant Emissions 

Due to the rebound effect, the downstream emissions of several co-pollutants are 

anticipated to increase. These inventories are calculated in a similar manner to the CO2

emissions. Rebound VMT, which is the additional driving, is broken into distribution by 

vehicle age. VMT by each age was then multiplied by the appropriate emission factor. These 

emissions by age were then summed by calendar year (Equation 7,Table 5-19). 

The EPA reference fleet assumes a small number of diesel vehicles are sold in each 

year (~20 thousand out of ~13-16 million). For the criteria emission analysis, it was assumed 

that 0.5% of new light duty vehicles sold were diesels. Because diesel fueled vehicles are 
Draft Regulatory Impact Analysis 

5-22 

subject to the same Tier 2 emission standards as gasoline fueled vehicles, the emission rates 

of criteria pollutants are similar.E

EmissionsCalendar Year = ∑Calendar Year (Rebound VMT by Age * Emission Factor by Age ) 

Equation 7 - Emissions by Calendar Year 

Table 5-19 - Delta GHG Emissions Due to Rebound (Metric Tons) 

 CALENDAR YEAR 

 2020 2030 2040 2050 

Gasoline Fueled Vehicles

Δ CH4 307 644 857 1079

Δ N2O 134 284 377 3475

Diesel Fueled Vehicles 

Δ CH4 0.13 0.25 0.32 0.40

Δ N2O 0.20 0.40 0.52 0.66

 E

 Emissions rates between tier 2 gasoline and diesel vehicles are similar but not identical due to the particulars of 

operations of the engine types. Diesel and gasoline engines emit differently during start, as well as during the 

various modes of operation. 
Emissions Impacts 

5-23 

Table 5-20 - Delta Downstream non-GHG Emissions (Short Tons) 

 CALENDAR YEAR 

 2020 2030 

Gasoline Fueled Vehicles

Δ 1,3-Butadiene 13.08 39.75 

Δ Acetaldehyde 24.58 74.86 

Δ Acrolein 1.22 3.72 

Δ Benzene 79.27 241.26 

Δ CO 77,648.80 241,314.67 

Δ Formaldehyde 31.08 94.43

Δ NOx 5,128.09 15,110.31 

Δ PM 2.5 217.31 569.82 

Δ SO2 -2,502.6 -4,905.6

Δ VOC 1,678.90 5,442.80 

Diesel Fueled Vehicles 

Δ 1,3-Butadiene 0.17 0.44 

Δ Acetaldehyde 0.23 0.60 

Δ Acrolein 0.07 0.17 

Δ Benzene 0.37 0.98 

Δ CO 174.13 624.39 

Δ Formaldehyde 0.72 1.89

Δ NOx 225.72 449.95

Δ PM 2.5 0.88 1.87

Δ SO2 Attributed to Gasoline 

Δ VOC 19.33 51.03

In general, downstream emissions are predicted to increase a small amount due to 

rebound driving. The one exception is sulfur emissions (SO2), which are predicted to 

decrease as a result of the decrease in fuel consumption. As shown in section 5.3.4, the 

increases in non-ghg pollutants are generally less than the projected decreases on the upstream 

side. The exceptions are in those pollutants, such as carbon monoxide (CO), where a 

relatively small of US emissions comes from upstream sources. 

5.3.3.4 Fuel Savings 

The proposed EPA program is anticipated to create significant fuel savings as 

compared to the reference case. Projected fuel savings are shown in Table 5-21. Fuel savings 

can be calculated from total tailpipe CO2 avoided (including CO2 due to driving and indirect 
Draft Regulatory Impact Analysis 

5-24 

A/C use) using a conversion factor of 8887 grams of CO2 per gallon of gasoline. All fuel 

saved is considered 100% gasoline without any oxygenate.F,32

Fuel savings were calculated from total tailpipe CO2 avoided (including CO2 due to 

driving and indirect A/C) using a conversion factor of 8887 grams of CO2 per gallon of 

gasoline. 33

Table 5-21 - Downstream Fuel Consumption Changes by Calendar Year 

(Billions of Gallons of Gasoline Equivalent) 

2020 2030 2040 2050

Fuel Consumption (Reference) 142.2 161.9 196.2 244.1

Δ Total Fuel Consumption due 

to EPA Program -13.4 -26.2 -33.9 -42.6

Δ Fuel Consumption due to 

10% rebound 1.2 2.3 3.0 3.8 

Δ Fuel Consumption due to 

A/C controls -1.2 -2.4 -3.1 -3.8 

5.3.4 Calculation of Upstream Emissions 

The term "upstream emissions" refers to air pollutant emissions generated from all 

crude oil extraction, transport, refining, and finished fuel transport, storage, and distribution. 

As shown above in Table 5-4 this includes all the stages prior to the final filling of vehicle 

fuel tanks at retail service stations. The details of the assumptions, data sources, and 

calculations that were used to estimate the emission impacts presented here can be found in 

the Technical Support Document and the docket memo, "Calculation of Upstream Emissions 

for the GHG Vehicle Rule."34

5.4 Greenhouse Gas Emission Inventory 

This section presents total program calendar year impacts by sector (Table 5-22, Table 

5-23,Table 5-24). Upstream, downstream, and total program impact are presented. 

 F

 Based on the documentation of the on-road gap, it would be justifiable to assume an ethanol percentage of 

0.8%. This volume of ethanol would result in a total energy difference of less than 0.5%. See the fuel labeling 

rule technical support document, EPA420-R-06-017, for further details. 
Emissions Impacts 

5-25 

Table 5-22 – Downstream GHG and Fuel Consumption Changes vs. Reference Case 

2020 2030 2040 2050 

Δ CO2 (Metric Tons) -118,682,739 -232,643,716 -301,498,777 -378,287,357 

Δ CH4 (Metric tons) 308 645 857 1,080 

Δ N2O (Metric tons) 134 284 378 476 

Δ HFC (Metric tons) -9,429 -18,987 -22,420 -24,407 

Δ GHG (MMT CO2 EQ) -132.1 -259.7 -333.4 -413.0 

Δ Fuel Consumption (billion 

gallons per year) 

-13.4 -26.2 -33.9 -42.6 

Table 5-23 – Upstream GHG Change vs. Reference Case 

2020 2030 2040 2050 

Δ CO2 (Metric Tons) -28,857,236 -56,566,395 -73,308,230 -91,979,068 

Δ CH4 (Metric tons) -163,638 -320,765 -415,701 -521,576 

Δ N2O (Metric tons) -464 -909 -1,178 -1,478 

Δ GHG (MMT CO2 EQ) -33.1 -64.9 -84.1 -105.5 

Table 5-24 – Total GHG and Fuel Consumption Changes vs. Reference Case 

2020 2030 2040 2050 

Δ CO2 (Metric Tons) -147,539,975 -289,210,111 -374,807,007 -470,266,424 

Δ CH4 (Metric tons) -163,330 -320,120 -414,844 -520,496 

Δ N2O (Metric tons) -329 -625 -800 -1,002 

Δ HFC (Metric tons) -9,429 -18,987 -22,420 -24,407 

Δ GHG (MMT CO2 EQ) -165.2 -324.6 -417.5 -518.5 

Δ Fuel Consumption 

(billion gallons per year) 

-13.4 -26.2 -33.9 -42.6 

5.4.1 Impact on US and Global GHG Inventory 

As stated in the introduction, climate change is widely viewed as the most significant 

long-term threat to the global environment. According to the Intergovernmental Panel on 

Climate Change, anthropogenic emissions of greenhouse gases are very likely (90 to 99 

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

All mobile sources emitted 31.5 percent of all US GHG in 2006, and have been the fastest -

growing source of US GHG since 1990. Light-duty vehicles are responsible for nearly 60 

percent of all mobile source GHGs. For light-duty vehicles, CO2 emissions represent about 

95 percent of all greenhouse emissions, and the CO2 emissions measured over the EPA tests 
Draft Regulatory Impact Analysis 

5-26 

used for fuel economy compliance represent over 90 percent of total light-duty vehicle 

greenhouse gas emissions. 

This action is an important step towards curbing steady growth of GHG emissions 

from cars and light trucks. In the absence of control, GHG emissions worldwide and in the 

U.S. are projected to continue steady growth; U.S. GHGs are estimated to make up roughly 15 

percent of total worldwide emissions, and the contribution of direct emissions from cars and 

light-trucks to this U.S. share is growing over time, reaching an estimated 20 percent of U.S. 

emissions by 2030 in the absence of control. 

As discussed elsewhere in this proposal, this steady rise in GHG emissions is 

associated with numerous adverse impacts on human health, food and agriculture, air quality, 

and water and forestry resources. 

5.5 Non-Greenhouse Gas Emission Inventory 

The reference case emission inventories used for this proposed rule are obtained from 

different sources depending on sector. 

 For stationary/area sources and aircraft, 2020 projections were used from the 2002 

National Emissions Inventory (NEI), Version 3. The development of these inventories is 

documented in the November 27, 2007, memo titled, "Approach for Developing 2002 and 

Future Year National Emission Summaries," from Madeleine Strum to Docket EPA-HQOAR-2007-0491. That memo summarizes the methodologies and additional reference 

documents for criteria air pollutants (CAP) and mobile source air toxics (MSATs). The 

effects of the Clean Air Interstate rule are not included here. 

For onroad mobile sources, the MOVES Draft 2009 model was used that estimates 

emissions from light-duty and heavy-duty gasoline and diesel vehicles, except for 

motorcycles. For motorcycles, the MOBILE6.2 model was used as run using the NMIM 

platform that applies county specific fuel properties and temperatures. For the MOVES 

model runs the Vehicle Miles Traveled (VMT) of light-duty gasoline vehicles was adjusted to 

account for factors related to this proposal, such as the ten percent rebound effect as described 

above in Sections 5.3.3.1.1 and 5.3.3.1.2. 

Most nonroad equipment was modeled with NONROAD2005d using NMIM, which is 

a version of the NONROAD that includes the benefits of the two nonroad regulations 

published in 2008 (the locomotive and marine diesel rule and the small spark-ignition and 

recreational marine engine rule).35, 36 

Inventories for locomotives and commercial marine vessels are not covered by the 

NONROAD model, and they have been updated since the 2002 NEI and its future year 

projections were completed. Thus the more recent inventory projections published in the 

regulatory impact analyses of their respective recent rulemakings were used.35, 37 

Locomotives and C1/C2 commercial marine vessel inventories come from the spring 2008 
Emissions Impacts 

5-27 

final rule, and the C3 commercial marine emission inventory is from the base case inventories 

in the June 2009 proposed rule. 

Table 5-25 and Table 5-26 show the total 2020 and 2030 mobile and non-mobile 

source inventory projections that were used as the reference case against which impacts of the 

rule were applied. The impacts, expressed as percentages, are presented below in Sections 

5.5.1 through 5.5.3. 

Table 5-25. 2020 Reference Case Emissions by Sector (annual short tons) 

VOC CO NOX PM10 PM2.5 SO2 

Onroad Gasoline 1,973,180 29,211,716 1,934,488 96,380 58,990 30,922 

Onroad Diesel 129,321 260,238 1,353,773 32,733 40,071 4,218 

Nonroad SIa 1,289,918 14,286,250 242,828 53,092 49,019 15,413 

Other Nonroadb 234,870 1,424,643 3,389,761 230,553 210,509 943,226 

Stationary/Area 8,740,057 11,049,239 5,773,927 3,194,610 3,047,714 7,864,681 

Total 12,367,346 56,232,087 12,694,778 3,607,368 3,406,303 8,858,459 

TABLE 5-25 

CONTINUED 

BENZENE 1,3-

BUTADIENE

ACETALDEHYDE FORMALDEHYDE ACROLEIN 

Onroad Gasoline 60,742 7,518 14,604 18,716 903 

Onroad Diesel 1,571 830 3,743 10,010 475 

Nonroad SIa 36,862 5,895 4,768 10,240 584 

Other Nonroadb 3,760 929 9,542 22,324 1,013 

Stationary/Area 111,337 1,847 13,118 23,846 3,412 

Total 214,273 17,019 45,777 85,136 6,387 

a

 Nonroad gasoline, LPG, and CNG engines plus portable fuel containers 

b

 Nonroad diesel engines and all locomotive, aircraft, and commercial marine 
Draft Regulatory Impact Analysis 

5-28 

Table 5-26. 2030 Reference Case Emissions by Sector (annual short tons) 

VOC CO NOX PM10 PM2.5 SO2 

Onroad Gasoline 1,800,856 32,038,635 1,504,390 110,796 67,416 36,011 

Onroad Diesel 140,959 219,594 1,120,656 34,746 26,498 5,478 

Nonroad SIa 1,198,679 15,815,805 243,515 55,011 50,816 17,270 

Other Nonroadb

238,652 1,411,393 3,427,832 253,572 229,183 1,426,994 

Stationary/Area 8,740,057 11,049,239 5,773,927 3,194,610 3,047,714 7,864,681 

Total 12,119,203 60,534,666 12,070,321 3,648,735 3,421,628 9,350,433 

Table 5-26 

continued Benzene 1,3-

Butadiene

Acetaldehyde Formaldehyde Acrolein

Onroad Gasoline 55,692 6,840 13,354 17,071 812

Onroad Diesel 1,706 915 4,050 10,903 517

Nonroad SIa 39,871 6,279 5,118 11,229 629

Other Nonroadb 3,764 979 9,579 22,487 1,055

Stationary/Area 111,337 1,847 13,118 23,846 3,412

Total 212,371 16,859 45,220 85,536 6,425

a

 Nonroad gasoline, LPG, and CNG engines plus portable fuel containers 

b

 Nonroad diesel engines and all locomotive, aircraft, and commercial marine 

5.5.1 Downstream Impacts of Program 

As described in the introduction, downstream inventories were generated using 

algorithms from EPA’s Optimization Model for reducing Emissions of Greenhouse gases 

from Automobiles (OMEGA). The OMEGA benefits post-processor produces a national 

scale analysis of the benefits (emission reductions, monetized co-benefits) of the analyzed 

program. The non-GHG emission results shown here (Table 5-27) were calculated in a 

spreadsheet analysis using algorithms from the Draft MOVES 2009 emission database and 

algorithms from the OMEGA post-processor. 
Emissions Impacts 

5-29 

Table 5-27. Downstream Emission Changes of Proposed Program 

CALENDAR YEAR 

2020 

CALENDAR YEAR 

2030 

POLLUTANT 

Short Tons

Percent 

Change in 

US Total 

Short Tons 

Percent 

Change in 

US Total 

Δ 1,3-Butadiene 13.2 0.078% 40.2 0.238% 

Δ Acetaldehyde 25 0.054% 75 0.167% 

Δ Acrolein 1.29 0.020% 3.89 0.061% 

Δ Benzene 80 0.037% 242 0.114% 

Δ Carbon Monoxide 77,823 0.138% 241,939 0.400% 

Δ Formaldehyde 32 0.037% 96 0.113% 

Δ Oxides of Nitrogen 5,354 0.042% 15,560 0.129% 

Δ Particulate Matter 

(below 2.5 micrometers) 

218 0.006% 572 0.017% 

Δ Oxides of Sulfur -2,503 -0.028% -4,906 -0.052% 

Δ Volatile Organic Compounds 1,698 0.014% 5,494 0.045% 

5.5.2 Upstream Impacts of Program 

Fuel production and distribution emission impacts of the proposed program were 

estimated in conjunction with the development of life cycle GHG emission impacts, and the 

GHG emission inventories discussed above. The basic calculation is a function of fuel 

volumes in the analysis year and the emission factors associated with each process or 

subprocess. 

In general this life cycle analysis uses the same methodology as the Renewable Fuel 

Standard (RFS2) proposed rule. It relies partially on the “Greenhouse Gases, Regulated 

Emissions, and Energy Use in Transportation” (GREET) model, developed by the Department 

of Energy’s Argonne National Laboratory (ANL), but takes advantage of additional 

information and models to significantly strengthen and expand on the GREET analysis. 

Updates and enhancements to the GREET model assumptions include updated crude 

oil and gasoline transport emission factors that account for recent EPA emission standards and 

modeling, such as the Tier 4 diesel truck standards published in 2001 and the locomotive and 

commercial marine standards finalized in 2008. In addition, GREET does not include air 

toxics. Thus emission factors for the following air toxics were added: benzene, 1,3-

butadiene, formaldehyde, acetaldehyde, and acrolein. These upstream toxics emission factors 

were calculated from the 2002 National Emissions Inventory (NEI), a risk and technology 

review for petroleum refineries, speciated emission profiles in EPA's SPECIATE database, or 
Draft Regulatory Impact Analysis 

5-30 

the Mobile Source Air Toxics rule (MSAT) inventory for benzene; these pollutant tons were 

divided by refinery energy use or gasoline distribution quantities published by the DOE 

Energy Information Administration (EIA) to get emission factors in terms of grams per 

million BTU of finished gasoline. The resulting emission factors are presented in Chapter 4 

of the draft joint TSD for today's proposed rule. 

Results of these emission inventory impact calculations relative to the reference case 

for 2020 and 2030 are shown in Table 5-28 for the criteria pollutants and individual air toxic 

pollutants. 

The proposed program is projected to provide reductions in all pollutants associated 

with gasoline production and distribution as the projected fuel savings reduce the quantity of 

gasoline needed. 

Table 5-28. Upstream Emission Changes of Proposed Program 

CALENDAR YEAR 

2020 

CALENDAR YEAR 

2030 

POLLUTANT 

Short Tons

Percent 

Change in 

US Total 

Short 

Tons 

Percent 

Change in 

US Total 

Δ 1,3-Butadiene -1.8 -0.010% -3.4 -0.020% 

Δ Acetaldehyde -8 -0.017% -15 -0.033% 

Δ Acrolein -1 -0.017% -2 -0.032% 

Δ Benzene -163 -0.076% -320 -0.151% 

Δ Carbon Monoxide -7,209 -0.013% -14,107 -0.023% 

Δ Formaldehyde -60 -0.071% -112 -0.131% 

Δ Oxides of Nitrogen -22,560 -0.178% -43,286 -0.359% 

Δ Particulate Matter 

(below 2.5 micrometers) -3,075 -0.090% -6,003 -0.175% 

Δ Oxides of Sulfur -13,804 -0.156% -27,060 -0.289% 

Δ Volatile Organic Compounds -75,437 -0.610% -147,841 -1.220% 

5.5.3 Total Program Impact 

Table 5-29 shows the combined impacts of downstream and upstream aspects of the 

proposed program. The fuel production and distribution impacts of the proposed program on 

VOC, NOx, PM2.5, and SOx are mainly due to reductions in emissions associated with 

gasoline production and distribution as the projected fuel savings of the program reduce the 

quantity of gasoline needed. Increases in CO are driven by the rebound effect on VMT, 

which are only partially offset by upstream reductions. 

Air toxic emission impacts depend on the relative reductions from upstream emissions 
Emissions Impacts 

5-31 

versus increases due to rebound on the downstream emissions. Relative to 2030 US total 

reference case emissions, formaldehyde and benzene emissions are projected to decrease by 

0.02 to 0.04 percent, but 1,3-butadiene, acetaldehyde, and acrolein emissions would increase 

by 0.03 to 0.22 percent. 

Table 5-29. Total Non-GHG Emission Changes of Proposed Program 

CALENDAR YEAR 

2020 

CALENDAR YEAR 

2030 

POLLUTANT 

Short Tons

Percent 

Change in 

US Total 

Short 

Tons 

Percent 

Change in 

US Total 

Δ 1,3-Butadiene 11.5 0.07% 36.8 0.22% 

Δ Acetaldehyde 17 0.04% 61 0.13% 

Δ Acrolein 0.2 0.00% 1.8 0.03% 

Δ Benzene -84 -0.04% -77 -0.04% 

Δ Carbon Monoxide 70,614 0.13% 227,832 0.38% 

Δ Formaldehyde -28 -0.03% -16 -0.02% 

Δ Oxides of Nitrogen -17,206 -0.14% -27,726 -0.23% 

Δ Particulate Matter 

(below 2.5 micrometers) -2,856 -0.08% -5,431 -0.16% 

Δ Oxides of Sulfur -16,307 -0.18% -31,965 -0.34% 

Δ Volatile Organic Compounds -73,739 -0.60% -142,347 -1.17% 

5.6 Model Year Lifetime Analyses 

5.6.1 Methodology 

EPA also conducted a separate analysis of the total benefits over the model year 

lifetime of 2012 through 2016 model year vehicles. In contrast to the calendar year analysis, 

the model year lifetime analysis shows the lifetime impacts of the program on each MY fleet 

over the course of its existence. 

In this analysis, a simplified VMT schedule is used. Rather than using a MY specific 

VMT schedule for each MY, a single VMT schedule is used for all five model years. This 

VMT schedule is more fully described in the draft joint TSD. In brief, it was derived using 

the same methodology as the MY-specific VMT schedules and is the average of the VMT 

schedules from 2012-2030 (Table 5-30). 

All other inputs, including sales, emission factors and achieved emission levels are the 

same between the two analyses. 
Draft Regulatory Impact Analysis 

5-32 

 

Table 5-30 - Updated Survival Fraction and Mileage Accumulation by Age 

AGE PA 

SURVIVAL 

FRACTION 

PA 

MILEAGE 

NPA 

SURVIVAL 

FRACTION 

NPA 

MILEAGE 

0 0.9950 16,932 0.9950 18,847 

1 0.9900 16,603 0.9741 18,408 

2 0.9831 16,257 0.9603 18,050 

3 0.9731 15,814 0.9420 17,575 

4 0.9593 15,414 0.9190 17,142 

5 0.9413 14,993 0.8913 16,593 

6 0.9188 14,545 0.8590 16,095 

7 0.8918 14,105 0.8226 15,493 

8 0.8604 13,624 0.7827 14,891 

9 0.8252 13,192 0.7401 14,336 

10 0.7866 12,668 0.6956 13,689 

11 0.7170 12,222 0.6501 13,160 

12 0.6125 11,705 0.6042 12,554 

13 0.5094 11,191 0.5517 11,945 

14 0.4142 10,727 0.5009 11,342 

15 0.3308 10,283 0.4522 10,822 

16 0.2604 9,878 0.4062 10,383 

17 0.2028 9,482 0.3633 9,900 

18 0.1565 9,090 0.3236 9,433 

19 0.1200 8,691 0.2873 9,033 

20 0.0916 8,366 0.2542 8,692 

21 0.0696 8,126 0.2244 8,499 

22 0.0527 8,003 0.1975 8,246 

23 0.0399 7,774 0.1735 8,261 

24 0.0301 7,587 0.1522 8,066 

25 0.0227 7,424 0.1332 8,066 

26 0.0000 7,334 0.1165 8,101 

27 0.0000 7,200 0.1017 8,098 

28 0.0000 7,103 0.0887 8,096 

29 0.0000 7,044 0.0773 8,095 

30 0.0000 7,042 0.0673 8,093 

31 0.0000 7,039 0.0586 8,092 

32 0.0000 7,033 0.0509 8,086 

33 0.0000 7,021 0.0443 8,080 

34 0.0000 7,007 0.0385 8,064 

35 0.0000 6,988 0.0334 8,050 
Emissions Impacts 

5-33 

5.6.2 Results 

The GHG emission reductions are shown for each model year, as are the co-pollutant 

impacts (Table 5-31, Table 5-32). 

Table 5-31 – Lifetime GHG Emissions vs. Reference Case (MMT CO2 EQ) 

MY 2012 MY 2013 MY 

2014 

MY 

2015 

MY 

2016 

Program 

Total 

Δ Downstream Tailpipe 

Emission -53.19 -79.99 -110.75 -154.99 -213.28 -612.19

Δ Downstream Indirect 

A/C -5.33 -9.04 -12.88 -17.87 -20.28 -65.39

Δ Downstream 

Direct A/C -6.92 -11.73 -16.72 -23.20 -26.32 -84.89

Δ Downstream CH4 0.00 0.01 0.01 0.01 0.02 0.05

Δ Downstream N2O 0.02 0.03 0.05 0.06 0.10 0.26

Total Δ Downstream -65.41 -100.71 -140.29 -195.99 -259.76 -762.17

 

Δ Upstream CO2 -14.23 -21.65 -30.06 -42.03 -56.79 -164.75

Δ Upstream CH4 -1.69 -2.58 -3.58 -5.01 -6.76 -19.62

ΔUpstream N2O -0.07 -0.11 -0.15 -0.21 -0.28 -0.82

Total Δ Upstream -15.99 -24.33 -33.79 -47.25 -63.83 -185.19

 

Total Program Δ GHG 

Emissions -81.41 -125.05 -174.08 -243.23 -323.59 -947.36

 

Total Program Fuel 

Savings (Billion 

Barrels) 0.16 0.24 0.33 0.46 0.63 1.82 
Draft Regulatory Impact Analysis 

5-34 

Table 5-32 – Lifetime non-GHG Emissions vs. Reference Case (Short Tons) 

MY 2012 MY 2013 MY 2014 MY 2015 MY 2016 Program 

Total 

Downstream 

Δ VOC 1,495 2,373 3,336 4,751 6,763 18,717

Δ NOX 3,991 6,602 9,469 13,485 20,082 53,629

Δ PM 2.5 152 241 338 482 686.074 1,899

Δ CO 63,783 102,779 145,598 207,338 295,494 814,992

Δ SO2 -1,234 -1,877 -2,607 -3,645 -4,925 -14,288

Δ Benzene 65.1 103.4 145.4 207.1 294.2 815

Δ 1,3 Butdiene 10.8 17.1 24.1 34.3 48.8 135

Δ Formaldehyde 25.9 41.1 57.9 82.4 117.1 324

Δ Acetaldehyde 20.3 32.2 45.3 64.5 91.6 254

Δ Acrolein 1.0 1.7 2.3 3.3 4.7 13

 

Upstream 

Δ VOC -37,188 -56,572 -78,562 -109,850 -148,418 -430,591

Δ NOX -10,888 -16,564 -23,002 -32,163 -43,455 -126,072

Δ PM 2.5 -1,510 -2,297 -3,190 -4,460 -6,026 -17,484

Δ CO -3,549 -5,398 -7,496 -10,482 -14,162 -41,087

Δ SO2 -6,807 -10,354 -14,379 -20,106 -27,165 -78,812

Δ Benzene -80.4 -122.3 -169.9 -237.6 -321.0 -931

Δ 1,3 Butdiene -0.9 -1.3 -1.8 -2.6 -3.5 -10

Δ Formaldehyde -28.2 -42.9 -59.5 -83.2 -112.5 -326

Δ Acetaldehyde -3.7 -5.7 -7.9 -11.0 -14.9 -43

Δ Acrolein -0.5 -0.8 -1.1 -1.5 -2.1 -6

 

Total 

Δ VOC -35,694 -54,199 -75,226 -105,099 -141,655 -411,874

Δ NOX -6,897 -9,962 -13,533 -18,678 -23,373 -72,443

Δ PM 2.5 -1,358 -2,056 -2,852 -3,978 -5,340 -15,585

Δ CO 60,234 97,381 138,101 196,856 281,332 773,905

Δ SO2 -8,041 -12,232 -16,986 -23,751 -32,090 -93,099

Δ Benzene -15 -19 -24 -30 -27 -116

Δ 1,3 Butdiene 10 16 22 32 45 125

Δ Formaldehyde -2 -2 -2 -1 5 -2

Δ Acetaldehyde 17 27 37 53 77 211

Δ Acrolein 1 1 1 2 3 7

5.7 Alternative 4% and 6% Scenarios 

For this proposal, two alternative control scenarios were evaluated characterized by 

4% and 6% annual growth in the GHG standards from the MY 2011 standard. Other than the 
Emissions Impacts 

5-35 

standards, these scenarios share all inputs with the proposed EPA program. Only GHG 

reductions and fuel savings are shown for these programs. 

5.7.1 4% Scenario 

5.7.1.1 Standards and Achieved Levels 

The program standards are shown in Table 5-33 and the achieved levels are shown in Table 

5-34. 

Table 5-33: 4% Scenario Standards 

MODEL 

YEAR 

PA 

EMISSION 

LEVEL 

NPA EMISSION 

LEVEL 

ANTICIPATED 

MY EMISSION 

LEVEL 

2012 276 366 310 

2013 265 355 298 

2014 255 342 286 

2015 246 331 275 

2016 237 318 264 

Table 5-34: 4% Scenario Achieved Levels 

MODEL 

YEAR 

ANTICIPATED 

PA EMISSION 

LEVEL 

ANTICIPATED 

NPA EMISSION 

LEVEL 

ANTICIPATED 

MY EMISSION 

LEVEL 

2012 275 378 314 

2013 266 368 304 

2014 258 352 292 

2015 249 338 279 

2016 237 319 264 

5.7.1.2 Results 

Results are shown relative to the same reference scenario as the proposed EPA 

program. Both calendar year and model year lifetime results are shown. 
Draft Regulatory Impact Analysis 

5-36 

Table 5-35 – Downstream CY GHG Reductions and Fuel Savings vs. Reference Case 

CY 

2020 

CY 

2030 

CY 

2040 

CY 

2050 

Downstream 

Δ CO2 excluding indirect A/C controls (MMT CO2 EQ) -97.7 -196.6 -255.5 -320.7 

ΔIndirect A/C CO2(MMT CO2 EQ) -11.0 -21.1 -27.2 -34.1 

Δ Direct A/C HFC (MMT CO2 EQ) -13.5 -27.2 -32.1 -34.9 

Δ CH4 (MMT CO2 EQ) 0 0 0 0 

Δ N2O (MMT CO2 EQ) 0 0 0.1 0.1 

Δ Total GHG (MMT CO2 EQ) -122.2 -244.8 -314.7 -389.6 

 

Upstream 

Δ CO2 (MMT CO2 EQ) -26.4 -52.9 -68.7 -86.2 

Δ CH4 (MMT CO2 EQ) -4.1 -8.0 -10.4 -13.0 

Δ N2O (MMT CO2 EQ) -0.1 -0.3 -0.3 -0.4 

Δ Total GHG -30.5 -61.2 -79.4 -99.6 

Total 

Δ Total GHG -152.7 -306.0 -394.4 -489.2 

Δ Fuel Consumption (Annual, Billion gallons) -12.2 -24.5 -31.8 -39.9 
Emissions Impacts 

5-37 

Table 5-36 – Total Model Year Lifetime GHG Reductions vs. Baseline 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

MY 

2016 

Program 

Total 

Downstream 

Δ CO2 excluding indirect A/C controls 

(MMT CO2 EQ) -22.1 -55.2 -100.3 -145.4 -198.8 -521.8 

ΔIndirect A/C CO2(MMT CO2 EQ) -5.3 -9.0 -12.9 -17.9 -20.3 -65.4 

Δ Direct A/C HFC (MMT CO2 EQ) -6.9 -11.7 -16.7 -23.2 -26.3 -84.9 

Δ CH4 (MMT CO2 EQ) 0.0 0.0 0.0 0.0 0.0 0.0 

Δ N2O (MMT CO2 EQ) 0.0 0.0 0.0 0.1 0.1 0.2 

Δ Total GHG (MMT CO2 EQ) -34.3 -75.9 -129.9 -186.4 -245.3 -671.8 

 

Upstream 

Δ CO2 (MMT CO2 EQ) -6.7 -15.6 -27.5 -39.7 -53.3 -142.8 

Δ CH4 (MMT CO2 EQ) -0.8 -1.9 -3.3 -4.7 -6.3 -17.0 

Δ N2O (MMT CO2 EQ) 0.0 -0.1 -0.1 -0.2 -0.3 -0.7 

Δ Total GHG -7.5 -17.6 -30.9 -44.6 -59.9 -160.5 

 

Total 

Δ Total GHG -41.8 -93.5 -160.8 -231.0 -305.2 -832.3 

Δ Fuel Consumption (Annual, Billion 

gallons) 

 

-3.09 -7.3 -12.7 -18.4 -24.7 

 

-66.1 

5.7.2 6% Scenario 

5.7.2.1 Standards and Achieved Levels 

The program standards are shown in Table 5-33 and the achieved levels are shown in 

Table 5-34. 

Table 5-37: 6% Scenario Standards 

MODEL 

YEAR 

ANTICIPATED 

PA EMISSION 

LEVEL 

ANTICIPATED 

NPA EMISSION 

LEVEL 

ANTICIPATED 

MY EMISSION 

LEVEL 

2012 269 362 304 

2013 255 342 287 

2014 241 323 270 

2015 228 306 255 

2016 216 290 241 
Draft Regulatory Impact Analysis 

5-38 

Table 5-38: 6% Scenario Achieved Levels 

MODEL 

YEAR 

ANTICIPATED 

PA EMISSION 

LEVEL 

ANTICIPATED 

NPA EMISSION 

LEVEL 

ANTICIPATED 

MY EMISSION 

LEVEL 

2012 270 375 309 

2013 258 352 292 

2014 244 332 275 

2015 230 313 259 

2016 216 290 241 

5.7.2.2 Results 

Results are shown relative to the same reference scenario as the proposed EPA 

program. Both calendar year and model year lifetime results are shown. 

Table 5-39 –CY GHG Emissions and Fuel Consumption vs. Reference Case 

CY 

2020 

CY 

2030 

CY 

2040 

CY 

2050 

Downstream 

Δ CO2 excluding indirect A/C controls (MMT CO2 EQ) -146.8 -290.8 -377.2 -473.3 

ΔIndirect A/C CO2(MMT CO2 EQ) -11.0 -21.3 -27.5 -34.4 

Δ Direct A/C HFC (MMT CO2 EQ) -13.5 -27.2 -32.1 -34.9 

Δ CH4 (MMT CO2 EQ) 0.0 0.0 0.0 0.0 

Δ N2O (MMT CO2 EQ) 0.0 0.0 0.1 0.1 

Δ Total GHG (MMT CO2 EQ) -171.3 -339.2 -436.6 -542.4 

 

Upstream 

Δ CO2 (MMT CO2 EQ) -38.4 -75.9 -98.4 -123.4 

Δ CH4 (MMT CO2 EQ) -5.5 -10.7 -14.0 -17.4 

Δ N2O (MMT CO2 EQ) -0.1 -0.4 -0.4 -0.5 

Δ Total GHG -44.0 -87.0 -112.7 -141.4 

Total 

Δ Total GHG -215.2 -426.2 -549.3 -683.9 

Δ Fuel Consumption (Annual, Billion gallons) -17.8 -35.1 -45.5 -57.1 
Emissions Impacts 

5-39 

Table 5-40 –MY Lifetime GHG Emissions and Fuel Consumption vs. Reference Case 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

MY 

2016 

Program 

Total 

Downstream 

Δ CO2 excluding indirect A/C controls 

(MMT CO2 EQ) -36.5 -96.8 -162.5 -225.7 -292.9 -814.4 

ΔIndirect A/C CO2(MMT CO2 EQ) -5.3 -9.0 -12.9 -17.9 -20.3 -65.4 

Δ Direct A/C HFC (MMT CO2 EQ) -6.9 -11.7 -16.7 -23.2 -26.3 -84.9 

Δ CH4 (MMT CO2 EQ) 0.0 0.0 0.0 0.0 0.0 0.1 

Δ N2O (MMT CO2 EQ) 0.0 0.0 0.1 0.1 0.1 0.4 

Δ Total GHG (MMT CO2 EQ) -48.7 -117.5 -192.0 -266.7 -339.3 -964.2 

 

Upstream 

Δ CO2 (MMT CO2 EQ) -10.2 -25.7 -42.6 -59.2 -76.1 -213.9 

Δ CH4 (MMT CO2 EQ) -1.2 -3.1 -5.1 -7.1 -9.1 -25.5 

Δ N2O (MMT CO2 EQ) -0.1 -0.1 -0.2 -0.3 -0.4 -1.1 

Δ Total GHG -11.4 -28.9 -47.9 -66.6 -85.6 -240.4 

 

Total 

Δ Total GHG -60.2 -146.4 -239.9 -333.3 -424.9 -1204.7 

Δ Fuel Consumption (Annual, Billion 

gallons) -4.7 -11.9 -19.7 -27.4 -35.2 -99.0 
Draft Regulatory Impact Analysis 

5-40 

5.A Appendix to Chapter 5: Details of the TLAAS Impacts Analysis 

5.A.1 Introduction and Summary 

The TLAAS program allows manufacturers with total domestic sales of less than 

400,000 vehicles during model year 2009 to place up to 100,000 vehicles from model years 

2012-2015 into a separate fleet. This separate fleet is subject to a 25% less stringent standard 

than the manufacturer’s primary fleet (subject to various further constraints described in 

section III of the preamble and in the proposed rule itself). 

Several manufacturer decisions and marketplace events determine the impacts of the 

TLAAS program. This appendix presents a sensitivity analysis that brackets the impact of the 

program, and provides additional details on the assumptions made in the EPA emission 

analysis. 

Although the bracketing analyses presented here range from 0 to 25 MMT of CO2 

emissions, in all cases the TLAAS program has a proportionally small impact (< 3%) on the 

total program benefits over the model years 2012-2016. 

Under the estimation procedure used in the emission inventory analysis (as opposed to 

the bracketing analysis mentioned immediately above), the TLAAS is projected to result in an 

approximately 3.4 MMT decrease in greenhouse gas benefits from this rule over the lifetime 

of vehicles manufactured in model years 2012-2015 (assuming that it is technically feasible 

for all TLAAS-eligible producers to meet the otherwise-applicable GHG standards for those 

years, a dubious assumption given the very short lead times available). 

5.A.2 Factors Determining the Impact of the TLAAS 

The greatest challenge to accurately estimating the impacts of the TLAAS are 

uncertainties about manufacturer eligibility and manufacturer usage of the program. There is 

a third, albeit smaller uncertainty, concerning the size of the vehicles placed in the program. 

Eligibility

Up to eleven major manufacturers are potentially eligible for TLAAS based on 

preliminary EPA analysis of projected domestic sales for model year 2009. These 

manufacturers are Porsche, Tata, Mazda, Mitsubishi, Suzuki, Daimler, Subaru, BMW, 

Volkswagen, Hyundai, and Kia. 

Manufacturers such as Hyundai, Kia, Mazda, and Volkswagen are preliminarily 

estimated at 2009 domestic sales bordering 400,000. If none of these four manufacturers are 

eligible for the TLAAS program, the program covers up to 700,000 vehicles. If all four are 

included, the program increases in size by approximately 50% to 1.1 million vehicles. 
Emissions Impacts 

5-41 

The impacts of the program therefore partially depend on manufacturer eligibility. 

Manufacturer Usage 

By reducing the compliance burden, the TLAAS provides needed lead time flexibility 

to manufacturers in order to comply with the Light Duty Vehicle Greenhouse Gas Program in 

the short term, and provides needed lead time for these manufacturers to bring their entire 

fleet into compliance with the stringent 2016 MY standards. However, it is unclear whether 

manufacturers will participate in the TLAAS program to the fullest extent allowed, as there 

are two disincentives to fully utilizing the TLAAS. 

Vehicles in the TLAAS fleet may consume more fuel than comparably sized vehicles 

in the primary fleet. Assuming consumers place some weight on fuel economy when 

purchasing a vehicle, manufacturers with TLAAS fleets may thus place their vehicles at a 

competitive disadvantage in the marketplace. 

Further, at the cessation of the TLAAS program, manufacturers will need their fleet to 

meet the more stringent main program standards. If a manufacturer takes full advantage of 

the program by using the maximum 25% additional emission allotment, they may place 

themselves at a technological disadvantage when the program ends. Both in terms of 

engineering and manufacturing, a manufacturer is unlikely to want to fall behind its 

competitors. To avoid this scenario, a manufacturer may make gradual gains over the 

TLAAS program, and gradually use less of the 25% additional emission allotment. 

Because of these disincentives, manufacturers may likewise choose to not fully utilize 

the TLAAS vehicle production volumes. 

Size and Classification of the Vehicles Placed in the TLAAS Fleet

As the TLAAS program allows 25% additional emissions over the footprint-based 

main fleet standards, the size of the vehicles placed in the TLAAS fleet is significant. If a 

manufacturer places small but high emitting vehicles in the TLAAS fleet (ie, Porsche 

Carrera), the impact of the program is less than if large and high emitting vehicles are placed 

in the TLAAS fleet. 

A manufacturer who utilized the TLAAS fleet for small vehicles would necessarily 

have a proportionally lower net impact. Similarly, due to the two distinct footprint curves, the 

choice whether to place cars or trucks in the TLAAS fleet will also determine impact. 

5.A.3 Bounding Analysis of TLAAS Impact 

This section provides upper and lower bounds for the potential impacts from the 

TLAAS, and then describes the inputs used in the emission analysis. 

TLAAS is an optional program which can be used for a limited number of eligible 

vehicles to achieve compliance with the Light Duty Vehicle Greenhouse Gas Program. 
Draft Regulatory Impact Analysis 

5-42 

Consequently, no manufacturer is obligated to use the program, and the lower bound of the 

program impact could theoretically be zero. This is considered a highly unlikely scenario, as 

several manufacturers are anticipated to use the TLAAS to meet their compliance targets 

given the lack of lead time for these manufacturers to make the major conversions necessary 

to meet the standards. 

Conversely, as an upper bound, every manufacturer could use their full allocation on 

their largest vehicle, could potentially increase sales of those vehicles to 100,000 over the four 

year period, and could use the full 25% “cushion” for each of these vehicles. This is also an 

unlikely scenario, as it would require companies such as Porsche and BMW to sell specific 

vehicle models (such as the Porsche Boxster, or the Rolls Royce Phantom) in unprecedented 

numbers. 

As a boundary analysis, EPA analyzed these upper and lower bound scenarios . The 

GHG savings from the lower bound program was estimated at 950 MMT GHG reduced over 

lifetime of model years 2012-2016 (i.e. impact of the TLAAS is zero), while the upper bound 

impact was 925 MMT GHG reduced over the same period. Thus, the maximum potential 

impact of the program, even under this most extreme scenario is approximately 25 MMT. 

As noted, neither of these scenarios is remotely likely. However, the point of the 

bounding analysis is to show that the greatest possible impact of the proposed TLAAS is still 

relatively minimal. 

5.A.4 Approach used for Estimating TLAAS Impact 

Having bounded the analysis, a third approach was used for the emission modeling 

described in DRIA chapter 5. In this analysis, all eleven manufacturers were assumed to use 

the default vehicle allocation schedule from the TLAAS. This is a conservative estimate, as 

several of the manufacturers are unlikely to utilize their allocation due to either lack of need, 

or the disincentives discussed above. 

 

Table 5-41:TLAAS Default Vehicle Production Volumes 

MODEL 

YEAR 

2012 2013 2014 2015 

Sales Volume 40,000 30,000 20,000 10,000 
Emissions Impacts 

5-43 

The allocation was split evenly between cars and trucks for each manufacturer. The 

TLAAS fleet was assumed to emit as much CO2 per mile as expected from the largest 

footprint car or truck in each manufacturer’s fleet. This estimate combines the impact of the 

25% additional emission allotment and the vehicle size factors discussed above. These 

vehicles were then proportionally averaged into the manufacturer’s GHG score. This resulted 

in an emission impact of approximately 3.4 MMT CO2 over the lifetime of the 2012-2015 

MY vehicles. 

The gram per mile impacts are listed here for each of these scenarios. 

 TLAAS impact (Grams CO2 

Emissions Per Mile) 

Model Year Lower 

Bound 

Scenario 

Upper 

Bound 

Scenario 

Estimate 

Used In 

Emission 

Analysis 

2012 0 2.0 0.3

2013 0 1.5 0.2

2014 0 1.0 0.2

2015 0 0.5 0.1

2016 0 0 0.0
Draft Regulatory Impact Analysis 

5-44 

References

All references can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472.

 1

 Argonne National Laboratory. The Greenhouse Gases, Regulated Emissions, and Energy Use in 

Transportation (GREET) Model versions 1.7 and 1.8. 

http://www.transportation.anl.gov/modeling_simulation/GREET/ 

2

 Mcculloch A.; Lindley A. A. From mine to refrigeration: a life cycle inventory analysis of the production of 

HFC-134a .. ; International journal of refrigeration 2003, vol. 26, no8, pp. 865-872 

3

 Intergovernmental Panel on Climate Change. Chapter 2. Changes in Atmospheric Constituents and in 

Radiative Forcing. September 2007. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf 

4

 EPA. Draft MOVES 2009. http://www.epa.gov/otaq/models/moves/index.htm 

5

 U.S. EPA 2009. Updated OMEGA Post-Processor Spreadsheet. August 15, 2009. 

6

 Updated Tables to MOVES in Docket. Samplevehiclepopulation and emissionbyage. 

7

 John Koupal, Richard Rykowski, Todd Sherwood, Ed Nam. “Documentation of Updated Light-duty Vehicle 

GHG Scenarios.” Memo to Docket ID No. EPA-HQ-OAR-2008-0318 

8

 MOVES documentation and technical documents can be seen at 

http://www.epa.gov/otaq/models/moves/index.htm. 

9

 Reference OMEGA Peer Review 

10 U.S. EPA. Draft Regulatory Impact Analysis: Changes to Renewable Fuel Standard Program. Chapters 2 

and 3.May 26, 2009. 

11 Argonne National Laboratory. The Greenhouse Gases, Regulated Emissions, and Energy Use in 

Transportation (GREET) Model versions 1.7 and 1.8. 

http://www.transportation.anl.gov/modeling_simulation/GREET/ 

12 U.S. EPA. 2008. RFS2 Modified version of GREET1.7 Upstream Emissions Spreadsheet, October 31, 2008. 

13 U.S. EPA, Achieved CO2 standards worksheet. 2009. 

14 NHTSA. 2009. Average Fuel Economy Standards, Passenger Cars and Light Trucks, Model Year 2011. 

Docket ID: NHTSA-2009-0062-0001. 

http://www.nhtsa.dot.gov/portal/nhtsa_static_file_downloader.jsp?file=/staticfiles/DOT/NHTSA/Rulemaking/Ru

les/Associated Files/CAFE_Updated_Final_Rule_MY2011.pdf 

15 NHTSA. 2009. Average Fuel Economy Standards, Passenger Cars and Light Trucks, Model Year 2011. 

http://www.nhtsa.dot.gov/portal/nhtsa_static_file_downloader.jsp?file=/staticfiles/DOT/NHTSA/Rulemaking/Ru

les/Associated Files/CAFE_Updated_Final_Rule_MY2011.pdf 

16U.S. EPA. Baseline and Reference Fleet File, as documented in TSD chapter 1. August 2009.. 

17 Energy Information Administration. Annual Energy Outlook 2009. Supplemental Transportation Tables. 

April 2009. http://www.eia.doe.gov/oiaf/aeo/supplement/sup_tran.xls 
Emissions Impacts 

5-45 

 

18 NHTSA. 2009. Average Fuel Economy Standards, Passenger Cars and Light Trucks, Model Year 2011. 

Docket ID: NHTSA-2009-0062-0001. 

http://www.nhtsa.dot.gov/portal/nhtsa_static_file_downloader.jsp?file=/staticfiles/DOT/NHTSA/Rulemaking/Ru

les/Associated Files/CAFE_Updated_Final_Rule_MY2011.pdf 

19 NHTSA. 2009. Average Fuel Economy Standards, Passenger Cars and Light Trucks, Model Year 2011. 

Docket ID: NHTSA-2009-0062-0001. 

http://www.nhtsa.dot.gov/portal/nhtsa_static_file_downloader.jsp?file=/staticfiles/DOT/NHTSA/Rulemaking/Ru

les/Associated Files/CAFE_Updated_Final_Rule_MY2011.pdf 

20 U.S. EPA. Baseline and Reference Fleet File, as documented in TSD chapter 1. August 2009.. 

21 EPA. Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel. 

EPA420-F-05-001 February 2005 

22 U.S. EPA. Baseline and Reference Fleet File, as documented in TSD chapter 1. August 2009.. 

23 Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy. Transportation 

Energy Data Book: Edition 27. Chapter 4. 2008. 

24 NHTSA. Vehicle Survivability and Travel Mileage Schedules. 2006. 

25 Draft TSD Chapter 4 

26 NHTSA. Vehicle Survivability and Travel Mileage Schedules. 2006. 

27 Draft TSD Chapter 4 

28 EPA. Final Technical Support Document.Fuel Economy Labeling of Motor Vehicle Revisions to Improve 

Calculation of Fuel Economy Estimates 

29 John Koupal, Richard Rykowski, Todd Sherwood, Ed Nam. “Documentation of Updated Light-duty Vehicle 

GHG Scenarios.” Memo to Docket ID No. EPA-HQ-OAR-2008-0318 

30 Draft RIA chapter 2. 

31 Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy. Transportation Energy Data 

Book: Edition 27. 2008. 

32 EPA. Final Technical Support Document. Fuel Economy Labeling of Motor Vehicle Revisions to Improve 

Calculation of Fuel Economy Estimates 

33 Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel. EPA420-F-05-001 February 

2005. http://www.epa.gov/otaq/climate/420f05001.htm 

34 Craig Harvey, EPA, “Calculation of Upstream Emissions for the GHG Vehicle Rule.” 2009. 

35 Control of Emissions of Air Pollution From Locomotive Engines and Marine Compression-Ignition Engines 

Less Than 30 Liters per Cylinder, Republication, Final Rule (Federal Register Vol 73, No. 126, page 37096, 

June 30, 2008). 

36 Control of Emissions From Nonroad Spark-Ignition Engines and Equipment, Final Rule (Federal Register Vol 

73, No. 196, page 59034, October 8, 2008). 
Draft Regulatory Impact Analysis 

5-46 

 37 Draft Regulatory Impact Analysis: Control of Emissions of Air Pollution from Category 3 Marine Diesel 

Engines, Chapter 3. This is available in Docket OAR-2007-0121at http://www.regulations.gov/ 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-1 

CHAPTER 6:Vehicle Program Costs Including Fuel 

Consumption Impacts 

This chapter presents the costs of the proposed GHG vehicle program including the 

costs associated with addition of new technology and savings associated with improved fuel 

consumption. In section 6.1, vehicle compliance costs are presented on a per-car and pertruck basis for each manufacturer and the industry as a whole. Vehicle compliance costs are 

also presented on an annual basis for each manufacturer and the industry as a whole. Where 

appropriate, net present values are presented at both a 3 percent and a 7 percent discount rate 

for annual costs in the years 2012 through 2050. In section 6.2, the cost per ton of GHG 

reduced is presented as a result of the proposal. In section 6.3, fuel consumption impacts are 

presented on a per-year basis for cars and trucks in terms of gallons saved and in terms of 

dollars saved. In section 6.4, the vehicle program costs and fuel consumption impacts are 

summarized. This chapter does not present costs associated with noise, congestion, accidents 

and other economic impacts associated with increased driving that could result from the 

proposed program. Such impacts are presented in Chapter 8 of this draft RIA. 

6.1 Vehicle Program Costs 

Chapter 4 of this draft RIA presents the outputs of the OMEGA model for the model 

year 2016. Here, we build on those results and calculate estimated costs for each model year 

beginning with 2012 and going through 2050. We do this both on a per-vehicle basis and an 

annual basis. Costs here include costs associated with the proposed A/C credit program. For 

details on the individual technology costs please refer to Chapter 3 of the draft joint TSD. For 

details on the OMEGA model inputs (i.e., how the individual technology costs are combined 

into package costs) please refer to Chapter 1 of this draft RIA. For details on the A/C costs, 

please refer to Chapter 2 of this draft RIA. 

6.1.1 Vehicle Compliance Costs on a Per-Vehicle Basis 

As stated above, Chapter 4 of this draft RIA presents the cost per vehicle for each 

manufacturer in the 2016 model year. Those 2016 MY costs are reproduced in Table 6-1. To 

estimate the cost per vehicle for model years 2012 through 2015, we first looked at the 

projected CO2 levels for each manufacturer’s fleet for each year 2011 though 2016. Those 

CO2 levels are presented in Table 6-2 for cars and Table 6-3 for trucks.A The achieved CO2 

levels for 2012-2015 were derived using the same process described in chapter 5 of the DRIA. 

Starting with the calculated manufacturer, vehicle class, and model year specific achieved 

standards, we estimated the cost effective environmentally neutral credit trading based on the 

 A Note that the 2012-2015 CO2 levels are estimates based upon assumptions of manufacturer fleetwide CO2 

averages in 2011, which are extrapolated from a 2008 base fleet. Consequently, the average CO2 emission 

levels for some manufacturers are potentially too high for the 2011MY which makes the transition to the 

2012MY appear as a more significant change. As a result, 2012MY costs represent a large percentage of the 

total costs. As an example, the 2012MY cost for Suzuki as shown in Table 6-5 is approximately 60% of the 

2016MY cost. In reality, the transition between MY 2011 and MY 2016 may be significantly smoother, and is 

likely to be smoother due to multiyear planning. 
Regulatory Impact Analysis 

6-2 

2016 achieved levels predicted by OMEGA. Based on this process, we projected the most 

likely achieved levels for 2012-2015 for each manufacturer. 

There are some differences between cost effective achieved levels and the achieved 

levels shown in DRIA chapter 5. As shown here, the cost effective achieved levels for the 

intermediate years were derived in the following manner. MY 2011 baseline CO2 was 

determined from the reference fleet file.1

 MY 2016 achieved CO2 was determined from the 

OMEGA output described in DRIA chapter 4. To determine the intermediate years, an 

interpolation was performed between these two points. Two different forms of interpolation 

were used. For manufacturers that fully comply with the 2016 standards, the change between 

2011 and 2016 was weighted by the percent change in their achieved target for each year (as 

determined in DRIA chapter 5). For the manufacturers that do not fully comply in 2016, 

these manufacturers improved by 20% of their total change each year. 

Two manufacturers, Subaru and Mitsubishi, had their improvement front loaded in 

order to produce early year compliance. These companies are anticipated to comply with the 

intermediate year standards, but the 2008 base fleet may understate their expected 

performance.B

 The analysis behind the cost effective achieved levels is contained in the EPA 

docket.2

We then used these CO2 values to generate ratios that could be applied to the 2016 

MY costs to arrive at cost estimates for each of the intervening years. This methodology is 

based, in part, on the credit carry-forward and carry-back provisions contained in the 

proposal. However, we must also remember that the technology costs and, subsequently, the 

package costs in the 2016 MY have undergone some learning effects as described in Chapter 

3 of the draft joint TSD. We compared the 2016 MY package costs to each of the intervening 

years and the results, on a percentage basis, are shown in Table 6-4. We have also done this 

for the years following 2016 to reflect the effects of the near term and long term ICMs as 

described in Chapter 3 of the draft joint TSD. The process for estimating costs in the 

intervening years is best understood by way of an example: General Motors cars are 

estimated to incur a cost of $969 in the 2016 MY while achieving a CO2 average of 240 g/mi; 

for the 2011 and 2012 MYs, GM cars are projected to achieve a CO2 average of 306 and 276, 

respectively. We can apply the ratio (306-276)/(306-240)=0.45 to GM’s 2016 cost of $969, 

and then apply the 2012 relative to 2016 cost factor of 117%, to arrive at an estimated 2012 

cost of $507.C

 We then carry out this process for each manufacturer for each year to arrive at 

the results presented in Table 6-5 for cars, Table 6-6 for trucks, and Table 6-7 for cars and 

trucks combined. Table 6-8 shows the industry average cost per car, cost per truck, and cost 

per vehicle (car/truck combined) for the 2012 and later model years.D

 B Ibid. 

C

 Numbers in the text are rounded for clarity so results using numbers shown in the text may not match those in 

tables. 

D Note that the costs per car, truck and vehicle presented here do not include possible maintenance savings 

associated with the new A/C systems. They also do not include maintenance costs associated with low friction 

lubes and low rolling resistenance tires. We include higher new vehicle costs for these latter items but do not 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-3 

Table 6-1 Cost per Car and Truck, including A/C, for the 2016 MY (2007 dollars) 

MANUFACTURER $/CAR $/TRUCK

BMW $1,700 $1,664 

Chrysler $1,331 $1,505 

Daimler $1,630 $1,356 

Ford $1,434 $1,485 

GeneralMotors $969 $1,781 

Honda $606 $695 

Hyundai $739 $1,679 

Kia $741 $1,177 

Mazda $946 $1,029 

Mitsubishi $1,067 $1,263 

Nissan $1,012 $1,193 

Porsche $1,548 $666 

Subaru $902 $1,328 

Suzuki $1,093 $1,263 

Tata $1,269 $673 

Toyota $599 $435 

Volkswagen $1,626 $949 

Overall $968 $1,213 

Table 6-2 Projected CO2 Levels for MYs 2011-2016, Cars Only (g/mi CO2) 

MANUFACTURER 2011MY 2012MY 2013MY 2014MY 2015MY 2016MY

BMW 308.0 292.5 278.2 263.3 248.4 235.3 

Chrysler 313.1 279.0 270.2 261.3 250.0 219.6 

Daimler 308.6 293.1 278.8 263.9 249.0 236.0 

Ford 311.0 276.5 268.3 259.5 246.2 226.4 

GeneralMotors 305.8 276.4 267.7 259.1 246.0 239.8 

Honda 263.2 251.2 240.3 228.9 217.4 207.7 

Hyundai 282.2 260.0 251.8 243.5 232.3 226.8 

Kia 280.5 263.0 254.6 245.8 234.4 223.1 

Mazda 286.8 260.1 251.8 243.0 231.4 221.0 

Mitsubishi 287.1 258.1 246.5 231.0 215.6 211.7 

Nissan 278.4 262.7 255.1 246.9 235.8 217.4 

Porsche 339.1 317.9 297.9 277.3 256.7 237.9 

Subaru 304.0 272.9 258.6 249.9 241.3 231.3 

Suzuki 284.5 247.0 238.4 229.7 217.9 203.3 

Tata 347.3 328.9 311.8 294.1 276.4 260.4 

Toyota 250.9 240.5 231.3 221.5 211.7 203.7 

Volkswagen 291.5 278.3 266.4 253.8 241.2 230.4 

Overall 285.1 264.0 254.5 244.4 232.4 220.9 

 account for higher replacement costs during vehicle lifetimes even though oil is changed many times and tires 

are changed once or twice. We intend to include these maintenance costs and savings in our final rule analysis. 
Regulatory Impact Analysis 

6-4 

Table 6-3 Projected CO2 Levels for MYs 2011-2016, Trucks Only (g/mi CO2) 

MANUFACTURER 2011MY 2012MY 2013MY 2014MY 2015MY 2016MY

BMW 357.3 341.2 326.5 311.2 295.8 282.4 

Chrysler 386.7 365.7 354.6 344.0 326.5 314.1 

Daimler 423.0 397.6 373.7 349.0 324.3 301.7 

Ford 413.4 382.1 370.3 360.2 342.5 316.6 

GeneralMotors 410.5 392.7 380.8 369.3 351.0 308.4 

Honda 346.7 338.3 331.2 323.5 315.8 310.0 

Hyundai 357.6 330.6 320.3 308.4 293.1 257.6 

Kia 353.9 339.2 329.1 317.8 302.8 291.4 

Mazda 332.7 326.0 314.9 302.7 287.4 267.9 

Mitsubishi 337.2 327.2 322.4 317.9 311.5 307.0 

Nissan 387.3 370.3 358.9 348.7 331.1 321.5 

Porsche 369.6 361.0 353.7 345.8 337.9 332.0 

Subaru 334.9 294.4 275.9 264.9 254.0 240.9 

Suzuki 356.7 314.7 306.1 296.7 283.8 280.7 

Tata 362.5 355.2 349.3 342.7 336.1 331.5 

Toyota 353.4 345.8 339.6 332.8 325.9 321.0 

Volkswagen 417.6 398.9 381.5 363.4 345.3 329.2 

Overall 383.6 365.3 355.5 345.8 331.7 310.9 

 

Table 6-4 Package Costs Measured Relative to the Package Costs for the 2016MY 

YEAR PACKAGE COSTS 

RELATIVE TO 2016

2012 117% 

2013 115% 

2014 108% 

2015 102% 

2016 100% 

2017 100% 

2018 100% 

2019 100% 

2020 100% 

2021 100% 

2022+ 92% 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-5 

Table 6-5 Cost per Car, including A/C, by Manufacturer (2007 dollars) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY

BMW $426 $801 $1,130 $1,425 $1,700 

Chrysler $571 $703 $797 $918 $1,331 

Daimler $408 $768 $1,084 $1,367 $1,630 

Ford $686 $831 $945 $1,123 $1,434 

GeneralMotors $507 $643 $740 $897 $969 

Honda $155 $288 $406 $512 $606 

Hyundai $348 $466 $558 $680 $739 

Kia $265 $385 $484 $608 $741 

Mazda $451 $578 $681 $814 $946 

Mitsubishi $483 $661 $858 $1,035 $1,067 

Nissan $306 $446 $566 $724 $1,012 

Porsche $381 $725 $1,022 $1,289 $1,548 

Subaru $454 $648 $726 $796 $902 

Suzuki $593 $713 $798 $916 $1,093 

Tata $315 $596 $841 $1,060 $1,269 

Toyota $155 $286 $404 $509 $599 

Volkswagen $412 $770 $1,086 $1,369 $1,626 

Overall $374 $531 $663 $813 $968 

Table 6-6 Cost per Truck, including A/C, by Manufacturer (2007 dollars) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY

BMW $420 $786 $1,109 $1,398 $1,664 

Chrysler $510 $763 $956 $1,276 $1,505 

Daimler $333 $634 $895 $1,128 $1,356 

Ford $564 $760 $882 $1,112 $1,485 

GeneralMotors $364 $596 $777 $1,061 $1,781 

Honda $188 $337 $475 $599 $695 

Hyundai $532 $720 $893 $1,107 $1,679 

Kia $325 $536 $735 $984 $1,177 

Mazda $125 $326 $515 $736 $1,029 

Mitsubishi $488 $709 $874 $1,101 $1,263 

Nissan $363 $592 $758 $1,042 $1,193 

Porsche $179 $323 $455 $574 $666 

Subaru $673 $959 $1,069 $1,169 $1,328 

Suzuki $820 $967 $1,079 $1,238 $1,263 

Tata $186 $330 $465 $586 $673 

Toyota $120 $213 $300 $378 $435 

Volkswagen $237 $446 $629 $794 $949 

Overall $358 $539 $682 $886 $1,213 
Regulatory Impact Analysis 

6-6 

Table 6-7 Cost per Vehicle (car/truck combined), including A/C, by Manufacturer (2007 dollars) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY

BMW $424 $797 $1,124 $1,418 $1,691 

Chrysler $534 $738 $887 $1,080 $1,408 

Daimler $376 $710 $998 $1,259 $1,509 

Ford $641 $806 $922 $1,119 $1,452 

GeneralMotors $443 $622 $756 $968 $1,311 

Honda $167 $305 $428 $538 $632 

Hyundai $384 $516 $623 $759 $907 

Kia $304 $473 $635 $813 $973 

Mazda $384 $529 $651 $801 $959 

Mitsubishi $484 $670 $861 $1,045 $1,095 

Nissan $328 $501 $639 $829 $1,070 

Porsche $354 $661 $944 $1,201 $1,444 

Subaru $527 $747 $831 $905 $1,023 

Suzuki $683 $806 $892 $1,019 $1,147 

Tata $281 $528 $738 $935 $1,117 

Toyota $142 $260 $368 $465 $545 

Volkswagen $376 $712 $1,003 $1,265 $1,508 

Overall $368 $534 $670 $838 $1,050 

Table 6-8 Industry Average Cost per Car, Truck, and Combined by Year (2007 dollars) 

YEAR $/CAR $/TRUCK $/VEHICLE

2012 $374 $358 $368 

2013 $531 $539 $534 

2014 $663 $682 $670 

2015 $813 $886 $838 

2016 $968 $1,213 $1,050 

2017 $968 $1,213 $1,047 

2018 $968 $1,213 $1,044 

2019 $968 $1,213 $1,042 

2020 $968 $1,213 $1,040 

2021 $968 $1,213 $1,039 

2022 $890 $1,116 $955 

2023 $890 $1,116 $955 

2024 $890 $1,116 $955 

2025 $890 $1,116 $955 

2026 $890 $1,116 $954 

2027 $890 $1,116 $954 

2028 $890 $1,116 $954 

2029 $890 $1,116 $953 

2030 $890 $1,116 $953 

2031 $890 $1,116 $953 

2032 $890 $1,116 $953 

2033 $890 $1,116 $953 

2034 $890 $1,116 $953 

2035 $890 $1,116 $953 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-7 

2036 $890 $1,116 $953 

2037 $890 $1,116 $953 

2038 $890 $1,116 $953 

2039 $890 $1,116 $953 

2040 $890 $1,116 $953 

2041 $890 $1,116 $953 

2042 $890 $1,116 $953 

2043 $890 $1,116 $953 

2044 $890 $1,116 $953 

2045 $890 $1,116 $953 

2046 $890 $1,116 $953 

2047 $890 $1,116 $953 

2048 $890 $1,116 $953 

2049 $890 $1,116 $953 

2050 $890 $1,116 $953 

6.1.2 Vehicle Compliance Costs on a Per-Year Basis 

Given the cost per car and cost per truck estimates shown in Table 6-5 and Table 6-6, 

respectively, we can calculate annual costs by multiplying by estimated sales. Table 6-9 

shows projected car sales by manufacturer for model years 2012-2016. Table 6-10 shows 

projected truck sales by manufacturer for model years 2012-2016. Table 6-11 shows 

combined sales by manufacturer for 2012-2016. Table 6-11 shows annual costs attributable 

to cars by manufacturer for MYs 2012-2016, Table 6-12 shows the same for trucks, and Table 

6-13 shows the same for cars and trucks combined. Table 6-14 then shows the annual costs 

by the entire industry for cars, trucks, and total for the years 2012 through 2050 with net 

present values using both a 3 percent and a 7 percent discount rate.E

 

 E

 Note that the vehicle compliance costs presented here do not include costs associated with upgrading testing 

facilities to accommodate N2O testing. While including those costs would likely have very little impact on the 

costs presented here for new vehicle technology, the costs should be included and we intend to do so in the final 

rule analysis. 
Regulatory Impact Analysis 

6-8 

Table 6-9 Estimated Annual Car Sales by Manufacturer (# of Units) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY 

BMW 283,471 323,191 352,248 371,668 380,804 

Chrysler 178,635 175,072 169,046 136,583 138,602 

Daimler 1,348,260 1,424,345 1,446,097 1,503,175 1,511,354 

Ford 149,192 135,946 135,141 130,588 131,022 

General Motors 1,484,580 1,620,301 1,708,507 1,789,813 1,820,234 

Honda 1,155,008 1,352,607 1,493,242 1,562,496 1,593,092 

Hyundai 580,538 558,975 562,862 590,579 596,891 

Kia 22,878 32,822 35,534 40,586 41,584 

Mazda 304,524 309,667 331,198 347,533 351,081 

Mitsubishi 313,489 318,669 338,487 340,069 345,489 

Nissan 172,172 190,133 204,335 229,562 235,205 

Porsche 64,843 61,169 56,478 52,368 53,459 

Subaru 958,696 1,031,569 1,073,307 1,104,272 1,123,486 

Suzuki 31,605 35,813 38,470 36,175 37,064 

Tata 86,537 86,220 81,480 75,965 77,427 

Toyota 1,697,762 1,862,201 1,985,033 2,114,273 2,154,115 

Volkswagen 423,433 458,641 467,885 465,263 476,699 

Industry 9,255,624 9,977,341 10,479,350 10,890,967 11,067,608 

Table 6-10 Estimated Annual Truck Sales by Manufacturer (# of Units) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY 

BMW 142,861 141,949 144,022 139,034 135,569 

Chrysler 282,472 244,441 222,545 112,381 109,674 

Daimler 1,025,575 1,107,535 1,202,141 1,230,889 1,202,442 

Ford 88,877 77,593 76,913 73,425 74,135 

General Motors 1,209,642 1,320,438 1,342,856 1,355,820 1,322,512 

Honda 669,948 724,500 687,208 691,641 675,173 

Hyundai 141,028 135,751 134,274 132,978 129,763 

Kia 42,168 46,256 53,335 48,583 47,372 

Mazda 78,789 74,596 72,192 69,894 68,310 

Mitsubishi 71,930 71,136 66,919 59,361 57,998 

Nissan 109,351 115,684 125,189 113,366 110,541 

Porsche 10,098 11,440 9,124 7,349 7,171 

Subaru 477,897 478,571 474,558 454,488 444,471 

Suzuki 20,767 20,639 19,379 16,822 17,273 

Tata 30,391 29,750 30,545 27,204 26,526 

Toyota 1,019,375 1,019,048 1,045,671 1,081,323 1,057,837 

Volkswagen 109,415 100,952 104,023 102,743 100,186 

Industry 5,530,583 5,720,280 5,810,895 5,717,300 5,586,953 

 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-9 

Table 6-11 Estimated Annual Costs by Manufacturer, including A/C, for Cars ($Millions of 2007 dollars) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY 

BMW $120 $260 $400 $530 $650 

Chrysler $100 $120 $130 $130 $180 

Daimler $70 $150 $220 $310 $380 

Ford $930 $1,180 $1,370 $1,690 $2,170 

General Motors $750 $1,040 $1,260 $1,600 $1,760 

Honda $180 $390 $610 $800 $960 

Hyundai $200 $260 $310 $400 $440 

Kia $80 $120 $160 $210 $260 

Mazda $140 $180 $230 $280 $330 

Mitsubishi $30 $40 $50 $50 $60 

Nissan $290 $460 $610 $800 $1,140 

Porsche $10 $30 $40 $50 $60 

Subaru $70 $90 $100 $100 $120 

Suzuki $50 $60 $60 $70 $80 

Tata $10 $20 $30 $40 $50 

Toyota $260 $530 $800 $1,080 $1,290 

Volkswagen $170 $350 $510 $640 $780 

Industry $3,460 $5,300 $6,950 $8,850 $10,710 

Table 6-12 Estimated Annual Costs by Manufacturer, including A/C, for Trucks ($Millions of 2007 

dollars) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY 

BMW $60 $110 $160 $190 $230 

Chrysler $140 $190 $210 $140 $170 

Daimler $40 $70 $110 $130 $150 

Ford $580 $840 $1,060 $1,370 $1,790 

General Motors $440 $790 $1,040 $1,440 $2,360 

Honda $130 $240 $330 $410 $470 

Hyundai $80 $100 $120 $150 $220 

Kia $30 $40 $50 $70 $80 

Mazda $10 $20 $30 $40 $60 

Mitsubishi $0 $10 $10 $10 $10 

Nissan $170 $280 $360 $470 $530 

Porsche $0 $10 $10 $10 $10 

Subaru $60 $70 $80 $90 $100 

Suzuki $20 $30 $30 $30 $30 

Tata $10 $20 $20 $30 $30 

Toyota $120 $220 $310 $410 $460 

Volkswagen $30 $50 $70 $80 $100 

Industry $1,980 $3,090 $3,960 $5,060 $6,780 
Regulatory Impact Analysis 

6-10 

Table 6-13 Estimated Annual Costs by Manufacturer, including A/C, for Cars and Trucks Combined 

($Millions of 2007 dollars) 

MANUFACTURER 2012MY 2013MY 2014MY 2015MY 2016MY 

BMW $180 $370 $560 $720 $880 

Chrysler $240 $310 $340 $270 $350 

Daimler $110 $220 $330 $440 $530 

Ford $1,510 $2,020 $2,430 $3,060 $3,960 

General Motors $1,190 $1,830 $2,300 $3,040 $4,120 

Honda $310 $630 $940 $1,210 $1,430 

Hyundai $280 $360 $430 $550 $660 

Kia $110 $160 $210 $280 $340 

Mazda $150 $200 $260 $320 $390 

Mitsubishi $30 $50 $60 $60 $70 

Nissan $460 $740 $970 $1,270 $1,670 

Porsche $10 $40 $50 $60 $70 

Subaru $130 $160 $180 $190 $220 

Suzuki $70 $90 $90 $100 $110 

Tata $20 $40 $50 $70 $80 

Toyota $380 $750 $1,110 $1,490 $1,750 

Volkswagen $200 $400 $580 $720 $880 

Industry $5,440 $8,390 $10,910 $13,910 $17,490 

Table 6-14 Annual Sales & Costs for Cars & Trucks (Monetary Values in 2007 dollars) 

YEAR CAR SALES TRUCK SALES CAR COSTS 

($MILLIONS)

TRUCK COSTS 

($MILLIONS) 

TOTAL COSTS 

($MILLIONS) 

2012 9,255,624 5,530,583 $3,460 $1,980 $5,440 

2013 9,977,341 5,720,280 $5,300 $3,090 $8,390 

2014 10,479,350 5,810,895 $6,950 $3,960 $10,910 

2015 10,890,967 5,717,300 $8,850 $5,060 $13,910 

2016 11,067,608 5,586,953 $10,710 $6,780 $17,490 

2017 11,398,169 5,403,989 $11,030 $6,560 $17,590 

2018 11,684,257 5,282,864 $11,310 $6,410 $17,720 

2019 11,948,850 5,191,459 $11,570 $6,300 $17,870 

2020 12,190,082 5,088,666 $11,800 $6,170 $17,970 

2021 12,184,615 5,018,346 $11,790 $6,090 $17,880 

2022 12,224,907 4,966,015 $10,880 $5,540 $16,420 

2023 12,393,064 4,990,624 $11,030 $5,570 $16,600 

2024 12,615,769 5,057,793 $11,230 $5,640 $16,870 

2025 12,867,956 5,154,435 $11,450 $5,750 $17,200 

2026 13,056,941 5,196,282 $11,620 $5,800 $17,420 

2027 13,146,812 5,220,321 $11,700 $5,830 $17,530 

2028 13,245,293 5,211,789 $11,790 $5,820 $17,610 

2029 13,390,625 5,172,196 $11,920 $5,770 $17,690 

2030 13,550,044 5,250,009 $12,060 $5,860 $17,920 

2031 13,653,024 5,289,909 $12,150 $5,900 $18,050 

2032 13,756,787 5,330,112 $12,250 $5,950 $18,200 

2033 13,861,339 5,370,621 $12,340 $5,990 $18,330 

2034 13,966,685 5,411,438 $12,430 $6,040 $18,470 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-11 

2035 14,072,832 5,452,565 $12,530 $6,080 $18,610 

2036 14,179,785 5,494,004 $12,620 $6,130 $18,750 

2037 14,287,552 5,535,759 $12,720 $6,180 $18,900 

2038 14,396,137 5,577,830 $12,820 $6,220 $19,040 

2039 14,505,548 5,620,222 $12,910 $6,270 $19,180 

2040 14,615,790 5,662,936 $13,010 $6,320 $19,330 

2041 14,726,870 5,705,974 $13,110 $6,370 $19,480 

2042 14,838,794 5,749,339 $13,210 $6,420 $19,630 

2043 14,951,569 5,793,034 $13,310 $6,460 $19,770 

2044 15,065,201 5,837,061 $13,410 $6,510 $19,920 

2045 15,179,696 5,881,423 $13,510 $6,560 $20,070 

2046 15,295,062 5,926,122 $13,620 $6,610 $20,230 

2047 15,411,305 5,971,160 $13,720 $6,660 $20,380 

2048 15,528,430 6,016,541 $13,820 $6,710 $20,530 

2049 15,646,447 6,062,267 $13,930 $6,770 $20,700 

2050 15,765,360 6,108,340 $14,030 $6,820 $20,850 

NPV, 3% $257,680 $132,320 $390,000 

NPV, 7% $141,860 $74,700 $216,550 

6.2 Cost per Ton of Emissions Reduced 

We have calculated the cost per ton of GHG (CO2 equivalent, or CO2e) reductions 

associated with this proposal using the costs shown in Table 6-14 and the emissions 

reductions described in Chapter 5. We have calculated the cost per metric ton of GHG 

emissions reductions in the years 2020, 2030, 2040, and 2050 using the annual vehicle 

compliance costs and emission reductions for each of those years. The value in 2050 represents the long-term cost per ton of the emissions reduced. Note that we have not included the 

savings associated with reduced fuel consumption, nor any of the other benefits of this 

proposal in the cost per ton calculations. If we were to include fuel savings in the cost 

estimates, the cost per ton would be less than $0, since the fuel savings outweigh the costs 

(see Section 6.3 below). With regard to the proposed CH4 and N2O standards, since these 

standards would be emissions caps designed to ensure manufacturers do not backslide from 

current levels, we have not estimated costs associated with the standards (since the standards 

would not require any change from current practices nor do we estimate they would result in 

emissions reductions). 

The results for CO2e costs per ton under the proposed vehicle program are shown in 

Table 6-15. 
Regulatory Impact Analysis 

6-12 

Table 6-15 Annual Cost Per Metric Ton of CO2e Reduced, in $2007 dollars 

YEAR COST 

($MILLIONS) * 

CO2-EQUIVLANET 

REDUCTION 

(MILLION METRIC 

TONS) 

COST PER TON 

2020 $18,000 170 $110 

2030 $17,900 320 $60 

2040 $19,300 420 $50 

2050 $20,900 520 $40 

*

 Costs here include vehicle compliance costs and do not include any fuel savings (discussed in section 6.3) or 

other benefits of this proposal (discussed in Chapter 8).

6.3 Fuel Consumption Impacts 

In this section, we present the impact of the proposed program on fuel consumption 

and the consumer savings realized due to the lower fuel consumption. Chapter 5 provides 

more detail on the estimated reduction in the gallons of fuel expected to be consumed as a 

result of the proposal. 

The proposed CO2 standards would result in significant improvements in the fuel 

efficiency of affected vehicles. Drivers of those vehicles would see corresponding savings 

associated with reduced fuel expenditures. We have estimated the impacts on fuel 

consumption for both the proposed tailpipe CO2 standards and the proposed A/C credit 

program. To do this, fuel consumption is calculated using both current CO2 emission levels 

and the proposed CO2 standards. The difference between these estimates represents the net 

savings from the proposed CO2 standards. 

The expected impacts on fuel consumption are shown in Table 6-16. The gallons 

shown in the tables reflect impacts from the proposed CO2 standards, including the proposed 

A/C credit program, and include increased consumption resulting from the rebound effect. 

Using these fuel consumption estimates, we can calculate the monetized fuel savings 

associated with the proposed CO2 standards. To do this, we multiply reduced fuel 

consumption in each year by the corresponding estimated average fuel price in that year, 

using the reference case taken from the AEO 2009. AEO is the government consensus 

estimate used by NHTSA and many other government agencies to estimate the projected price 

of fuel. We have included all fuel taxes in these estimates since these are the prices paid by 

consumers. As such, the savings shown reflect savings to the consumer. These results are 

also shown in Table 6-16. Note that we present the monetized fuel savings using pre-tax fuel 

prices in Chapter 8 of this draft RIA. The fuel savings based on pre-tax fuel prices reflect the 

societal savings in contrast to the consumer savings presented in Table 6-16. Also in Chapter 

8, we present the benefit-cost of the proposal and, for that reason, present the fuel impacts as 

negative costs of the program while here we present them as positive savings. 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-13 

Table 6-16 Annual Fuel Consumption Impacts of the Proposed Vehicle Standards and A/C Credit 

Programs 

 (Monetary values in 2007 dollars) 

YEAR GALLONS 

(MILLIONS) 

FUEL PRICE 

INCLUDING 

TAXES 

($/GALLON) 

SAVINGS 

($MILLIONS) 

2012 500 $2.70 $1,400

2013 1,300 $2.85 $3,800

2014 2,400 $3.00 $7,200

2015 3,900 $3.16 $12,400

2016 5,900 $3.27 $19,400

2017 7,900 $3.39 $26,700

2018 9,800 $3.48 $34,100

2019 11,600 $3.56 $41,300

2020 13,400 $3.62 $48,400

2021 15,000 $3.64 $54,600

2022 16,600 $3.67 $60,800

2023 18,100 $3.69 $66,700

2024 19,500 $3.69 $72,000

2025 20,900 $3.68 $76,800

2026 22,100 $3.72 $82,200

2027 23,300 $3.72 $86,500

2028 24,300 $3.76 $91,600

2029 25,300 $3.87 $97,800

2030 26,200 $3.82 $100,000

2031 27,000 $3.84 $103,800

2032 27,800 $3.86 $107,500

2033 28,600 $3.88 $111,100

2034 29,400 $3.90 $114,700

2035 30,100 $3.92 $118,300

2036 30,900 $3.95 $121,900

2037 31,600 $3.97 $125,500

2038 32,400 $3.99 $129,200

2039 33,200 $4.01 $133,000

2040 33,900 $4.03 $136,800

2041 34,700 $4.05 $140,700

2042 35,500 $4.07 $144,700

2043 36,300 $4.10 $148,800

2044 37,200 $4.12 $153,100

2045 38,000 $4.14 $157,400

2046 38,900 $4.16 $161,900

2047 39,800 $4.19 $166,500

2048 40,700 $4.21 $171,200

2049 41,600 $4.23 $176,100

2050 42,600 $4.25 $181,000

NPV, 3% $1,850,200

NPV, 7% $826,900
Regulatory Impact Analysis 

6-14 

As shown in Table 6-16, we are projecting that consumers would realize very large 

fuel savings as a result of the standards contained in today’s proposal. There are several ways 

to view this value. Some, as demonstrated below in Chapter 8 of this draft RIA, view these 

fuel savings as a reduction in the cost of owning a vehicle, whose full benefits consumers 

realize. This approach assumes that, regardless how consumers in fact make their decisions 

on how much fuel economy to purchase, they will gain these fuel savings. Another view says 

that consumers do not necessarily value fuel savings as equal to the results of this calculation. 

Instead, consumers may either undervalue or overvalue fuel economy relative to these 

savings, based on their personal preferences. This issue is discussed further in Section 8.1.2 

of this draft RIA. 

If we limit the analysis to the five model years 2012-2016—in other words, the fuel 

consumption savings during the lifetimes of those five model years, the results would be as 

shown in Table 6-17. 

Table 6-17 Annual Fuel Savings for 2012-2016 MY Vehicles Using Pre-tax Fuel Prices ($Millions of 2007 

dollars) 

YEAR 2012MY 2013MY 2014MY 2015MY 2016MY SUM 

2012 $1,300 $1,300 

2013 $1,300 $2,100 $3,500 

2014 $1,400 $2,200 $3,100 $6,700 

2015 $1,400 $2,200 $3,200 $4,600 $11,500 

2016 $1,400 $2,200 $3,200 $4,700 $6,500 $18,100 

2017 $1,400 $2,200 $3,200 $4,700 $6,600 $18,100 

2018 $1,400 $2,200 $3,200 $4,700 $6,600 $18,000 

2019 $1,300 $2,100 $3,100 $4,600 $6,500 $17,600 

2020 $1,200 $2,000 $3,000 $4,400 $6,300 $17,000 

2021 $1,100 $1,900 $2,800 $4,200 $6,000 $16,100 

2022 $1,100 $1,700 $2,600 $4,000 $5,700 $15,100 

2023 $900 $1,600 $2,400 $3,700 $5,400 $14,100 

2024 $800 $1,400 $2,200 $3,400 $5,000 $12,800 

2025 $600 $1,200 $2,000 $3,100 $4,600 $11,500 

2026 $500 $1,000 $1,700 $2,800 $4,200 $10,200 

2027 $400 $800 $1,400 $2,300 $3,700 $8,700 

2028 $300 $700 $1,100 $2,000 $3,200 $7,300 

2029 $300 $600 $1,000 $1,700 $2,700 $6,200 

2030 $200 $400 $800 $1,300 $2,200 $5,000 

2031 $200 $300 $600 $1,100 $1,800 $4,000 

2032 $100 $300 $500 $900 $1,500 $3,300 

2033 $100 $200 $400 $700 $1,200 $2,600 

2034 $100 $200 $300 $600 $1,000 $2,100 

2035 $100 $200 $300 $500 $800 $1,700 

2036 $100 $100 $200 $400 $600 $1,400 

2037 $100 $100 $200 $300 $500 $1,200 

2038 $0 $100 $200 $300 $400 $1,000 

2039 $0 $100 $100 $200 $400 $800 

2040 $0 $100 $100 $200 $300 $700 

2041 $0 $0 $100 $100 $300 $600 

2042 $0 $0 $100 $100 $200 $500 

2043 $0 $0 $100 $100 $200 $400 
Vehicle Program Costs Including Fuel Consumption Impacts 

6-15 

2044 $0 $0 $100 $100 $100 $300 

2045 $0 $0 $100 $100 $100 $300 

2046 $0 $0 $0 $100 $100 $300 

2047 $0 $0 $0 $100 $100 $200 

2048 $0 $0 $0 $100 $100 $200 

2049 $0 $0 $0 $0 $100 $200 

2050 $0 $0 $0 $0 $100 $100 

NPV, 3% $15,600 $24,400 $34,800 $49,800 $68,500 $193,100 

NPV, 7% $12,100 $19,000 $27,200 $38,900 $53,700 $150,900 

6.4 Vehicle Program Cost Summary 

The vehicle program costs consist of the vehicle compliance costs and the fuel savings 

(fuel savings are expressed here as negative fuel costs) that would result from the reduction in 

fuel consumption. These costs are summarized in Table 6-18. 

Table 6-18 Annual Vehicle Program Costs Including Fuel Costs Using Post-Tax Fuel Prices ($Millions of 

2007 dollars) 

YEAR 

VEHICLE 

COMPLIANCE 

COSTS 

FUEL COSTS 

(NEGATIVE COSTS 

ARE SAVINGS) 

TOTAL COSTS 

(NEGATIVE COSTS 

ARE SAVINGS) 

2012 $5,400 -$1,400 $4,000

2013 $8,400 -$3,800 $4,600

2014 $10,900 -$7,200 $3,700

2015 $13,900 -$12,400 $1,500

2016 $17,500 -$19,400 -$1,900

2017 $17,600 -$26,700 -$9,100

2018 $17,700 -$34,100 -$16,400

2019 $17,900 -$41,300 -$23,400

2020 $18,000 -$48,400 -$30,400

2021 $17,900 -$54,600 -$36,700

2022 $16,400 -$60,800 -$44,400

2023 $16,600 -$66,700 -$50,100

2024 $16,900 -$72,000 -$55,100

2025 $17,200 -$76,800 -$59,600

2026 $17,400 -$82,200 -$64,800

2027 $17,500 -$86,500 -$69,000

2028 $17,600 -$91,600 -$74,000

2029 $17,700 -$97,800 -$80,100

2030 $17,900 -$100,000 -$82,100

2031 $18,100 -$103,800 -$85,700

2032 $18,200 -$107,500 -$89,300

2033 $18,300 -$111,100 -$92,800

2034 $18,500 -$114,700 -$96,200

2035 $18,600 -$118,300 -$99,700

2036 $18,800 -$121,900 -$103,100

2037 $18,900 -$125,500 -$106,600

2038 $19,000 -$129,200 -$110,200

2039 $19,200 -$133,000 -$113,800
Regulatory Impact Analysis 

6-16 

2040 $19,300 -$136,800 -$117,500

2041 $19,500 -$140,700 -$121,200

2042 $19,600 -$144,700 -$125,100

2043 $19,800 -$148,800 -$129,000

2044 $19,900 -$153,100 -$133,200

2045 $20,100 -$157,400 -$137,300

2046 $20,200 -$161,900 -$141,700

2047 $20,400 -$166,500 -$146,100

2048 $20,500 -$171,200 -$150,700

2049 $20,700 -$176,100 -$155,400

2050 $20,900 -$181,000 -$160,100

NPV, 3% $390,000 -$1,850,200 -$1,460,200

NPV, 7% $216,600 -$826,900 -$610,300
Vehicle Program Costs Including Fuel Consumption Impacts 

6-17 

References

All references can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472. 

 1

 U.S. EPA. Baseline and Reference Fleet File, as documented in TSD chapter 1. August 2009. 

2

 US EPA 2009. Cost effective achieved levels spreadsheet. 

Environmental and Health Impacts 

7-1 

CHAPTER 7:Environmental and Health Impacts 

7.1 Health and Environmental Effects of Non-GHG Pollutants 

7.1.1 Health Effects Associated with Exposure to Pollutants 

 In this section we will discuss the health effects associated with non-GHG pollutants, 

specifically: particulate matter, ozone, nitrogen oxides (NOX), sulfur oxides (SOX), carbon 

monoxide and air toxics. These pollutants would not be directly regulated by the proposed 

standards, but the proposed standards would affect emissions of these pollutants and 

precursors. Reductions in these pollutants would be co-benefits of this proposal (that is, 

benefits in addition to the benefits of reduced GHGs). 

7.1.1.1 Particulate Matter 

7.1.1.1.1 Background 

 Particulate matter (PM) is a generic term for a broad class of chemically and 

physically diverse substances. It can be principally characterized as discrete particles that 

exist in the condensed (liquid or solid) phase spanning several orders of magnitude in size. 

Since 1987, EPA has delineated that subset of inhalable particles small enough to penetrate to 

the thoracic region (including the tracheobronchial and alveolar regions) of the respiratory 

tract (referred to as thoracic particles). Current national ambient air quality standards 

(NAAQS) use PM2.5 as the indicator for fine particles (with PM2.5 referring to particles with a 

nominal mean aerodynamic diameter less than or equal to 2.5 μm), and use PM10 as the 

indicator for purposes of regulating the coarse fraction of PM10 (referred to as thoracic coarse 

particles or coarse-fraction particles; generally including particles with a nominal mean 

aerodynamic diameter greater than 2.5 μm and less than or equal to 10 μm, or PM10-2.5). 

Ultrafine particles are a subset of fine particles, generally less than 100 nanometers (0.1 μm) 

in aerodynamic diameter. 

Particles span many sizes and shapes and consist of hundreds of different chemicals. 

Particles originate from sources and are also formed through atmospheric chemical reactions; 

the former are often referred to as “primary” particles, and the latter as “secondary” particles. 

In addition, there are also physical, non-chemical reaction mechanisms that contribute to 

secondary particles. Particle pollution also varies by time of year and location and is affected 

by several weather-related factors, such as temperature, clouds, humidity, and wind. A 

further layer of complexity comes from a particle’s ability to shift between solid/liquid and 

gaseous phases, which is influenced by concentration, meteorology, and temperature. 

Fine particles are produced primarily by combustion processes and by transformations 

of gaseous emissions (e.g., SOX, NOX and VOCs) in the atmosphere. The chemical and 

physical properties of PM2.5 may vary greatly with time, region, meteorology and source 

category. Thus, PM2.5 may include a complex mixture of different pollutants including 

sulfates, nitrates, organic compounds, elemental carbon and metal compounds. These 

particles can remain in the atmosphere for days to weeks and travel through the atmosphere 

hundreds to thousands of kilometers.1

 
Draft Regulatory Impact Analysis 

7-2 

7.1.1.1.2 Health Effects of PM 

 This section provides a summary of the health effects associated with exposure to 

ambient concentrations of PM.A The information in this section is based on the data and 

conclusions in the PM Air Quality Criteria Document (PM AQCD) and PM Staff Paper 

prepared by the U.S. Environmental Protection Agency (EPA).B,2,3 We also present 

additional recent studies published after the cut-off date for the PM AQCD.4,C

 Taken together 

this information supports the conclusion that exposure to ambient concentrations of PM are 

associated with adverse health effects. 

7.1.1.1.2.1 Short-term Exposure Mortality and Morbidity Studies 

 As discussed in the PM AQCD, short-term exposure to PM2.5 is associated with 

premature mortality from cardiopulmonary diseases,5

 hospitalization and emergency 

department visits for cardiopulmonary diseases,6

 increased respiratory symptoms,7 decreased 

lung function8

 and physiological changes or biomarkers for cardiac changes.9,10 In addition, 

the PM AQCD described a limited body of new evidence from epidemiologic studies for 

potential relationships between short term exposure to PM and health endpoints such as low 

birth weight, preterm birth, and neonatal and infant mortality.11 

Among the studies of effects associated with short-term exposure to PM2.5, several 

specifically address the contribution of mobile sources to short-term PM2.5-related effects on 

premature mortality. The results from these studies generally indicated that several 

combustion-related fine particle source-types are likely associated with mortality, including 

 A Personal exposure includes contributions from many different types of particles, from many sources, and in 

many different environments. Total personal exposure to PM includes both ambient and nonambient 

components; and both components may contribute to adverse health effects. 

B

 The PM NAAQS is currently under review and the EPA is considering all available science on PM health 

effects, including information which has been published since 2004, in the development of the upcoming PM 

Integrated Science Assessment Document (ISA). A second draft of the PM ISA was completed in July 2009 and 

was submitted for review by the Clean Air Scientific Advisory Committee (CASAC) of EPA’s Science Advisory 

Board. Comments from the general public have also been requested. For more information, see 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=210586. C

 These additional studies are included in the 2006 Provisional Assessment of Recent Studies on Health Effects 

of Particulate Matter Exposure. The provisional assessment did not and could not (given a very short timeframe) 

undergo the extensive critical review by CASAC and the public, as did the PM AQCD. The provisional 

assessment found that the “new” studies expand the scientific information and provide important insights on the 

relationship between PM exposure and health effects of PM. The provisional assessment also found that “new” 

studies generally strengthen the evidence that acute and chronic exposure to fine particles and acute exposure to 

thoracic coarse particles are associated with health effects. Further, the provisional science assessment found 

that the results reported in the studies did not dramatically diverge from previous findings, and taken in context 

with the findings of the AQCD, the new information and findings did not materially change any of the broad 

scientific conclusions regarding the health effects of PM exposure made in the AQCD. However, it is important 

to note that this assessment was limited to screening, surveying, and preparing a provisional assessment of these 

studies. For reasons outlined in Section I.C of the preamble for the final PM NAAQS rulemaking in 2006 (see 

71 FR 61148-49, October 17, 2006), EPA based its NAAQS decision on the science presented in the 2004 

AQCD. 
Environmental and Health Impacts 

7-3 

motor vehicle emissions as well as other sources.12 The analyses incorporate source 

apportionment tools into short-term exposure studies and are briefly mentioned here. 

Analyses incorporating source apportionment by factor analysis with daily time-series studies 

of daily death rates indicated a relationship between mobile source PM2.5 and 

mortality.13,14,15,16 Another recent study in 14 U.S. cities examined the effect of PM10

exposures on daily hospital admissions for cardiovascular disease. This study found that the 

effect of PM10 was significantly greater in areas with a larger proportion of PM10 coming from 

motor vehicles, indicating that PM10 from these sources may have a greater effect on the 

toxicity of ambient PM10 when compared with other sources.17 These studies provide 

evidence that PM-related emissions, specifically from mobile sources, are associated with 

adverse health effects. 

7.1.1.1.2.2 Long-term Exposure Mortality and Morbidity Studies 

 Long-term exposure to ambient PM2.5 is associated with premature mortality from 

cardiopulmonary diseases and lung cancer,18 and effects on the respiratory system such as 

decreased lung function or the development of chronic respiratory disease.19 Of specific 

importance, the PM AQCD also noted that the PM components of gasoline and diesel engine 

exhaust represent one class of hypothesized likely important contributors to the observed 

ambient PM-related increases in lung cancer incidence and mortality.20

The PM AQCD and PM Staff Paper emphasized the results of two long-term 

epidemiologic studies, the Six Cities and American Cancer Society (ACS) prospective cohort 

studies, based on several factors – the large air quality data set for PM in the Six Cities Study, 

the fact that the study populations were similar to the general population, and the fact that 

these studies have undergone extensive reanalysis.21,22,23,2425,26 These studies indicate that 

there are positive associations for all-cause, cardiopulmonary, and lung cancer mortality with 

long-term exposure to PM2.5. One analysis of a subset of the ACS cohort data, which was 

published after the PM AQCD was finalized but in time for the 2006 Provisional Assessment, 

found a larger association than had previously been reported between long-term PM2.5 

exposure and mortality in the Los Angeles area using a new exposure estimation method that 

accounted for variations in concentration within the city.27

As discussed in the PM AQCD, the morbidity studies that combine the features of 

cross-sectional and cohort studies provide the best evidence for chronic exposure effects. 

Long-term studies evaluating the effect of ambient PM on children’s development have 

shown some evidence indicating effects of PM2.5 and/or PM10 on reduced lung function 

growth.28 In another recent publication included in the 2006 Provisional Assessment, 

investigators in southern California reported the results of a cross-sectional study of outdoor 

PM2.5 and a measure of atherosclerosis development in the Los Angeles basin.29 The study 

found significant associations between ambient residential PM2.5 and carotid intima-media 

thickness (CIMT), an indicator of subclinical atherosclerosis, an underlying factor in 

cardiovascular disease. 

7.1.1.2 Ozone 

7.1.1.2.1 Background 
Draft Regulatory Impact Analysis 

7-4 

 Ground-level ozone pollution is typically formed by the reaction of VOCs and NOX

in the lower atmosphere in the presence of heat and sunlight. These pollutants, often referred 

to as ozone precursors, are emitted by many types of pollution sources such as highway and 

nonroad motor vehicles and engines, power plants, chemical plants, refineries, makers of 

consumer and commercial products, industrial facilities, and smaller area sources. 

The science of ozone formation, transport, and accumulation is complex. Groundlevel ozone is produced and destroyed in a cyclical set of chemical reactions, many of which 

are sensitive to temperature and sunlight. When ambient temperatures and sunlight levels 

remain high for several days and the air is relatively stagnant, ozone and its precursors can 

build up and result in more ozone than typically occurs on a single high-temperature day. 

Ozone can be transported hundreds of miles downwind of precursor emissions, resulting in 

elevated ozone levels even in areas with low VOC or NOX emissions. 

The highest levels of ozone are produced when both VOC and NOX emissions are 

present in significant quantities on clear summer days. Relatively small amounts of NOX

enable ozone to form rapidly when VOC levels are relatively high, but ozone production is 

quickly limited by removal of the NOX. Under these conditions NOX reductions are highly 

effective in reducing ozone while VOC reductions have little effect. Such conditions are 

called “NOX-limited.” Because the contribution of VOC emissions from biogenic (natural) 

sources to local ambient ozone concentrations can be significant, even some areas where manmade VOC emissions are relatively low can be NOX-limited. 

Ozone concentrations in an area also can be lowered by the reaction of nitric oxide 

(NO) with ozone, forming nitrogen dioxide (NO2); as the air moves downwind and the cycle 

continues, the NO2 forms additional ozone. The importance of this reaction depends, in part, 

on the relative concentrations of NOX, VOC, and ozone, all of which change with time and 

location. When NOX levels are relatively high and VOC levels relatively low, NOX forms 

inorganic nitrates (i.e., particles) but relatively little ozone. Such conditions are called “VOClimited”. Under these conditions, VOC reductions are effective in reducing ozone, but NOX

reductions can actually increase local ozone under certain circumstances. Even in VOClimited urban areas, NOX reductions are not expected to increase ozone levels if the NOX

reductions are sufficiently large. 

Rural areas are usually NOX-limited, due to the relatively large amounts of biogenic 

VOC emissions in such areas. Urban areas can be either VOC- or NOX-limited, or a mixture 

of both, in which ozone levels exhibit moderate sensitivity to changes in either pollutant. 

7.1.1.2.2 Health Effects of Ozone 

 Exposure to ambient ozone contributes to a wide range of adverse health effects.D 

These health effects are well documented and are critically assessed in the EPA ozone air 

quality criteria document (ozone AQCD) and EPA staff paper.30,31 We are relying on the data 

 D Human exposure to ozone varies over time due to changes in ambient ozone concentration and because people 

move between locations which have notable different ozone concentrations. Also, the amount of ozone 

delivered to the lung is not only influenced by the ambient concentrations but also by the individuals breathing 

route and rate. 
Environmental and Health Impacts 

7-5 

and conclusions in the ozone AQCD and staff paper, regarding the health effects associated 

with ozone exposure. 

Ozone-related health effects include lung function decrements, respiratory symptoms, 

aggravation of asthma, increased hospital and emergency room visits, increased asthma 

medication usage, and a variety of other respiratory effects. Cellular-level effects, such as 

inflammation of lungs, have been documented as well. In addition, there is suggestive 

evidence of a contribution of ozone to cardiovascular-related morbidity and highly suggestive 

evidence that short-term ozone exposure directly or indirectly contributes to non-accidental 

and cardiopulmonary-related mortality, but additional research is needed to clarify the 

underlying mechanisms causing these effects. In a recent report on the estimation of ozonerelated premature mortality published by the National Research Council (NRC), a panel of 

experts and reviewers concluded that short-term exposure to ambient ozone is likely to 

contribute to premature deaths and that ozone-related mortality should be included in 

estimates of the health benefits of reducing ozone exposure.32 People who are more 

susceptible to effects associated with exposure to ozone can include children, asthmatics and 

the elderly. Those with greater exposures to ozone, for instance due to time spent outdoors 

(e.g., children and outdoor workers), are also of concern. 

Based on a large number of scientific studies, EPA has identified several key health 

effects associated with exposure to levels of ozone found today in many areas of the country. 

Short-term (1 to 3 hours) and prolonged exposures (6 to 8 hours) to ambient ozone 

concentrations have been linked to lung function decrements, respiratory symptoms, increased 

hospital admissions and emergency room visits for respiratory problems.33, 34, 35, 36, 37, 38 

Repeated exposure to ozone can increase susceptibility to respiratory infection and lung 

inflammation and can aggravate preexisting respiratory diseases, such as asthma.39, 40, 41, 42, 43

Repeated exposure to sufficient concentrations of ozone can also cause inflammation of the 

lung, impairment of lung defense mechanisms, and possibly irreversible changes in lung 

structure, which over time could affect premature aging of the lungs and/or the development 

of chronic respiratory illnesses, such as emphysema and chronic bronchitis.44, 45, 46, 47 

Children and adults who are outdoors and active during the summer months, such as 

construction workers, are among those most at risk of elevated ozone exposures.48 Children 

and outdoor workers tend to have higher ozone exposure because they typically are active 

outside, working, playing and exercising, during times of day and seasons (e.g., the summer) 

when ozone levels are highest.49 For example, summer camp studies in the Eastern United 

States and Southeastern Canada have reported statistically significant reductions in lung 

function in children who are active outdoors.50, 51, 52, 53, 54, 55, 56, 57 Further, children are more at 

risk of experiencing health effects from ozone exposure than adults because their respiratory 

systems are still developing. These individuals (as well as people with respiratory illnesses, 

such as asthma, especially asthmatic children) can experience reduced lung function and 

increased respiratory symptoms, such as chest pain and cough, when exposed to relatively low 

ozone levels during prolonged periods of moderate exertion.58, 59, 60, 61
Draft Regulatory Impact Analysis 

7-6 

7.1.1.3 Nitrogen Oxides and Sulfur Oxides 

7.1.1.3.1 Background 

 Sulfur dioxide (SO2), a member of the sulfur oxide (SOX) family of gases, is formed 

from burning fuels containing sulfur (e.g., coal or oil derived), extracting gasoline from oil, or 

extracting metals from ore. Nitrogen dioxide (NO2) is a member of the nitrogen oxide (NOX) 

family of gases. Most NO2 is formed in the air through the oxidation of nitric oxide (NO) 

emitted when fuel is burned at a high temperature. 

 SO2 andNO2 can dissolve in water vapor and further oxidize to form sulfuric and 

nitric acid which react with ammonia to form sulfates and nitrates, both of which are 

important components of ambient PM. The health effects of ambient PM are discussed in 

Section 7.1.1.1.2. NOX along with non-methane hydrocarbons (NMHC) are the two major 

precursors of ozone. The health effects of ozone are covered in Section 7.1.1.2.2. 

7.1.1.3.2 Health Effects of Sulfur Oxides 

Information on the health effects of SO2 can be found in the U.S. Environmental 

Protection Agency Integrated Science Assessment for Sulfur Oxides.62 SO2 has long been 

known to cause adverse respiratory health effects, particularly among individuals with 

asthma. Other potentially sensitive groups include children and the elderly. During periods of 

elevated ventilation, asthmatics may experience symptomatic bronchoconstriction within 

minutes of exposure. Following an extensive evaluation of health evidence from 

epidemiologic and laboratory studies, the EPA has concluded that there is a causal 

relationship between respiratory health effects and short-term exposure to SO2. Separately, 

based on an evaluation of the epidemiologic evidence of associations between short-term 

exposure to SO2 and mortality, the EPA has concluded that the overall evidence is suggestive 

of a causal relationship between short-term exposure to SO2 and mortality. 

7.1.1.3.3 Health Effects of Nitrogen Oxides 

Information on the health effects of NO2 can be found in the U.S. Environmental 

Protection Agency Integrated Science Assessment (ISA) for Nitrogen Oxides.63 The U.S. 

EPA has concluded that the findings of epidemiologic, controlled human exposure, and 

animal toxicological studies provide evidence that is sufficient to infer a likely causal 

relationship between respiratory effects and short-term NO2 exposure. The ISA concludes 

that the strongest evidence for such a relationship comes from epidemiologic studies of 

respiratory effects including symptoms, emergency department visits, and hospital 

admissions. The ISA also draws two broad conclusions regarding airway responsiveness 

following NO2 exposure. First, the ISA concludes that NO2 exposure may enhance the 

sensitivity to allergen-induced decrements in lung function and increase the allergen-induced 

airway inflammatory response at exposures as low as 0.26 ppm NO2 for 30 minutes. Second, 

exposure to NO2 has been found to enhance the inherent responsiveness of the airway to 

subsequent nonspecific challenges in controlled human exposure studies of asthmatic 
Environmental and Health Impacts 

7-7 

subjects. Enhanced airway responsiveness could have important clinical implications for 

asthmatics since transient increases in airway responsiveness following NO2 exposure have 

the potential to increase symptoms and worsen asthma control. Together, the epidemiologic 

and experimental data sets form a plausible, consistent, and coherent description of a 

relationship between NO2 exposures and an array of adverse health effects that range from the 

onset of respiratory symptoms to hospital admission. 

Although the weight of evidence supporting a causal relationship is somewhat less 

certain than that associated with respiratory morbidity, NO2 has also been linked to other 

health endpoints. These include all-cause (nonaccidental) mortality, hospital admissions or 

emergency department visits for cardiovascular disease, and decrements in lung function 

growth associated with chronic exposure. 

7.1.1.4 Carbon Monoxide 

 We are relying on the data and conclusions in the EPA Air Quality Criteria Document 

for CO (CO Criteria Document), which was published in 2000, regarding the health effects 

associated with CO exposure.E,64 Carbon monoxide enters the bloodstream through the lungs 

and forms carboxyhemoglobin (COHb), a compound that inhibits the blood’s capacity to 

carry oxygen to organs and tissues.65,66 Carbon monoxide has long been known to have 

substantial adverse effects on human health, including toxic effects on blood and tissues, and 

effects on organ functions. Although there are effective compensatory increases in blood 

flow to the brain, at some concentrations of COHb somewhere above 20 percent, these 

compensations fail to maintain sufficient oxygen delivery, and metabolism declines.67 The 

subsequent hypoxia in brain tissue then produces behavioral effects, including decrements in 

continuous performance and reaction time.68

Carbon monoxide has been linked to increased risk for people with heart disease, 

reduced visual perception, cognitive functions and aerobic capacity, and possible fetal 

effects.69 Persons with heart disease are especially sensitive to CO poisoning and may 

experience chest pain if they breathe the gas while exercising.70 Infants, elderly persons, and 

individuals with respiratory diseases are also particularly sensitive. Carbon monoxide can 

affect healthy individuals, impairing exercise capacity, visual perception, manual dexterity, 

learning functions, and ability to perform complex tasks.71

Several epidemiological studies have shown a link between CO and premature 

morbidity (including angina, congestive heart failure, and other cardiovascular diseases). 

Several studies in the United States and Canada have also reported an association between 

ambient CO exposures and frequency of cardiovascular hospital admissions, especially for 

congestive heart failure (CHF). An association between ambient CO exposure and mortality 

has also been reported in epidemiological studies, though not as consistently or specifically as 

with CHF admissions. EPA reviewed these studies as part of the CO Criteria Document 

 E

 The CO NAAQS is currently under review and the EPA is considering all available science on CO health 

effects, including information which has been published since 2000, in the development of the upcoming CO 

Integrated Science Assessment Document (ISA). A first draft of the CO ISA was completed in March 2009 and 

was submitted for review by the Clean Air Scientific Advisory Committee (CASAC) of EPA’s Science Advisory 

Board. For more information, see http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=203935. 
Draft Regulatory Impact Analysis 

7-8 

review process and noted the possibility that the average ambient CO levels used as exposure 

indices in the epidemiology studies may be surrogates for ambient air mixes impacted by 

combustion sources and/or other constituent toxic components of such mixes. More research 

will be needed to better clarify CO’s role.72 

7.1.1.5 Air Toxics 

Motor vehicle emissions contribute to ambient levels of air toxics known or suspected 

as human or animal carcinogens, or that have noncancer health effects. The population 

experiences an elevated risk of cancer and other noncancer health effects from exposure to air 

toxics.73 These compounds include, but are not limited to, benzene, 1,3-butadiene, 

formaldehyde, acetaldehyde, acrolein, polycyclic organic matter (POM), and naphthalene. 

These compounds, except acetaldehyde, were identified as national or regional risk drivers in 

the 2002 National-scale Air Toxics Assessment (NATA) and have significant inventory 

contributions from mobile sources. 

Table 7-1 Mobile Source Inventory Contribution to 2002 Emissions of NATA Risk Driversa 

 2002 NATA Risk Driver Percent of National 

Emissions Attributable 

to All Mobile Sources 

Percent of National 

Emissions Attributable 

to Light-Duty Vehicles 

Benzene 59% 41% 

1,3-Butadiene 58% 37% 

Formaldehyde 43% 19% 

Acrolein 18% 9% 

Polycyclic organic matter (POM)b 6% 3% 

Naphthalene 35% 22% 

Diesel PM and Diesel exhaust 

organic gases 

100% 1% 

a

 This table is generated from data contained in the pollutant specific Microsoft Access database files found 

in the State-Specific Emission by County section of the 2002 NATA webpage 

(http://www.epa.gov/ttn/atw/nata2002/tables.html) and data from the 2002 National Emissions Inventory 

(NEI; http://www.epa.gov/ttn/chief/net/2002inventory.html), which is the underlying basis for the emissions 

used in the 2002 NATA (http://www.epa.gov/ttn/atw/nata2002/methods.html). 

b This POM inventory includes the 15 POM compounds: benzo[b]fluoranthene, benz[a]anthracene, indeno(1,2,3-

c,d)pyrene, benzo[k]fluoranthene, chrysene, benzo[a]pyrene, dibenz(a,h)anthracene, anthracene, pyrene, 

benzo(g,h,i)perylene, fluoranthene, acenaphthylene, phenanthrene, fluorine, and acenaphthene. 

According to NATA for 2002, mobile sources were responsible for 47 percent of 

outdoor toxic emissions, over 50 percent of the cancer risk, and over 80 percent of the 

noncancer hazard. Benzene is the largest contributor to cancer risk of all 124 pollutants 

quantitatively assessed in the 2002 NATA and mobile sources were responsible for 59 percent 

of benzene emissions in 2002. In 2007, EPA finalized vehicle and fuel controls that address 

this public health risk; it will reduce total emissions of mobile source air toxics by 330,000 

tons in 2030, including 61,000 tons of benzene. 74
Environmental and Health Impacts 

7-9 

Noncancer health effects can result from chronic,F

 subchronic,G or acuteH inhalation 

exposures to air toxics, and include neurological, cardiovascular, liver, kidney, and respiratory 

effects as well as effects on the immune and reproductive systems. According to the 2002 

NATA, nearly the entire U.S. population was exposed to an average concentration of air 

toxics that has the potential for adverse noncancer respiratory health effects. This will 

continue to be the case in 2030, even though toxics concentrations will be lower. Mobile 

sources were responsible for over 80 percent of the noncancer (respiratory) risk from outdoor 

air toxics in 2002. The majority of this risk was from exposure to acrolein. The confidence in 

the RfC for acrolein is medium and confidence in NATA estimates of population noncancer 

hazard from ambient exposure to this pollutant is low.75,76

The NATA modeling framework has a number of limitations which prevent its use as 

the sole basis for setting regulatory standards. These limitations and uncertainties are 

discussed on the 2002 NATA website.77 Even so, this modeling framework is very useful in 

identifying air toxic pollutants and sources of greatest concern, setting regulatory priorities, 

and informing the decision making process. 

7.1.1.5.1 Benzene 

 The EPA’s IRIS database lists benzene as a known human carcinogen (causing 

leukemia) by all routes of exposure, and concludes that exposure is associated with additional 

health effects, including genetic changes in both humans and animals and increased 

proliferation of bone marrow cells in mice.78,79,80 EPA states in its IRIS database that data 

indicate a causal relationship between benzene exposure and acute lymphocytic leukemia and 

suggest a relationship between benzene exposure and chronic non-lymphocytic leukemia and 

chronic lymphocytic leukemia. The International Agency for Research on Carcinogens 

(IARC) has determined that benzene is a human carcinogen and the U.S. Department of 

Health and Human Services (DHHS) has characterized benzene as a known human 

carcinogen.81,82

A number of adverse noncancer health effects including blood disorders, such as 

preleukemia and aplastic anemia, have also been associated with long-term exposure to 

benzene.83,84 The most sensitive noncancer effect observed in humans, based on current data, 

is the depression of the absolute lymphocyte count in blood.85,86 In addition, recent work, 

including studies sponsored by the Health Effects Institute (HEI), provides evidence that 

biochemical responses are occurring at lower levels of benzene exposure than previously 

known.87,88,89,90 EPA’s IRIS program has not yet evaluated these new data. 

7.1.1.5.2 1,3-Butadiene 

 F

 Chronic exposure is defined in the glossary of the Integrated Risk Information (IRIS) database 

(http://www.epa.gov/iris) as repeated exposure by the oral, dermal, or inhalation route for more than 

approximately 10% of the life span in humans (more than approximately 90 days to 2 years in typically used 

laboratory animal species). 

G Defined in the IRIS database as exposure to a substance spanning approximately 10% of the lifetime of an 

organism. 

H Defined in the IRIS database as exposure by the oral, dermal, or inhalation route for 24 hours or less. 
Draft Regulatory Impact Analysis 

7-10 

 EPA has characterized 1,3-butadiene as carcinogenic to humans by inhalation.91,92 

The IARC has determined that 1,3-butadiene is a human carcinogen and the U.S. DHHS has 

characterized 1,3-butadiene as a known human carcinogen.93,94 There are numerous studies 

consistently demonstrating that 1,3-butadiene is metabolized into genotoxic metabolites by 

experimental animals and humans. The specific mechanisms of 1,3-butadiene-induced 

carcinogenesis are unknown; however, the scientific evidence strongly suggests that the 

carcinogenic effects are mediated by genotoxic metabolites. Animal data suggest that females 

may be more sensitive than males for cancer effects associated with 1,3-butadiene exposure; 

there are insufficient data in humans from which to draw conclusions about sensitive 

subpopulations. 1,3-butadiene also causes a variety of reproductive and developmental 

effects in mice; no human data on these effects are available. The most sensitive effect was 

ovarian atrophy observed in a lifetime bioassay of female mice.95

7.1.1.5.3 Formaldehyde 

 Since 1987, EPA has classified formaldehyde as a probable human carcinogen based 

on evidence in humans and in rats, mice, hamsters, and monkeys.96 EPA is currently 

reviewing recently published epidemiological data. For instance, research conducted by the 

National Cancer Institute (NCI) found an increased risk of nasopharyngeal cancer and 

lymphohematopoietic malignancies such as leukemia among workers exposed to 

formaldehyde.97,98 In an analysis of the lymphohematopoietic cancer mortality from an 

extended follow-up of these workers, NCI confirmed an association between 

lymphohematopoietic cancer risk and peak exposures.99 A recent National Institute of 

Occupational Safety and Health (NIOSH) study of garment workers also found increased risk 

of death due to leukemia among workers exposed to formaldehyde.100 Extended follow-up of 

a cohort of British chemical workers did not find evidence of an increase in nasopharyngeal or 

lymphohematopoietic cancers, but a continuing statistically significant excess in lung cancers 

was reported.101

In the past 15 years there has been substantial research on the inhalation dosimetry for 

formaldehyde in rodents and primates by the CIIT Centers for Health Research (formerly the 

Chemical Industry Institute of Toxicology), with a focus on use of rodent data for refinement 

of the quantitative cancer dose-response assessment.102,103,104 CIIT’s risk assessment of 

formaldehyde incorporated mechanistic and dosimetric information on formaldehyde. 

However, it should be noted that recent research published by EPA indicates that when twostage modeling assumptions are varied, resulting dose-response estimates can vary by several 

orders of magnitude.105,106,107,108 These findings are not supportive of interpreting the CIIT 

model results as providing a conservative (health protective) estimate of human risk. EPA 

research also examined the contribution of the two-stage modeling for formaldehyde towards 

characterizing the relative weights of key events in the mode-of-action of a carcinogen. For 

example, the model-based inference in the published CIIT study that formaldehyde’s direct 

mutagenic action is not relevant to the compound’s tumorigenicity was found not to hold 

under variations of modeling assumptions. 

Based on the developments of the last decade, in 2004, the working group of the IARC 

concluded that formaldehyde is carcinogenic to humans (Group 1), on the basis of sufficient 

evidence in humans and sufficient evidence in experimental animals - a higher classification 
Environmental and Health Impacts 

7-11 

than previous IARC evaluations. After reviewing the currently available epidemiological 

evidence, the IARC (2006) characterized the human evidence for formaldehyde 

carcinogenicity as “sufficient,” based upon the data on nasopharyngeal cancers; the 

epidemiologic evidence on leukemia was characterized as “strong.”109 EPA is reviewing the 

recent work cited above from the NCI and NIOSH, as well as the analysis by the CIIT Centers 

for Health Research and other studies, as part of a reassessment of the human hazard and 

dose-response associated with formaldehyde. 

Formaldehyde exposure also causes a range of noncancer health effects, including 

irritation of the eyes (burning and watering of the eyes), nose and throat. Effects from 

repeated exposure in humans include respiratory tract irritation, chronic bronchitis and nasal 

epithelial lesions such as metaplasia and loss of cilia. Animal studies suggest that 

formaldehyde may also cause airway inflammation – including eosinophil infiltration into the 

airways. There are several studies that suggest that formaldehyde may increase the risk of 

asthma – particularly in the young.110,111

7.1.1.5.4 Acetaldehyde 

 Acetaldehyde is classified in EPA’s IRIS database as a probable human carcinogen, 

based on nasal tumors in rats, and is considered toxic by the inhalation, oral, and intravenous 

routes.112 Acetaldehyde is reasonably anticipated to be a human carcinogen by the U.S. 

DHHS in the 11th Report on Carcinogens and is classified as possibly carcinogenic to humans 

(Group 2B) by the IARC.113,114 EPA is currently conducting a reassessment of cancer risk 

from inhalation exposure to acetaldehyde. 

The primary noncancer effects of exposure to acetaldehyde vapors include irritation of 

the eyes, skin, and respiratory tract.115 In short-term (4 week) rat studies, degeneration of 

olfactory epithelium was observed at various concentration levels of acetaldehyde 

exposure.116,117 Data from these studies were used by EPA to develop an inhalation reference 

concentration. Some asthmatics have been shown to be a sensitive subpopulation to 

decrements in functional expiratory volume (FEV1 test) and bronchoconstriction upon 

acetaldehyde inhalation.118 The agency is currently conducting a reassessment of the health 

hazards from inhalation exposure to acetaldehyde. 

7.1.1.5.5 Acrolein 

 EPA determined in 2003 that the human carcinogenic potential of acrolein could not 

be determined because the available data were inadequate. No information was available on 

the carcinogenic effects of acrolein in humans and the animal data provided inadequate 

evidence of carcinogenicity.119 The IARC determined in 1995 that acrolein was not 

classifiable as to its carcinogenicity in humans.120

Acrolein is extremely acrid and irritating to humans when inhaled, with acute 

exposure resulting in upper respiratory tract irritation, mucus hypersecretion and congestion. 

Levels considerably lower than 1 ppm (2.3 mg/m3

) elicit subjective complaints of eye and 

nasal irritation and a decrease in the respiratory rate.121,122 Lesions to the lungs and upper 

respiratory tract of rats, rabbits, and hamsters have been observed after subchronic exposure 
Draft Regulatory Impact Analysis 

7-12 

to acrolein. Based on animal data, individuals with compromised respiratory function (e.g., 

emphysema, asthma) are expected to be at increased risk of developing adverse responses to 

strong respiratory irritants such as acrolein. This was demonstrated in mice with allergic 

airway-disease by comparison to non-diseased mice in a study of the acute respiratory irritant 

effects of acrolein.123

EPA is currently in the process of conducting an assessment of acute exposure effects 

for acrolein. The intense irritancy of this carbonyl has been demonstrated during controlled 

tests in human subjects, who suffer intolerable eye and nasal mucosal sensory reactions within 

minutes of exposure.124

7.1.1.5.6 Polycyclic Organic Matter (POM) 

 POM is generally defined as a large class of organic compounds which have multiple 

benzene rings and a boiling point greater than 100 degrees Celsius. Many of the compounds 

included in the class of compounds known as POM are classified by EPA as probable human 

carcinogens based on animal data. One of these compounds, naphthalene, is discussed 

separately below. Polycyclic aromatic hydrocarbons (PAHs) are a subset of POM that 

contain only hydrogen and carbon atoms. A number of PAHs are known or suspected 

carcinogens. Recent studies have found that maternal exposures to PAHs (a subclass of 

POM) in a population of pregnant women were associated with several adverse birth 

outcomes, including low birth weight and reduced length at birth, as well as impaired 

cognitive development at age three.125,126 EPA has not yet evaluated these recent studies. 

7.1.1.5.7 Naphthalene 

 Naphthalene is found in small quantities in gasoline and diesel fuels. Naphthalene 

emissions have been measured in larger quantities in both gasoline and diesel exhaust 

compared with evaporative emissions from mobile sources, indicating it is primarily a product 

of combustion. EPA released an external review draft of a reassessment of the inhalation 

carcinogenicity of naphthalene based on a number of recent animal carcinogenicity studies.127 

The draft reassessment completed external peer review.128 Based on external peer review 

comments received, additional analyses are being undertaken. This external review draft does 

not represent official agency opinion and was released solely for the purposes of external peer 

review and public comment. Once EPA evaluates public and peer reviewer comments, the 

document will be revised. The National Toxicology Program listed naphthalene as 

"reasonably anticipated to be a human carcinogen" in 2004 on the basis of bioassays reporting 

clear evidence of carcinogenicity in rats and some evidence of carcinogenicity in mice.129 

California EPA has released a new risk assessment for naphthalene, and the IARC has 

reevaluated naphthalene and re-classified it as Group 2B: possibly carcinogenic to humans.130 

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

abnormal cell changes and growth in respiratory and nasal tissues.131

7.1.1.5.8 Other Air Toxics 

 In addition to the compounds described above, other compounds in gaseous 

hydrocarbon and PM emissions from vehicles would be affected by today’s proposed action. 
Environmental and Health Impacts 

7-13 

Mobile source air toxic compounds that would potentially be impacted include ethylbenzene, 

polycyclic organic matter, propionaldehyde, toluene, and xylene. Information regarding the 

health effects of these compounds can be found in EPA’s IRIS database.132

7.1.2 Environmental Effects Associated with Exposure to Pollutants 

 In this section we will discuss the environmental effects associated with non-GHG copollutants, specifically: particulate matter, ozone, NOX, SOX, carbon monoxide and air toxics. 

7.1.2.1 Visibility Degradation 

 Emissions from LD vehicles contribute to poor visibility in the U.S. through their 

primary PM2.5 and NOX emissions (which contribute to the formation of secondary PM2.5). 

These airborne particles degrade visibility by scattering and absorbing light. Good visibility 

increases the quality of life where individuals live and work, and where they engage in 

recreational activities. 

The U.S. government places special emphasis on protecting visibility in national parks 

and wilderness areas. Section 169 of the Clean Air Act requires the U.S. government to 

address existing visibility impairment and future visibility impairment in the 156 national 

parks (see Figure 7-1) exceeding 6,000 acres, and wilderness areas exceeding 5,000 acres, 

which are categorized as mandatory class I federal areas (62 FR 38680, July 18, 1997). 

7.1.2.1.1 Visibility Monitoring 

 In conjunction with the U.S. National Park Service, the U.S. Forest Service, other 

Federal land managers, and State organizations in the U.S., the U.S. EPA has supported 

visibility monitoring in national parks and wilderness areas since 1988. The monitoring 

network was originally established at 20 sites, but it has now been expanded to 110 sites that 

represent all but one of the 156 mandatory Federal Class I areas across the country (see Figure 

7-1). This long-term visibility monitoring network is known as IMPROVE (Interagency 

Monitoring of Protected Visual Environments).

IMPROVE provides direct measurement of fine particles that contribute to visibility 

impairment. The IMPROVE network employs aerosol measurements at all sites, and optical 

and scene measurements at some of the sites. Aerosol measurements are taken for PM10 and 

PM2.5 mass, and for key constituents of PM2.5, such as sulfate, nitrate, organic and elemental 

carbon, soil dust, and several other elements. Measurements for specific aerosol constituents 

are used to calculate "reconstructed" aerosol light extinction by multiplying the mass for each 

constituent by its empirically-derived scattering and/or absorption efficiency, with adjustment 

for the relative humidity. Knowledge of the main constituents of a site's light extinction 

"budget" is critical for source apportionment and control strategy development. Optical 

measurements are used to directly measure light extinction or its components. Such 

measurements are taken principally with either a transmissometer, which measures total light 

extinction, or a nephelometer, which measures particle scattering (the largest human-caused 

component of total extinction). Scene characteristics are typically recorded three times daily 

with 35 millimeter photography and are used to determine the quality of visibility conditions 
Draft Regulatory Impact Analysis 

7-14 

(such as effects on color and contrast) associated with specific levels of light extinction as 

measured under both direct and aerosol-related methods. Directly measured light extinction 

is used under the IMPROVE protocol to cross check that the aerosol-derived light extinction 

levels are reasonable in establishing current visibility conditions. Aerosol-derived light 

extinction is used to document spatial and temporal trends and to determine how proposed 

changes in atmospheric constituents would affect future visibility conditions. 

Annual average visibility conditions (reflecting light extinction due to both 

anthropogenic and non-anthropogenic sources) vary regionally across the U.S. The rural East 

generally has higher levels of impairment than remote sites in the West, with the exception of 

urban-influenced sites such as San Gorgonio Wilderness (CA) and Point Reyes National 

Seashore (CA), which have annual average levels comparable to certain sites in the Northeast. 

Regional differences are illustrated by Figures 4-39a and 4-39b in the Air Quality Criteria 

Document for Particulate Matter, which show that, for Class I areas, visibility levels on the 

20% haziest days in the West are about equal to levels on the 20% best days in the East.133

Higher visibility impairment levels in the East are due to generally higher 

concentrations of anthropogenic fine particles, particularly sulfates, and higher average 

relative humidity levels. In fact, sulfates account for 60-86% of the haziness in eastern 

sites.134 Aerosol light extinction due to sulfate on the 20% haziest days is significantly larger 

in eastern Class I areas as compared to western areas (Figures 4-40a and 4-40b in the Air 

Quality Criteria Document for Particulate Matter).135 With the exception of remote sites in 

the northwestern U.S., visibility is typically worse in the summer months. This is particularly 

true in the Appalachian region, where average light extinction in the summer exceeds the 

annual average by 40%.136 

7.1.2.1.2 Addressing Visibility in the U.S. 

 The U.S. EPA is pursuing a two-part strategy to address visibility. First, to address 

the welfare effects of PM on visibility, EPA set secondary PM2.5 standards which act in 

conjunction with the establishment of a regional haze program. In setting this secondary 

standard, EPA has concluded that PM2.5 causes adverse effects on visibility in various 

locations, depending on PM concentrations and factors such as chemical composition and 

average relative humidity. Second, section 169 of the Clean Air Act provides additional 

authority to address existing visibility impairment and prevent future visibility impairment in 

the 156 national parks, forests and wilderness areas categorized as mandatory Class I federal 

areas (62 FR 38680-81, July 18, 1997).I

 Figure 7-1 below identifies where each of these 

parks are located in the U.S. In July 1999, the regional haze rule (64 FR 35714) was put in 

place to protect the visibility in mandatory Class I federal areas. Visibility can be said to be 

impaired in both PM2.5 nonattainment areas and mandatory Class I federal areas.J

 

 I

 These areas are defined in section 162 of the Act as those national parks exceeding 6,000 acres, wilderness 

areas and memorial parks exceeding 5,000 acres, and all international parks which were in existence on August 

7, 1977. 

J

 As mentioned above, the EPA recently amended the PM NAAQS, making the secondary NAAQS equal, in all 

respects, to the primary standards for both PM2.5 and PM10, (71 FR 61144, Oct. 17, 2006). In February 2009, the 

D.C. Circuit Court remanded the secondary standards for fine particles, based on EPA’s failure to adequately 
Environmental and Health Impacts 

7-15 

 

Figure 7-1 Mandatory Class I Areas in the U.S.

7.1.2.2 Plant and Ecosystem Effects of Ozone 

 There are a number of environmental or public welfare effects associated with the 

presence of ozone in the ambient air.137 In this section we discuss the impact of ozone on 

plants, including trees, agronomic crops and urban ornamentals. 

The Air Quality Criteria Document for Ozone and related Photochemical Oxidants 

notes that, “ozone affects vegetation throughout the United States, impairing crops, native 

vegetation, and ecosystems more than any other air pollutant”.138 Like carbon dioxide (CO2) 

and other gaseous substances, ozone enters plant tissues primarily through apertures (stomata) 

in leaves in a process called “uptake”.139 Once sufficient levels of ozone, a highly reactive 

substance, (or its reaction products) reaches the interior of plant cells, it can inhibit or damage 

essential cellular components and functions, including enzyme activities, lipids, and cellular 

membranes, disrupting the plant's osmotic (i.e., water) balance and energy utilization 

patterns.140,141 If enough tissue becomes damaged from these effects, a plant’s capacity to fix 

carbon to form carbohydrates, which are the primary form of energy used by plants is 

 explain why setting the secondary PM2.5 NAAQS equivalent to the primary standards provided the required 

protection for public welfare including protection from visibility impairment. 
Draft Regulatory Impact Analysis 

7-16 

reduced,142 while plant respiration increases. With fewer resources available, the plant 

reallocates existing resources away from root growth and storage, above ground growth or 

yield, and reproductive processes, toward leaf repair and maintenance, leading to reduced 

growth and/or reproduction. Studies have shown that plants stressed in these ways may 

exhibit a general loss of vigor, which can lead to secondary impacts that modify plants' 

responses to other environmental factors. Specifically, plants may become more sensitive to 

other air pollutants, more susceptible to disease, insect attack, harsh weather (e.g., drought, 

frost) and other environmental stresses. Furthermore, there is evidence that ozone can 

interfere with the formation of mycorrhiza, essential symbiotic fungi associated with the roots 

of most terrestrial plants, by reducing the amount of carbon available for transfer from the 

host to the symbiont.143,144 

This ozone damage may or may not be accompanied by visible injury on leaves, and 

likewise, visible foliar injury may or may not be a symptom of the other types of plant 

damage described above. When visible injury is present, it is commonly manifested as 

chlorotic or necrotic spots, and/or increased leaf senescence (accelerated leaf aging). Because 

ozone damage can consist of visible injury to leaves, it can also reduce the aesthetic value of 

ornamental vegetation and trees in urban landscapes, and negatively affects scenic vistas in 

protected natural areas. 

Ozone can produce both acute and chronic injury in sensitive species depending on the 

concentration level and the duration of the exposure. Ozone effects also tend to accumulate 

over the growing season of the plant, so that even lower concentrations experienced for a 

longer duration have the potential to create chronic stress on sensitive vegetation. Not all 

plants, however, are equally sensitive to ozone. Much of the variation in sensitivity between 

individual plants or whole species is related to the plant’s ability to regulate the extent of gas 

exchange via leaf stomata (e.g., avoidance of ozone uptake through closure of 

stomata)145,146,147 Other resistance mechanisms may involve the intercellular production of 

detoxifying substances. Several biochemical substances capable of detoxifying ozone have 

been reported to occur in plants, including the antioxidants ascorbate and glutathione. After 

injuries have occurred, plants may be capable of repairing the damage to a limited extent.148

Because of the differing sensitivities among plants to ozone, ozone pollution can also 

exert a selective pressure that leads to changes in plant community composition. Given the 

range of plant sensitivities and the fact that numerous other environmental factors modify 

plant uptake and response to ozone, it is not possible to identify threshold values above which 

ozone is consistently toxic for all plants. The next few paragraphs present additional 

information on ozone damage to trees, ecosystems, agronomic crops and urban ornamentals. 

Ozone also has been conclusively shown to cause discernible injury to forest 

trees.149,150 In terms of forest productivity and ecosystem diversity, ozone may be the 

pollutant with the greatest potential for regional-scale forest impacts. Studies have 

demonstrated repeatedly that ozone concentrations commonly observed in polluted areas can 

have substantial impacts on plant function.151,152 

Because plants are at the base of the food web in many ecosystems, changes to the 

plant community can affect associated organisms and ecosystems (including the suitability of 
Environmental and Health Impacts 

7-17 

habitats that support threatened or endangered species and below ground organisms living in 

the root zone). Ozone impacts at the community and ecosystem level vary widely depending 

upon numerous factors, including concentration and temporal variation of tropospheric ozone, 

species composition, soil properties and climatic factors.153 In most instances, responses to 

chronic or recurrent exposure in forested ecosystems are subtle and not observable for many 

years. These injuries can cause stand-level forest decline in sensitive ecosystems.154,155,156 It 

is not yet possible to predict ecosystem responses to ozone with much certainty; however, 

considerable knowledge of potential ecosystem responses has been acquired through longterm observations in highly damaged forests in the United States. 

Laboratory and field experiments have also shown reductions in yields for agronomic 

crops exposed to ozone, including vegetables (e.g., lettuce) and field crops (e.g., cotton and 

wheat). The most extensive field experiments, conducted under the National Crop Loss 

Assessment Network (NCLAN) examined 15 species and numerous cultivars. The NCLAN 

results show that “several economically important crop species are sensitive to ozone levels 

typical of those found in the United States.”157 In addition, economic studies have shown 

reduced economic benefits as a result of predicted reductions in crop yields associated with 

observed ozone levels.158,159,160 

Urban ornamentals represent an additional vegetation category likely to experience 

some degree of negative effects associated with exposure to ambient ozone levels. It is 

estimated that more than $20 billion (1990 dollars) are spent annually on landscaping using 

ornamentals, both by private property owners/tenants and by governmental units responsible 

for public areas.161 This is therefore a potentially costly environmental effect. However, in 

the absence of adequate exposure-response functions and economic damage functions for the 

potential range of effects relevant to these types of vegetation, no direct quantitative analysis 

has been conducted. 

Air pollution can have noteworthy cumulative impacts on forested ecosystems by 

affecting regeneration, productivity, and species composition.162 In the U.S., ozone in the 

lower atmosphere is one of the pollutants of primary concern. Ozone injury to forest plants 

can be diagnosed by examination of plant leaves. Foliar injury is usually the first visible sign 

of injury to plants from ozone exposure and indicates impaired physiological processes in the 

leaves.163 

In the U.S. this indicator is based on data from the U.S. Department of Agriculture 

(USDA) Forest Service Forest Inventory and Analysis (FIA) program. As part of its Phase 3 

program, formerly known as Forest Health Monitoring, FIA examines ozone injury to ozonesensitive plant species at ground monitoring sites in forest land across the country. For this 

indicator, forest land does not include woodlots and urban trees. Sites are selected using a 

systematic sampling grid, based on a global sampling design.164,165 At each site that has at 

least 30 individual plants of at least three ozone-sensitive species and enough open space to 

ensure that sensitive plants are not protected from ozone exposure by the forest canopy, FIA 

looks for damage on the foliage of ozone-sensitive forest plant species. Monitoring of ozone 

injury to plants by the USDA Forest Service has expanded over the last 10 years from 

monitoring sites in 10 states in 1994 to nearly 1,000 monitoring sites in 41 states in 2002. 
Draft Regulatory Impact Analysis 

7-18 

7.1.2.2.1 Recent Ozone Data for the U.S. 

 There is considerable regional variation in ozone-related visible foliar injury to 

sensitive plants in the U.S. The U.S. EPA has developed an environmental indicator based on 

data from the U.S. Department of Agriculture (USDA) Forest Service Forest Inventory and 

Analysis (FIA) program which examines ozone injury to ozone-sensitive plant species at 

ground monitoring sites in forest land across the country (This indicator does not include 

woodlots and urban trees). Sites are selected using a systematic sampling grid, based on a 

global sampling design.166, 167 Because ozone injury is cumulative over the course of the 

growing season, examinations are conducted in July and August, when ozone injury is 

typically highest. The data underlying the indictor in Figure 7-2 are based on averages of all 

observations collected in 2002, the latest year for which data are publicly available at the time 

the study was conducted, and are broken down by U.S. EPA Region. Ozone damage to forest 

plants is classified using a subjective five-category biosite index based on expert opinion, but 

designed to be equivalent from site to site. Ranges of biosite values translate to no injury, low 

or moderate foliar injury (visible foliar injury to highly sensitive or moderately sensitive 

plants, respectively), and high or severe foliar injury, which would be expected to result in 

tree-level or ecosystem-level responses, respectively.168, 169

 The highest percentages of observed high and severe foliar injury, those which are 

most likely to be associated with tree or ecosystem-level responses, are primarily found in the 

Mid-Atlantic and Southeast regions. In EPA Region 3 (which comprises the States of 

Pennsylvania, West Virginia, Virginia, Delaware, Maryland and Washington D.C.), 12% of 

ozone-sensitive plants showed signs of high or severe foliar damage, and in Regions 2 (States 

of New York, New Jersey), and 4 (States of North Carolina, South Carolina, Kentucky, 

Tennessee, Georgia, Florida, Alabama, and Mississippi) the values were 10% and 7%, 

respectively. The sum of high and severe ozone injury ranged from 2% to 4% in EPA Region 

1 (the six New England States), Region 7 (States of Missouri, Iowa, Nebraska and Kansas), 

and Region 9 (States of California, Nevada, Hawaii and Arizona). The percentage of sites 

showing some ozone damage was about 45% in each of these EPA Regions. 
Environmental and Health Impacts 

7-19 

Figure 7-2 Ozone Injury to Forest Plants in U.S. by EPA Regions, 2002ab 

7.1.2.2.1.1 Indicator Limitations 

 Field and laboratory studies were reviewed to identify the forest plant species in each 

region that are highly sensitive to ozone air pollution. Other forest plant species, or even 
Draft Regulatory Impact Analysis 

7-20 

genetic variants of the same species, may not be harmed at ozone levels that cause effects on 

the selected ozone-sensitive species. 

 Because species distributions vary regionally, different ozone-sensitive plant species 

were examined in different parts of the country. These target species could vary with 

respect to ozone sensitivity, which might account for some of the apparent differences in 

ozone injury among regions of the U.S. 

 Ozone damage to foliage is considerably reduced under conditions of low soil 

moisture, but most of the variability in the index (70%) was explained by ozone 

concentration.170 Ozone may have other adverse impacts on plants (e.g., reduced 

productivity) that do not show signs of visible foliar injury.171

 Though FIA has extensive spatial coverage based on a robust sample design, not all 

forested areas in the U.S. are monitored for ozone injury. Even though the biosite data have 

been collected over multiple years, most biosites were not monitored over the entire period, 

so these data cannot provide more than a baseline for future trends. 

7.1.2.3 Ozone Impacts on Forest Health 

 Air pollution can impact the environment and affect ecological systems, leading to 

changes in the biological community (both in the diversity of species and the health and vigor 

of individual species). As an example, many studies have shown that ground-level ozone 

reduces the health of plants including many commercial and ecologically important forest tree 

species throughout the United States.172 

When ozone is present in the air, it can enter the leaves of plants, where it can cause 

significant cellular damage. Since photosynthesis occurs in cells within leaves, the ability of 

the plant to produce energy by photosynthesis can be compromised if enough damage occurs 

to these cells. If enough tissue becomes damaged it can reduce carbon fixation and increase 

plant respiration, leading to reduced growth and/or reproduction in young and mature trees. 

Ozone stress also increases the susceptibility of plants to disease, insects, fungus, and other 

environmental stressors (e.g., harsh weather). Because ozone damage can consist of visible 

injury to leaves, it also reduces the aesthetic value of ornamental vegetation and trees in urban 

landscapes, and negatively affects scenic vistas in protected natural areas. 

Assessing the impact of ground-level ozone on forests in the eastern United States 

involves understanding the risks to sensitive tree species from ambient ozone concentrations 

and accounting for the prevalence of those species within the forest. As a way to quantify the 

risks to particular plants from ground-level ozone, scientists have developed ozoneexposure/tree-response functions by exposing tree seedlings to different ozone levels and 

measuring reductions in growth as “biomass loss.” Typically, seedlings are used because they 

are easy to manipulate and measure their growth loss from ozone pollution. The mechanisms 

of susceptibility to ozone within the leaves of seedlings and mature trees are identical, though 

the magnitude of the effect may be higher or lower depending on the tree species. 173 
Environmental and Health Impacts 

7-21 

Some of the common tree species in the United States that are sensitive to ozone are black 

cherry (Prunus serotina), tulip-poplar (Liriodendron tulipifera), eastern white pine (Pinus 

strobus). Ozone-exposure/tree-response functions have been developed for each of these tree 

species, as well as for aspen (Populus tremuliodes), and ponderosa pine (Pinus ponderosa). 

Other common tree species, such as oak (Quercus spp.) and hickory (Carya spp.), are not 

nearly as sensitive to ozone. Consequently, with knowledge of the distribution of sensitive 

species and the level of ozone at particular locations, it is possible to estimate a “biomass 

loss” for each species across their range. 

7.1.2.4 Particulate Matter Deposition 

 Particulate matter contributes to adverse effects on vegetation and ecosystems, and to 

soiling and materials damage. These welfare effects result predominately from exposure to 

excess amounts of specific chemical species, regardless of their source or predominant form 

(particle, gas or liquid). Reflecting this fact, the PM AQCD concludes that regardless of size 

fractions, particles containing nitrates and sulfates have the greatest potential for widespread 

environmental significance, while effects are also related to other chemical constituents found 

in ambient PM, such as trace metals and organics. The following characterizations of the 

nature of these welfare effects are based on the information contained in the PM AQCD and 

PM Staff Paper.174,175

7.1.2.4.1 Deposition of Nitrogen and Sulfur 

 Nitrogen and sulfur interactions in the environment are highly complex. Both are 

essential, and sometimes limiting, nutrients needed for growth and productivity. Excesses of 

nitrogen or sulfur can lead to soil and water acidification, nutrient enrichment, and 

eutrophication.176 

The process of acidification affects both freshwater aquatic and terrestrial ecosystems. 

Acid deposition causes acidification of sensitive surface waters. The effects of acid deposition 

on aquatic systems depend largely upon the ability of the ecosystem to neutralize the 

additional acid. As acidity increases, aluminum leached from soils and sediments, flows into 

lakes and streams and can be toxic to both terrestrial and aquatic biota. The lower pH 

concentrations and higher aluminum levels resulting from acidification make it difficult for 

some fish and other aquatic organisms to survive, grow, and reproduce. Research on effects 

of acid deposition on forest ecosystems has come to focus increasingly on the biogeochemical 

processes that affect uptake, retention, and cycling of nutrients within these ecosystems. 

Decreases in available base cations from soils are at least partly attributable to acid 

deposition. Base cation depletion is a cause for concern because of the role these ions play in 

acid neutralization and, because calcium, magnesium and potassium are essential nutrients for 

plant growth and physiology. Changes in the relative proportions of these nutrients, 

especially in comparison with aluminum concentrations, have been associated with declining 

forest health. 

At current ambient levels, risks to vegetation from short-term exposures to dry 

deposited particulate nitrate or sulfate are low. However, when found in acid or acidifying 

deposition, such particles do have the potential to cause direct leaf injury. Specifically, the 
Draft Regulatory Impact Analysis 

7-22 

responses of forest trees to acid precipitation (rain, snow) include accelerated weathering of 

leaf cuticular surfaces, increased permeability of leaf surfaces to toxic materials, water, and 

disease agents; increased leaching of nutrients from foliage; and altered reproductive 

processes—all which serve to weaken trees so that they are more susceptible to other stresses 

(e.g., extreme weather, pests, pathogens). Acid deposition with levels of acidity associated 

with the leaf effects described above are currently found in some locations in the eastern 

U.S.177 Even higher concentrations of acidity can be present in occult depositions (e.g., fog, 

mist or clouds) which more frequently impacts higher elevations. Thus, the risk of leaf injury 

occurring from acid deposition in some areas of the eastern U.S. is high. Nitrogen deposition 

has also been shown to impact ecosystems in the western U.S. A study conducted in the 

Columbia River Gorge National Scenic Area (CRGNSA), located along a portion of the 

Oregon/Washington border, indicates that lichen communities in the CRGNSA have shifted 

to a higher proportion of nitrophilous species and the nitrogen content of lichen tissue is 

elevated.178 Lichens are sensitive indicators of nitrogen deposition effects to terrestrial 

ecosystems and the lichen studies in the Columbia River Gorge clearly show that ecological 

effects from air pollution are occurring. 

Some of the most significant detrimental effects associated with excess nitrogen 

deposition are those associated with a syndrome known as nitrogen saturation. These effects 

include: (1) decreased productivity, increased mortality, and/or shifts in plant community 

composition, often leading to decreased biodiversity in many natural habitats wherever 

atmospheric reactive nitrogen deposition increases significantly above background and critical 

thresholds are exceeded; (2) leaching of excess nitrate and associated base cations from soils 

into streams, lakes, and rivers, and mobilization of soil aluminum; and (3) fluctuation of 

ecosystem processes such as nutrient and energy cycles through changes in the functioning 

and species composition of beneficial soil organisms.179

In the U.S. numerous forests now show severe symptoms of nitrogen saturation. 

These forests include: the northern hardwoods and mixed conifer forests in the Adirondack 

and Catskill Mountains of New York; the red spruce forests at Whitetop Mountain, Virginia, 

and Great Smoky Mountains National Park, North Carolina; mixed hardwood watersheds at 

Fernow Experimental Forest in West Virginia; American beech forests in Great Smoky 

Mountains National Park, Tennessee; mixed conifer forests and chaparral watersheds in 

southern California and the southwestern Sierra Nevada in Central California; the alpine 

tundra/subalpine conifer forests of the Colorado Front Range; and red alder forests in the 

Cascade Mountains in Washington. 

Excess nutrient inputs into aquatic ecosystems (i.e. streams, rivers, lakes, estuaries or 

oceans) either from direct atmospheric deposition, surface runoff, or leaching from nitrogen 

saturated soils into ground or surface waters can contribute to conditions of severe water 

oxygen depletion; eutrophication and algae blooms; altered fish distributions, catches, and 

physiological states; loss of biodiversity; habitat degradation; and increases in the incidence 

of disease. 

Atmospheric deposition of nitrogen is a significant source of total nitrogen to many 

estuaries in the United States. The amount of nitrogen entering estuaries that is ultimately 

attributable to atmospheric deposition is not well-defined. On an annual basis, atmospheric 
Environmental and Health Impacts 

7-23 

nitrogen deposition may contribute significantly to the total nitrogen load, depending on the 

size and location of the watershed. In addition, episodic nitrogen inputs, which may be 

ecologically important, may play a more important role than indicated by the annual average 

concentrations. Estuaries in the U.S. that suffer from nitrogen enrichment often experience a 

condition known as eutrophication. Symptoms of eutrophication include changes in the 

dominant species of phytoplankton, low levels of oxygen in the water column, fish and 

shellfish kills, outbreaks of toxic alga, and other population changes which can cascade 

throughout the food web. In addition, increased phytoplankton growth in the water column 

and on surfaces can attenuate light causing declines in submerged aquatic vegetation, which 

serves as an important habitat for many estuarine fish and shellfish species. 

Severe and persistent eutrophication often directly impacts human activities. For 

example, losses in the nation’s fishery resources may be directly caused by fish kills 

associated with low dissolved oxygen and toxic blooms. Declines in tourism occur when low 

dissolved oxygen causes noxious smells and floating mats of algal blooms create unfavorable 

aesthetic conditions. Risks to human health increase when the toxins from algal blooms 

accumulate in edible fish and shellfish, and when toxins become airborne, causing respiratory 

problems due to inhalation. According to a NOAA report, more than half of the nation’s 

estuaries have moderate to high expressions of at least one of these symptoms – an indication 

that eutrophication is well developed in more than half of U.S. estuaries.180

7.1.2.4.2 Deposition of Heavy Metals 

 Heavy metals, including cadmium, copper, lead, chromium, mercury, nickel and 

zinc, have the greatest potential for influencing forest growth (PM AQCD, p. 4-87).181 

Investigation of trace metals near roadways and industrial facilities indicate that a substantial 

load of heavy metals can accumulate on vegetative surfaces. Copper, zinc, and nickel have 

been documented to cause direct toxicity to vegetation under field conditions (PM AQCD, p. 

4-75). Little research has been conducted on the effects associated with mixtures of 

contaminants found in ambient PM. While metals typically exhibit low solubility, limiting 

their bioavailability and direct toxicity, chemical transformations of metal compounds occur 

in the environment, particularly in the presence of acidic or other oxidizing species. These 

chemical changes influence the mobility and toxicity of metals in the environment. Once 

taken up into plant tissue, a metal compound can undergo chemical changes, accumulate and 

be passed along to herbivores or can re-enter the soil and further cycle in the environment. 

Although there has been no direct evidence of a physiological association between tree injury 

and heavy metal exposures, heavy metals have been implicated because of similarities 

between metal deposition patterns and forest decline (PM AQCD, p. 4-76). This 

hypothesized relationship/correlation was further explored in high elevation forests in the 

northeastern U.S. These studies measured levels of a group of intracellular compounds found 

in plants that bind with metals and are produced by plants as a response to sublethal 

concentrations of heavy metals. These studies indicated a systematic and significant increase 

in concentrations of these compounds associated with the extent of tree injury. These data 

strongly imply that metal stress causes tree injury and contributes to forest decline in the 

northeastern United States (PM AQCD 4-76,77).182 Contamination of plant leaves by heavy 

metals can lead to elevated soil levels. Trace metals absorbed into the plant frequently bind to 

the leaf tissue, and then are lost when the leaf drops (PM AQCD, p. 4-75). As the fallen 
Draft Regulatory Impact Analysis 

7-24 

leaves decompose, the heavy metals are transferred into the soil.183,184 

The environmental sources and cycling of mercury are currently of particular concern 

due to the bioaccumulation and biomagnification of this metal in aquatic ecosystems and the 

potent toxic nature of mercury in the forms in which is it ingested by people and other 

animals. Mercury is unusual compared with other metals in that it largely partitions into the 

gas phase (in elemental form), and therefore has a longer residence time in the atmosphere 

than a metal found predominantly in the particle phase. This property enables mercury to 

travel far from the primary source before being deposited and accumulating in the aquatic 

ecosystem. The major source of mercury in the Great Lakes is from atmospheric deposition, 

accounting for approximately eighty percent of the mercury in Lake Michigan.185,186 Over 

fifty percent of the mercury in the Chesapeake Bay has been attributed to atmospheric 

deposition.187 Overall, the National Science and Technology Council identifies atmospheric 

deposition as the primary source of mercury to aquatic systems.188 Forty-four states have 

issued health advisories for the consumption of fish contaminated by mercury; however, most 

of these advisories are issued in areas without a mercury point source. 

Elevated levels of zinc and lead have been identified in streambed sediments, and 

these elevated levels have been correlated with population density and motor vehicle 

use.189,190 Zinc and nickel have also been identified in urban water and soils. In addition, 

platinum, palladium, and rhodium, metals found in the catalysts of modern motor vehicles, 

have been measured at elevated levels along roadsides.191 Plant uptake of platinum has been 

observed at these locations. 

7.1.2.4.3 Deposition of Polycyclic Organic Matter 

 Polycyclic organic matter (POM) is a byproduct of incomplete combustion and 

consists of organic compounds with more than one benzene ring and a boiling point greater 

than or equal to 100 degrees centigrade.192 Polycyclic aromatic hydrocarbons (PAHs) are a 

class of POM that contains compounds which are known or suspected carcinogens. 

Major sources of PAHs include mobile sources. PAHs in the environment may be 

present as a gas or adsorbed onto airborne particulate matter. Since the majority of PAHs are 

adsorbed onto particles less than 1.0 μm in diameter, long range transport is possible. 

However, studies have shown that PAH compounds adsorbed onto diesel exhaust particulate 

and exposed to ozone have half lives of 0.5 to 1.0 hours.193 

Since PAHs are insoluble, the compounds generally are particle reactive and 

accumulate in sediments. Atmospheric deposition of particles is believed to be the major 

source of PAHs to the sediments of Lake Michigan.194,195 Analyses of PAH deposition in 

Chesapeake and Galveston Bay indicate that dry deposition and gas exchange from the 

atmosphere to the surface water predominate.196,197 Sediment concentrations of PAHs are 

high enough in some segments of Tampa Bay to pose an environmental health threat. EPA 

funded a study to better characterize the sources and loading rates for PAHs into Tampa 

Bay.198 PAHs that enter a water body through gas exchange likely partition into organic rich 

particles and can be biologically recycled, while dry deposition of aerosols containing PAHs 

tend to be more resistant to biological recycling.199 Thus, dry deposition is likely the main 
Environmental and Health Impacts 

7-25 

pathway for PAH concentrations in sediments while gas/water exchange at the surface may 

lead to PAH distribution into the food web, leading to increased health risk concerns. 

Trends in PAH deposition levels are difficult to discern because of highly variable 

ambient air concentrations, lack of consistency in monitoring methods, and the significant 

influence of local sources on deposition levels.200 Van Metre et al. noted PAH concentrations 

in urban reservoir sediments have increased by 200-300% over the last forty years and 

correlate with increases in automobile use.201 

Cousins et al. estimate that more than ninety percent of semi-volatile organic 

compound (SVOC) emissions in the United Kingdom deposit on soil.202 An analysis of PAH 

concentrations near a Czechoslovakian roadway indicated that concentrations were thirty 

times greater than background.203

7.1.2.4.4 Materials Damage and Soiling 

 The effects of the deposition of atmospheric pollution, including ambient PM, on 

materials are related to both physical damage and impaired aesthetic qualities. The deposition 

of PM (especially sulfates and nitrates) can physically affect materials, adding to the effects of 

natural weathering processes, by potentially promoting or accelerating the corrosion of 

metals, by degrading paints, and by deteriorating building materials such as concrete and 

limestone. Only chemically active fine particles or hygroscopic coarse particles contribute to 

these physical effects. In addition, the deposition of ambient PM can reduce the aesthetic 

appeal of buildings and culturally important articles through soiling. Particles consisting 

primarily of carbonaceous compounds cause soiling of commonly used building materials and 

culturally important items such as statues and works of art. 

7.1.2.5 Environmental Effects of Air Toxics 

 Fuel combustion emissions contribute to ambient levels of pollutants that contribute 

to adverse effects on vegetation. Volatile organic compounds (VOCs), some of which are 

considered air toxics, have long been suspected to play a role in vegetation damage.204 In 

laboratory experiments, a wide range of tolerance to VOCs has been observed.205 Decreases 

in harvested seed pod weight have been reported for the more sensitive plants, and some 

studies have reported effects on seed germination, flowering and fruit ripening. Effects of 

individual VOCs or their role in conjunction with other stressors (e.g., acidification, drought, 

temperature extremes) have not been well studied. In a recent study of a mixture of VOCs 

including ethanol and toluene on herbaceous plants, significant effects on seed production, 

leaf water content and photosynthetic efficiency were reported for some plant species.206

Research suggests an adverse impact of vehicle exhaust on plants, which has in some 

cases been attributed to aromatic compounds and in other cases to nitrogen oxides.207,208,209 

The impacts of VOCs on plant reproduction may have long-term implications for biodiversity 

and survival of native species near major roadways. Most of the studies of the impacts of 

VOCs on vegetation have focused on short-term exposure and few studies have focused on 

long-term effects of VOCs on vegetation and the potential for metabolites of these compounds 

to affect herbivores or insects. 
Draft Regulatory Impact Analysis 

7-26 

7.2 Non-GHG Air Quality Impacts 

7.2.1 Introduction 

 Chapter 5 of this DRIA presents the projected emissions changes due to the proposed 

rule. Once the emissions changes are projected the next step is to look at how the ambient air 

quality would be impacted by those emissions changes. Although the purpose of this proposal 

is to address greenhouse gas emissions, this proposed rule would also impact emissions of 

criteria and hazardous air pollutants. Section 7.2.2 describes current ambient levels of PM, 

ozone, CO and some air toxics without the standards being proposed in this rule. No air 

quality modeling was done for this DRIA to project the impacts of the proposed rule. Air 

quality modeling will be done for the final rule, however, and those plans are discussed in 

Section 7.2.3. 

7.2.2 Current Levels of Pollutants 

7.2.2.1 Particulate Matter 

 As described in Section 7.1.1.1, PM causes adverse health effects, and the U.S. 

government has set national standards to provide requisite protection against those health 

effects. There are two U.S. national ambient air quality standards (NAAQS) for PM2.5: an 

annual standard (15 μg/m3

) and a 24-hour standard (35 μg/m3). The most recent revisions to 

these standards were in 1997 and 2006. In 2005 the U.S. EPA designated nonattainment areas 

for the 1997 PM2.5 NAAQS (70 FR 19844, April 14, 2005).K As of June 5, 2009 there are 39 

1997 PM2.5 nonattainment areas comprised of 208 full or partial counties with a total 

population exceeding 88 million. Area designations for the 2006 24-hour PM2.5 NAAQS are 

expected to be promulgated in 2009 and become effective 90 days after publication in the 

Federal Register. 

States with PM2.5 nonattainment areas will be required to take action to bring those 

areas into compliance in the future. Most 1997 PM2.5 nonattainment areas are required to 

attain the 1997 PM2.5 NAAQS in the 2010 to 2015 time frame and then be required to 

maintain the 1997 PM2.5 NAAQS thereafter.210 The 2006 24-hour PM2.5 nonattainment areas 

will be required to attain the 2006 24-hour PM2.5 NAAQS in the 2014 to 2019 time frame and 

then be required to maintain the 2006 24-hour PM2.5 NAAQS thereafter.211 

7.2.2.2 Ozone 

 As described in Section 7.1.1.2, ozone causes adverse health effects, and the U.S. 

government has set national standards to protect against those health effects. The NAAQS for 

ozone is an 8-hour standard set at 0.075 ppm. The most recent revision to this standard was in 

 K A nonattainment area is defined in the Clean Air Act (CAA) as an area that is violating an ambient standard or 

is contributing to a nearby area that is violating the standard. 
Environmental and Health Impacts 

7-27 

2008; the previous 8-hour ozone standard, set in 1997, had been 0.08 ppm. In 2004 the U.S. 

EPA designated nonattainment areas for the 1997 8-hour ozone NAAQS (69 FR 23858, April 

30, 2004).L

 As of June 5, 2009 there are 55 1997 8-hour ozone nonattainment areas 

comprised of 290 full or partial counties with a total population of approximately 132 

million.212 Nonattainment designations for the 2008 8-hour ozone standard are currently 

under development. 

States with ozone nonattainment areas are required to take action to bring those areas 

into compliance in the future. The attainment date assigned to an ozone nonattainment area is 

based on the area’s classification. Most ozone nonattainment areas are required to attain the 

1997 8-hour ozone NAAQS in the 2007 to 2013 time frame and then to maintain it 

thereafter.M The attainment dates associated with the potential nonattainment areas based on 

the 2008 8-hour ozone NAAQS will likely be in the 2013 to 2021 timeframe, depending on 

the severity of the problem in each area. Table 7-2 provides an estimate, based on 2004-06 air 

quality data, of the counties with design values greater than the 2008 ozone NAAQS. 

Table 7-2 Counties with Design Values Greater Than the 2008 Ozone NAAQS Based on 2005-2007 Air 

Quality Data 

 NUMBER OF 

COUNTIES 

POPULATIONA

1997 Ozone Standard: counties within the 57 

areas currently designated as nonattainment 

293 131,977,890 

2008 Ozone Standard: additional counties that 

would not meet the 2008 NAAQSb

227 41,285,262 

Total 520 173,263,152 

Notes: 

a

 Population numbers are from 2000 census data. 

b

 Attainment designations for the 2008 ozone NAAQS have not yet been made. Nonattainment for the 2008 

Ozone NAAQS will be based on three years of air quality data from later years. Also, the county numbers in the 

table include only the counties with monitors violating the 2008 Ozone NAAQS. The numbers in this table may 

be an underestimate of the number of counties and populations that will eventually be included in areas with 

multiple counties designated nonattainment. 

7.2.2.3 Carbon Monoxide 

 As described in Section 7.1.1.4, CO causes adverse health effects, and the U.S. 

government has set national standards to protect against those health effects. There are two 

CO NAAQS. The 8-hour average CO NAAQS is 9 ppm, not to be exceeded more than once 

per year, and the 1-hour average CO NAAQS is 35 ppm, not to be exceeded more than once 

 L

 A nonattainment area is defined in the Clean Air Act (CAA) as an area that is violating an ambient standard or 

is contributing to a nearby area that is violating the standard. 

M The Los Angeles South Coast Air Basin 8-hour ozone nonattainment area is designated as severe and will have 

to attain before June 15, 2021. The South Coast Air Basin has requested to be reclassified as an extreme 

nonattainment area which will make its attainment date June 15, 2024. The San Joaquin Valley Air Basin 8-hour 

ozone nonattainment area is designated as serious and will have to attain before June 15, 2013. The San Joaquin 

Valley Air Basin has requested to be reclassified as an extreme nonattainment area which will make its 

attainment date June 15, 2024. 
Draft Regulatory Impact Analysis 

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per year. The two standards are the identical standards that were promulgated in 1971. 

Reviews of the CO NAAQS in both 1985 and 1994 kept the standards at the same levels. As 

of June 5, 2009 there are approximately 479,000 people living in a portion of Clark Co., NV 

which is currently the only area in the country that is designated as nonattainment for CO, see 

Table 7-3.213 The CO NAAQS is currently under review and a final rule is expected to be 

final in May 2011. 

Table 7-3 Classified Carbon Monoxide Nonattainment Areas as of June 2009 

AREA 

CLASSIFICATION POPULATION 

Clark County (p), NV Nonattainment 478,766 

Total 478,766 

7.2.2.4 Air Toxics 

 According to the National Air Toxics Assessment (NATA) for 2002, mobile sources 

were responsible for 47 percent of outdoor toxic emissions and over 50 percent of the cancer 

risk.214 Nearly the entire U.S. population was exposed to an average concentration of air 

toxics that has the potential for adverse noncancer respiratory health effects. EPA recently 

finalized vehicle and fuel controls to reduce mobile source air toxics.215 In addition, over the 

years, EPA has implemented a number of mobile source and fuel controls resulting in VOC 

reductions, which also reduce air toxic emissions. Modeling from the recent Mobile Source 

Air Toxics (MSAT) rule suggests that the mobile source contribution to ambient benzene 

concentrations is projected to decrease over 40% by 2015, with a decrease in ambient benzene 

concentration from all sources of about 25%. Although benzene is used as an example, the 

downward trend is projected for other air toxics as well. See the RIA for the final MSAT rule 

for more information on ambient air toxics projections.216

7.2.3 Impacts on Future Air Quality 

 Air quality models use mathematical and numerical techniques to simulate the 

physical and chemical processes that affect air pollutants as they disperse and react in the 

atmosphere. Based on inputs of meteorological data and source information, these models are 

designed to characterize primary pollutants that are emitted directly into the atmosphere and 

secondary pollutants that are formed as a result of complex chemical reactions within the 

atmosphere. Photochemical air quality models have become widely recognized and routinely 

utilized tools for regulatory analysis by assessing the effectiveness of control strategies. 

These models are applied at multiple spatial scales from local, regional, national, and global. 

Section 7.2.3.1 provides more detail on the photochemical model, the Community Multi-scale 

Air Quality (CMAQ) model, which will be utilized for the final rule analysis. 
Environmental and Health Impacts 

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7.2.3.1 Community Multi-scale Air Quality (CMAQ) Modeling Plans 

 Full-scale photochemical air quality modeling is necessary to accurately project levels 

of PM2.5, ozone, CO and air toxics. For the final rule, a national-scale air quality modeling 

analysis will be performed to analyze the impacts of the vehicle standards on PM2.5, ozone, 

and selected air toxics (i.e., benzene, formaldehyde, acetaldehyde, acrolein and 1,3-

butadiene). The length of time needed to prepare the necessary emissions inventories, in 

addition to the processing time associated with the modeling itself, has precluded us from 

performing air quality modeling for this proposal. 

Section II.G.1 of the preamble presents projections of the changes in criteria pollutant 

and air toxics emissions due to the proposed vehicle standards; the basis for those estimates is 

set out in Chapter 5 of the DRIA. The atmospheric chemistry related to ambient 

concentrations of PM2.5, ozone and air toxics is very complex, and making predictions based 

solely on emissions changes is extremely difficult. However, based on the magnitude of the 

emissions changes predicted to result from the proposed vehicle standards, we expect that 

there will be an improvement in ambient air quality, pending a more comprehensive analysis 

for the final rule. 

For the final rule, EPA intends to use a 2005-based Community Multi-scale Air 

Quality (CMAQ) modeling platform as the tool for the air quality modeling. The CMAQ 

modeling system is a comprehensive three-dimensional grid-based Eulerian air quality model 

designed to estimate the formation and fate of oxidant precursors, primary and secondary PM 

concentrations and deposition, and air toxics, over regional and urban spatial scales (e.g., over 

the contiguous U.S.).217,218,219 The CMAQ model is a well-known and well-established tool 

and is commonly used by EPA for regulatory analyses, for instance the recent ozone NAAQS 

proposal, and by States in developing attainment demonstrations for their State 

Implementation Plans.220 The CMAQ model (version 4.6) was peer-reviewed in February of 

2007 for EPA as reported in “Third Peer Review of CMAQ Model,” and the EPA Office of 

Research and Development (ORD) peer review report which includes version 4.7 is currently 

being finalized.221

CMAQ includes many science modules that simulate the emission, production, decay, 

deposition and transport of organic and inorganic gas-phase and particle-phase pollutants in 

the atmosphere. We intend to use the most recent CMAQ version (version 4.7), which was 

officially released by EPA’s Office of Research and Development (ORD) in December 2008 

and reflects updates to earlier versions in a number of areas to improve the underlying 

science. These include (1) enhanced secondary organic aerosol (SOA) mechanism to include 

chemistry of isoprene, sesquiterpene, and aged in-cloud biogenic SOA in addition to terpene; 

(2) improved vertical convective mixing; (3) improved heterogeneous reaction involving 

nitrate formation; and (4) an updated gas-phase chemistry mechanism, Carbon Bond 05 

(CB05), with extensions to model explicit concentrations of air toxic species as well as 

chlorine and mercury. This mechanism, CB05-toxics, also computes concentrations of 

species that are involved in aqueous chemistry and that are precursors to aerosols. 

The CMAQ modeling domain will encompass all of the lower 48 States and portions 

of Canada and Mexico. The modeling domain will include a large continental U.S. 36 km 
Draft Regulatory Impact Analysis 

7-30 

grid and two 12 km grids (an Eastern US and a Western US domain), as shown in Figure 7-3. 

The modeling domain will contain 14 vertical layers with the top of the modeling domain at 

about 16,200 meters, or 100 millibars (mb). 

Figure 7-3 CMAQ 12-km Eastern and Western US modeling domains 

The key inputs to the CMAQ model include emissions from anthropogenic and 

biogenic sources, meteorological data, and initial and boundary conditions. The CMAQ 

meteorological input files will be derived from simulations of the Pennsylvania State 

University / National Center for Atmospheric Research Mesoscale Model222 for the entire 

year of 2005. This model, commonly referred to as MM5, is a limited-area, nonhydrostatic, 

terrain-following system that solves for the full set of physical and thermodynamic equations 

which govern atmospheric motions.223 The meteorology for the national 36 km grid and the 

12 km Eastern and Western U.S. grids will be developed by EPA and described in more detail 

within the final RIA and the technical support document for the final rule air quality 

modeling. 

The lateral boundary and initial species concentrations will be provided by a threedimensional global atmospheric chemistry model, the GEOS-CHEM model.224 The global 

GEOS-CHEM model simulates atmospheric chemical and physical processes driven by 

assimilated meteorological observations from the NASA’s Goddard Earth Observing System 
Environmental and Health Impacts 

7-31 

(GEOS). This model will be run for 2005 with a grid resolution of 2 degree x 2.5 degree 

(latitude-longitude) and 20 vertical layers. The predictions will be used to provide one-way 

dynamic boundary conditions at three-hour intervals and an initial concentration field for the 

36 km CMAQ simulations. The future base conditions from the 36 km coarse grid modeling 

will be used as the initial/boundary state for all subsequent 12 km finer grid modeling. 

 

7.3 Quantified and Monetized Co-Pollutant Health and Environmental 

Impacts 

 This section presents EPA’s analysis of the co-pollutant health and environmental 

impacts that can be expected to occur as a result of the proposed light-duty vehicle GHG rule. 

GHG emissions are predominantly the byproduct of fossil fuel combustion processes that also 

produce criteria and hazardous air pollutants. The vehicles that are subject to the proposed 

standards are also significant sources of mobile source air pollution such as direct PM, NOx, 

VOCs and air toxics. The proposed standards would affect exhaust emissions of these 

pollutants from vehicles. They would also affect emissions from upstream sources related to 

changes in fuel consumption. Changes in ambient ozone, PM2.5, and air toxics that would 

result from the proposed standards are expected to affect human health in the form of 

premature deaths and other serious human health effects, as well as other important public 

health and welfare effects. 

It is important to quantify the health and environmental impacts associated with the 

proposed standard because a failure to adequately consider these ancillary co-pollutant 

impacts could lead to an incorrect assessment of their net costs and benefits. Moreover, copollutant impacts tend to accrue in the near term, while any effects from reduced climate 

change mostly accrue over a time frame of several decades or longer. 

EPA typically quantifies and monetizes the health and environmental impacts related 

to both PM and ozone in its regulatory impact analyses (RIAs), when possible. However, we 

were unable to do so in time for this proposal. EPA attempts to make emissions and air 

quality modeling decisions early in the analytical process so that we can complete the 

photochemical air quality modeling and use that data to inform the health and environmental 

impacts analysis. Resource and time constraints precluded the Agency from completing this 

work in time for the proposal. Instead, EPA is using PM-related benefits-per-ton values as an 

interim approach to estimating the PM-related benefits of the proposal. We also provide a 

complete characterization of the health and environmental impacts that will be quantified and 

monetized for the final rulemaking. 

This section is split into two sub-sections: the first presents the PM-related benefitsper-ton values used to monetize the PM-related co-benefits associated with the proposal; the 

second explains what PM- and ozone-related health and environmental impacts EPA will 

quantify and monetize in the analysis for the final rule. EPA bases its analyses on peerreviewed studies of air quality and health and welfare effects and peer-reviewed studies of the 

monetary values of public health and welfare improvements, and is generally consistent with 
Draft Regulatory Impact Analysis 

7-32 

benefits analyses performed for the analysis of the final Ozone National Ambient Air Quality 

Standard (NAAQS) and the final PM NAAQS analysis, as well as the recent Portland Cement 

National Emissions Standards for Hazardous Air Pollutants (NESHAP) RIA (U.S. EPA, 

2009a), and NO2 NAAQS (U.S. EPA, 2009b).225,226, 227,228 

Though EPA is characterizing the changes in emissions associated with toxic 

pollutants, we will not be able to quantify or monetize the human health effects associated 

with air toxic pollutants for either the proposal or the final rule analyses. Please refer to 

Chapter 5.5 for more information about the air toxics emissions impacts associated with the 

proposed standards. 

7.3.1 Economic Value of Reductions in Criteria Pollutants 

 As described in Chapter 5.5, the proposed standards would reduce emissions of 

several criteria and toxic pollutants and precursors. In this analysis, EPA estimates the 

economic value of the human health benefits associated with reducing PM2.5 exposure. Due 

to analytical limitations, this analysis does not estimate benefits related to other criteria 

pollutants (such as ozone, NO2 or SO2) or toxic pollutants, nor does it monetize all of the 

potential health and welfare effects associated with PM2.5. 

This analysis uses a “benefit-per-ton” method to estimate a selected suite of PM2.5-

related health benefits described below. These PM2.5 benefit-per-ton estimates provide the 

total monetized human health benefits (the sum of premature mortality and premature 

morbidity) of reducing one ton of directly emitted PM2.5, or its precursors (such as NOx, SOx, 

and VOCs), from a specified source. Ideally, the human health benefits would be estimated 

based on changes in ambient PM2.5 as determined by full-scale air quality modeling. 

However, this modeling was not possible in the timeframe for this proposal. 

The dollar-per-ton estimates used in this analysis are provided in Table 7-4. In the 

summary of costs and benefits, Chapter 8.3 of this RIA, we present the monetized value of 

PM-related improvements associated with the proposal. 

Table 7-4: Benefits-per-ton Values (2007$) Derived Using the ACS Cohort Study for PM-related 

Premature Mortality (Pope et al., 2002)a

 and a 3% Discount Rateb 

All Sourcesd Stationary (Non-EGU) Sources Mobile Sources Yearc

SOx VOC NOx Direct PM2.5 NOx Direct PM2.5 

2015 $28,000 $1,200 $4,700 $220,000 $4,900 $270,000 

2020 $31,000 $1,300 $5,100 $240,000 $5,300 $290,000 

2030 $36,000 $1,500 $6,100 $280,000 $6,400 $350,000 

2040 $43,000 $1,800 $7,200 $330,000 $7,600 $420,000 

a The benefit-per-ton estimates presented in this table are based on an estimate of premature mortality derived 

from the ACS study (Pope et al., 2002). If the benefit-per-ton estimates were based on the Six Cities study 

(Laden et al., 2006), the values would be approximately 145% (nearly two-and-a-half times) larger. 

b The benefit-per-ton estimates presented in this table assume a 3% discount rate in the valuation of premature 

mortality to account for a twenty-year segmented cessation lag. If a 7% discount rate had been used, the values 

would be approximately 9% lower. 
Environmental and Health Impacts 

7-33 

c Benefit-per-ton values were estimated for the years 2015, 2020, and 2030. For 2040, EPA extrapolated 

exponentially based on the growth between 2020 and 2030. 

d Note that the benefit-per-ton value for SOx is based on the value for Stationary (Non-EGU) sources; no SOx 

value was estimated for mobile sources. The benefit-per-ton value for VOCs was estimated across all sources. 

The benefit per-ton technique has been used in previous analyses, including EPA’s 

recent Ozone National Ambient Air Quality Standards (NAAQS) RIA (U.S. EPA, 2008a),229

proposed Portland Cement National Emissions Standards for Hazardous Air Pollutants 

(NESHAP) RIA (U.S. EPA, 2009a),230 and proposed NO2 primary NAAQS (U.S. EPA, 

2009b).231 Table 7-5 shows the quantified and unquantified PM2.5-related co-benefits 

captured in those benefit-per-ton estimates. 

Table 7-5: Human Health and Welfare Effects of PM2.5

Pollutant / 

Effect 

Quantified and Monetized 

in Primary Estimates 

Unquantified Effects 

Changes in: 

PM2.5 Adult premature mortality 

Bronchitis: chronic and acute 

Hospital admissions: respiratory and 

cardiovascular 

Emergency room visits for asthma 

Nonfatal heart attacks (myocardial 

infarction) 

Lower and upper respiratory illness 

Minor restricted-activity days 

Work loss days 

Asthma exacerbations (asthmatic 

population) 

Infant mortality 

Subchronic bronchitis cases 

Low birth weight 

Pulmonary function 

Chronic respiratory diseases other than chronic 

bronchitis 

Non-asthma respiratory emergency room visits 

Visibility 

Household soiling 

Consistent with the proposed NO2 NAAQS,N the benefits estimates utilize the 

concentration-response functions as reported in the epidemiology literature. Readers 

interested in reviewing the complete methodology for creating the benefit-per-ton estimates 

used in this analysis can consult the Technical Support Document (TSD)232 accompanying the 

recent final ozone NAAQS RIA (U.S. EPA, 2008a). Readers can also refer to Fann et al. 

(2009)233 for a detailed description of the benefit-per-ton methodology.O A more detailed 

description of the benefit-per-ton estimates is also provided in the TSD that accompanies this 

rulemaking. 

As described in the documentation for the benefit per-ton estimates cited above, 

national per-ton estimates were developed for selected pollutant/source category 

 NAlthough we summarize the main issues in this chapter, we encourage interested readers to see benefits chapter 

of the proposed primary NO2 NAAQS RIA for a more detailed description of recent changes to the PM benefits 

presentation and preference for the no-threshold model. 

O The values included in this report are different from those presented in the article cited above. Benefits 

methods change to reflect new information and evaluation of the science. Since publication of the June 2009 

article, EPA has made two significant changes to its benefits methods: (1) We no longer assume that a threshold 

exists in PM-related models of health impacts; and (2) We have revised the Value of a Statistical Life to equal 

$6.3 million (year 2000$), up from an estimate of $5.5 million (year 2000$) used in the June 2009 report. Please 

refer to the following website for updates to the dollar-per-ton estimates: 

http://www.epa.gov/air/benmap/bpt.html 
Draft Regulatory Impact Analysis 

7-34 

combinations. The per-ton values calculated therefore apply only to tons reduced from those 

specific pollutant/source combinations (e.g., NO2 emitted from mobile sources; direct PM 

emitted from stationary sources). Our estimate of PM2.5 benefits is therefore based on the 

total direct PM2.5 and PM-related precursor emissions controlled by sector and multiplied by 

each per-ton value. 

The benefit-per-ton coefficients in this analysis were derived using modified versions 

of the health impact functions used in the PM NAAQS Regulatory Impact Analysis. 

Specifically, this analysis uses the benefit-per-ton estimates first applied in the Portland 

Cement NESHAP RIA (U.S. EPA, 2009a), which incorporated functions directly from the 

epidemiology studies without an adjustment for an assumed threshold. Removing the 

threshold assumption is a key difference between the method used in this analysis to estimate 

PM co-benefits and the methods used in analyses prior to EPA’s proposed Portland Cement 

NESHAP. The benefit-per-ton estimates now include incremental benefits down to the lowest 

modeled PM2.5 air quality levels. 

PM-related mortality provides the majority (85-95%) of the monetized value in each 

benefit-per-ton estimate. As such, EPA deems it important to characterize the uncertainty 

underlying the concentration-response (C-R) functions used in its benefits analyses of 

regulations affecting PM levels. EPA has investigated methods to characterize uncertainty in 

the relationship between PM2.5 exposure and premature mortality. EPA’s final PM2.5 NAAQS 

analysis provides a more complete picture about the overall uncertainty in PM2.5 benefits 

estimates. For more information, please consult the PM2.5 NAAQS RIA (Table 5.5). 

However, due to the limitations of the benefit-per-ton methodology employed here, the 

quantitative uncertainty analysis related to the C-R relationship between PM2.5 and premature 

mortality that EPA usually conducts in association with its benefits analysis was not 

conducted for this proposal. 

Typically, the premature mortality-related effect coefficients that underlie the benefitsper-ton estimates are drawn from epidemiology studies that examine two large population 

cohorts: the American Cancer Society cohort (Pope et al., 2002)234 and the Harvard Six Cities 

cohort (Laden et al., 2006).235 The concentration-response (C-R) function developed from the 

extended analysis of American Cancer Society (ACS) cohort, as reported in Pope et al. 

(2002), has previously been used by EPA to generate its primary benefits estimate. The 

extended analysis of the Harvard Six Cities cohort, as reported by Laden et al (2006), was 

published after the completion of the Staff Paper for the 2006 PM2.5 NAAQS and has been 

used as an alternative estimate in the PM2.5 NAAQS RIA and PM2.5 co-benefits estimates in 

analyses completed since the PM2.5 NAAQS. These are logical choices for anchor points 

when presenting PM-related benefits because, although both studies are well designed and 

peer reviewed, there are strengths and weaknesses inherent in each, which argues for using 

both studies to generate benefits estimates. Using the alternate relationships between PM2.5 

and premature mortality supplied by experts as part of EPA’s 206 Expert Elicitation Study,

higher and lower benefits estimates are plausible, but most of the expert-based estimates fall 

between the two epidemiology-based estimates (Roman et al., 2008; IEc, 2006).236,237 

However, due to the analytical limitations associated with this analysis, we have chosen to use 

the benefit-per-ton value derived from the ACS study and note that benefits would be 
Environmental and Health Impacts 

7-35 

approximately 145% (or nearly two-and-a-half times) larger if the Harvard Six Cities values 

were used. 

As a note to those who might be comparing the benefits estimates in this rule to those 

in previous EPA analyses, it is the nature of benefits analyses for assumptions and methods to 

evolve over time to reflect the most current interpretation of the scientific and economic 

literature. For a period of time (2004-2008), EPA’s Office of Air and Radiation (OAR) 

valued mortality risk reductions using a value of statistical life (VSL) estimate derived from a 

limited analysis of some of the available studies. OAR arrived at a VSL using a range of $1 

million to $10 million (2000$) consistent with two meta-analyses of the wage-risk literature. 

The $1 million value represented the lower end of the interquartile range from the Mrozek and 

Taylor (2002)238 meta-analysis of 33 studies. The $10 million value represented the upper 

end of the interquartile range from the Viscusi and Aldy (2003)239 meta-analysis of 43 studies. 

The mean estimate of $5.5 million (2000$) was also consistent with the mean VSL of $5.4 

million estimated in the Kochi et al. (2006)240 meta-analysis. However, the Agency neither 

changed its official guidance on the use of VSL in rule-makings nor subjected the interim 

estimate to a scientific peer-review process through the Science Advisory Board (SAB) or 

other peer-review group. 

Until updated guidance is available, EPA determined that a single, peer-reviewed 

estimate applied consistently best reflects the SAB-EEAC advice it has received. Therefore, 

EPA has decided to apply the VSL that was vetted and endorsed by the SAB in the Guidelines 

for Preparing Economic Analyses (U.S. EPA, 2000)241 while they continue efforts to update 

their guidance on this issue.P

 This approach calculates a mean value across VSL estimates 

derived from 26 labor market and contingent valuation studies published between 1974 and 

1991. The mean VSL across these studies is $6.3 million (2000$). The dollar-per-ton 

estimates used in this analysis are based on this VSL. 

The benefit-per-ton estimates are subject to a number of assumptions and 

uncertainties. 

 They do not reflect local variability in population density, meteorology, 

exposure, baseline health incidence rates, or other local factors that might lead 

to an overestimate or underestimate of the actual benefits of controlling fine 

particulates. EPA will conduct full-scale air quality modeling for the final 

rulemaking in an effort to capture this variability. Please refer to Section VII.E 

for a description of EPA’s modeling plans and to Section VIII.G.2 for the 

description of the quantification and monetization of health impacts for the 

FRM. 

 This analysis assumes that all fine particles, regardless of their chemical 

composition, are equally potent in causing premature mortality. This is an 

 P

 In the (draft) update of the Economic Guidelines (U.S. EPA, 2008c), EPA retained the VSL endorsed by the 

SAB with the understanding that further updates to the mortality risk valuation guidance would be forthcoming 

in the near future. Therefore, this report does not represent final agency policy. The draft update of the 

Economic Guidelines is available on the Internet at <http://yosemite.epa.gov/ee/epa/eermfile.nsf/vwAN/EE0516-01.pdf/$File/EE-0516-01.pdf>. 
Draft Regulatory Impact Analysis 

7-36 

important assumption, because PM2.5 produced via transported precursors 

emitted from stationary sources may differ significantly from direct PM2.5 

released from diesel engines and other industrial sources, but no clear scientific 

grounds exist for supporting differential effects estimates by particle type. 

 This analysis assumes that the health impact function for fine particles is linear 

within the range of ambient concentrations under consideration. Thus, the 

estimates include health benefits from reducing fine particles in areas with 

varied concentrations of PM2.5, including both regions that are in attainment 

with fine particle standard and those that do not meet the standard down to the 

lowest modeled concentrations. 

 There are several health benefits categories that we were unable to quantify 

due to limitations associated with using benefits-per-ton estimates, several of 

which could be substantial. Because the NOX and VOC emission reductions 

associated with this proposal are also precursors to ozone, reductions in NOX 

and VOC would also reduce ozone formation and the health effects associated 

with ozone exposure. Unfortunately, benefits-per-ton estimates do not exist 

due to issues associated with the complexity of the atmospheric air chemistry 

and nonlinearities associated with ozone formation. The PM-related benefitsper-ton estimates also do not include any human welfare or ecological benefits. 

Please refer to VIII.G.2 for a description of the quantification and monetization 

of health impact for the FRM and a description of the unquantified co-pollutant 

benefits associated with this rulemaking. 

 There are many uncertainties associated with the health impact functions used 

in this modeling effort. These include: within-study variability (the precision 

with which a given study estimates the relationship between air quality 

changes and health effects); across-study variation (different published studies 

of the same pollutant/health effect relationship typically do not report identical 

findings and in some instances the differences are substantial); the application 

of C-R functions nationwide (does not account for any relationship between 

region and health effect, to the extent that such a relationship exists); 

extrapolation of impact functions across population (we assumed that certain 

health impact functions applied to age ranges broader than that considered in 

the original epidemiological study); and various uncertainties in the C-R 

function, including causality and thresholds. These uncertainties may underor over-estimate benefits.

 EPA has investigated methods to characterize uncertainty in the relationship 

between PM2.5 exposure and premature mortality. EPA’s final PM2.5 NAAQS 

analysis provides a more complete picture about the overall uncertainty in 

PM2.5 benefits estimates. For more information, please consult the PM2.5 

NAAQS RIA (Table 5.5). 

 The benefit-per-ton estimates used in this analysis incorporate projections of 

key variables, including atmospheric conditions, source level emissions, 

population, health baselines and incomes, technology. These projections 

introduce some uncertainties to the benefit per ton estimates. 
Environmental and Health Impacts 

7-37 

 As described above, using the benefit-per-ton value derived from the ACS 

study (Pope et al., 2002) alone provides an incomplete characterization of 

PM2.5 benefits. When placed in the context of the Expert Elicitation results, 

this estimate falls toward the lower end of the distribution. By contrast, the 

estimated PM2.5 benefits using the coefficient reported by Laden in that 

author’s reanalysis of the Harvard Six Cities cohort fall toward the upper end 

of the Expert Elicitation distribution results. 

As mentioned above, emissions changes and benefits-per-ton estimates alone are not a 

good indication of local or regional air quality and health impacts, as there may be localized 

impacts associated with the proposed rulemaking. Additionally, the atmospheric chemistry 

related to ambient concentrations of PM2.5, ozone and air toxics is very complex. Full-scale 

photochemical modeling is therefore necessary to provide the needed spatial and temporal 

detail to more completely and accurately estimate the changes in ambient levels of these 

pollutants and their associated health and welfare impacts. As discussed above, timing and 

resource constraints precluded EPA from conducting a full-scale photochemical air quality 

modeling analysis in time for the NPRM. For the final rule, however, a national-scale air 

quality modeling analysis will be performed to analyze the impacts of the standards on PM2.5, 

ozone, and selected air toxics. The benefits analysis plan for the final rulemaking is discussed 

in the next section. 

7.3.2 Human Health and Environmental Benefits for the Final Rule 

7.3.2.1 Human Health and Environmental Impacts 

 To model the ozone and PM air quality benefits of the final rule, EPA will use the 

Community Multiscale Air Quality (CMAQ) model (see Section 7.2.3.1 for a description of 

the CMAQ model). The modeled ambient air quality data will serve as an input to the 

Environmental Benefits Mapping and Analysis Program (BenMAP).242 BenMAP is a 

computer program developed by EPA that integrates a number of the modeling elements used 

in previous RIAs (e.g., interpolation functions, population projections, health impact 

functions, valuation functions, analysis and pooling methods) to translate modeled air 

concentration estimates into health effects incidence estimates and monetized benefits 

estimates. 

Table 7-6 lists the co-pollutant health effect exposure-response functions we will use 

to quantify the co-pollutant incidence impacts associated with the final light-duty vehicles 

standard. 
Draft Regulatory Impact Analysis 

7-38 

Table 7-6: Health Impact Functions Used in BenMAP to Estimate Impacts of PM2.5 and Ozone Reductions 

ENDPOINT POLLUTANT STUDY STUDY POPULATION 

Premature Mortality 

Premature mortality – 

daily time series 

O3 Multi-city

Bell et al (2004) (NMMAPS study)243 – Nonaccidental 

Huang et al (2005)244 - Cardiopulmonary 

Schwartz (2005)245 – Non-accidental 

Meta-analyses:

Bell et al (2005)246 – All cause 

Ito et al (2005)247 – Non-accidental 

Levy et al (2005)248 – All cause 

All ages 

Premature mortality 

—cohort study, allcause 

PM2.5 Pope et al. (2002)249

Laden et al. (2006)250 >29 years 

>25 years 

Premature mortality, 

total exposures 

PM2.5 Expert Elicitation (IEc, 2006)251 >24 years 

Premature mortality 

— all-cause 

PM2.5 Woodruff et al. (1997)252 Infant (<1 year) 

Chronic Illness 

Chronic bronchitis PM2.5 Abbey et al. (1995)253 >26 years 

Nonfatal heart attacks PM2.5 Peters et al. (2001)254 Adults (>18 years) 

Hospital Admissions 

Pooled estimate: 

Schwartz (1995) - ICD 460-519 (all resp)255

Schwartz (1994a; 1994b) - ICD 480-486 

(pneumonia)256,257 

Moolgavkar et al. (1997) - ICD 480-487 

(pneumonia)258

Schwartz (1994b) - ICD 491-492, 494-496 

(COPD) 

Moolgavkar et al. (1997) – ICD 490-496 

(COPD) 

>64 years 

O3 

Burnett et al. (2001)259 <2 years 

PM2.5 Pooled estimate:

Moolgavkar (2003)—ICD 490-496 (COPD)260

Ito (2003)—ICD 490-496 (COPD)261

>64 years 

PM2.5 Moolgavkar (2000)—ICD 490-496 (COPD)262 20–64 years 

PM2.5 Ito (2003)—ICD 480-486 (pneumonia) >64 years 

RespirFSatory 

PM2.5 Sheppard (2003)—ICD 493 (asthma)263 <65 years 

PM2.5 Pooled estimate: 

Moolgavkar (2003)—ICD 390-429 (all 

cardiovascular) 

Ito (2003)—ICD 410-414, 427-428 (ischemic 

heart disease, dysrhythmia, heart failure) 

Cardiovascular >64 years 

PM2.5 Moolgavkar (2000)—ICD 390-429 (all 

cardiovascular) 

20–64 years 
Environmental and Health Impacts 

7-39 

Asthma-related ER 

visits 

O3 Pooled estimate:

Jaffe et al (2003)264

Peel et al (2005)265

Wilson et al (2005)266

5–34 years 

All ages 

All ages 

Asthma-related ER 

visits (con’t) 

PM2.5 Norris et al. (1999)267 0–18 years 

Other Health Endpoints 

Acute bronchitis PM2.5 Dockery et al. (1996)268 8–12 years 

Upper respiratory 

symptoms 

PM2.5 Pope et al. (1991)269 Asthmatics, 9–11 

years 

Lower respiratory 

symptoms 

PM2.5 Schwartz and Neas (2000)270 7–14 years 

Asthma exacerbations PM2.5 Pooled estimate: 

Ostro et al. (2001)271 (cough, wheeze and 

shortness of breath) 

Vedal et al. (1998)272 (cough) 

6–18 yearsa

Work loss days PM2.5 Ostro (1987)273 18–65 years 

School absence days 

O3 

Pooled estimate:

Gilliland et al. (2001)274

Chen et al. (2000)275

5–17 yearsb

O3 Ostro and Rothschild (1989)276 Minor Restricted 18–65 years 

Activity Days 

(MRADs) 

PM2.5 Ostro and Rothschild (1989) 18–65 years 

Notes: 

a

 The original study populations were 8 to 13 for the Ostro et al. (2001) study and 6 to 13 for the Vedal et al. 

(1998) study. Based on advice from the Science Advisory Board Health Effects Subcommittee (SAB-HES), we 

extended the applied population to 6 to 18, reflecting the common biological basis for the effect in children in 

the broader age group. See: U.S. Science Advisory Board. 2004. Advisory Plans for Health Effects Analysis in 

the Analytical Plan for EPA’s Second Prospective Analysis –Benefits and Costs of the Clean Air Act, 1990—

2020. EPA-SAB-COUNCIL-ADV-04-004. See also National Research Council (NRC). 2002. Estimating the 

Public Health Benefits of Proposed Air Pollution Regulations. Washington, DC: The National Academies 

Press. 

b

 Gilliland et al. (2001) studied children aged 9 and 10. Chen et al. (2000) studied children 6 to 11. Based on 

recent advice from the National Research Council and the EPA SAB-HES, we have calculated reductions in 

school absences for all school-aged children based on the biological similarity between children aged 5 to 17. 

7.3.2.2 Monetized Estimates of Impacts of Reductions in Co-Pollutants 

Table 7-7 presents the monetary values we will apply to changes in the incidence of 

health and welfare effects associated with reductions in non-GHG pollutants that will occur 

when these GHG control strategies are finalized. 
Draft Regulatory Impact Analysis 

7-40 

Table 7-7: Valuation Metrics Used in BenMAP to Estimate Monetary Co-Benefits 

Endpoint Valuation Method 

Valuation

(2000$) 

Premature mortality Assumed Mean VSL $6,300,000 

Chronic Illness 

 Chronic Bronchitis WTP: Average Severity $340,482 

 Myocardial Infarctions, Nonfatal Medical Costs Over 5 Years. Varies by 

age and discount rate. Russell 

(1998)277

--- 

 Medical Costs Over 5 Years. Varies by 

age and discount rate. Wittels 

(1990)278

--- 

Hospital Admissions 

 Respiratory, Age 65+ COI: Medical Costs + Wage Lost $18,353 

 Respiratory, Ages 0-2 COI: Medical Costs $7,741 

 Chronic Lung Disease (less 

 Asthma) 

COI: Medical Costs + Wage Lost $12,378 

 Pneumonia COI: Medical Costs + Wage Lost $14,693 

 Asthma COI: Medical Costs + Wage Lost $6,634 

 Cardiovascular COI: Medical Costs + Wage Lost (20-

64) 

$22,778 

COI: Medical Costs + Wage Lost (65-

99) 

$21,191 

ER Visits, Asthma COI: Smith et al. (1997)279 $312 

COI: Standford et al. (1999)280 $261 

Other Health Endpoints 

 Acute Bronchitis WTP: 6 Day Illness, CV Studies $356 

 Upper Respiratory Symptoms WTP: 1 Day, CV Studies $25 

 Lower Respiratory Symptoms WTP: 1 Day, CV Studies $16 

 Asthma Exacerbation WTP: Bad Asthma Day, Rowe and 

Chestnut (1986) 281

$43 

 Work Loss Days Median Daily Wage, County-Specific --- 

 Minor Restricted Activity Days WTP: 1 Day, CV Studies $51 

 School Absence Days Median Daily Wage, Women 25+ $75 

 Worker Productivity Median Daily Wage, Outdoor 

Workers, County-Specific 

--- 

Environmental Endpoints 

 Recreational Visibility WTP: 86 Class I Areas --- 

Source: Dollar amounts for each valuation method were extracted from BenMAP version 3.0. 

7.3.2.3 Other Unquantified Health and Environmental Impacts 

 In addition to the co-pollutant health and environmental impacts we will quantify for 

the analysis of the Light-Duty Vehicle GHG standard, there are a number of other health and 

human welfare endpoints that we will not be able to quantify because of current limitations in 

the methods or available data. These impacts are associated with emissions of air toxics 

(including benzene, 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, and ethanol), 

ambient ozone, and ambient PM2.5 exposures. For example, we have not quantified a number 

of known or suspected health effects linked with ozone and PM for which appropriate health 

impact functions are not available or which do not provide easily interpretable outcomes (i.e., 
Environmental and Health Impacts 

7-41 

changes in heart rate variability). In addition, we are currently unable to quantify a number 

of known welfare effects, including reduced acid and particulate deposition damage to 

cultural monuments and other materials, and environmental benefits due to reductions of 

impacts of eutrophication in coastal areas. For air toxics, the available tools and methods to 

assess risk from mobile sources at the national scale are not adequate for extrapolation to 

benefits assessment. In addition to inherent limitations in the tools for national-scale 

modeling of air toxics and exposure, there is a lack of epidemiology data for air toxics in the 

general population. Table 7-8 lists these unquantified health and environmental impacts. 

Table 7-8: Unquantified and Non-Monetized Potential Effects

POLLUTANT/EFFECTS EFFECTS NOT INCLUDED IN ANALYSIS - CHANGES IN: 

Ozone Healtha Chronic respiratory damage 

Premature aging of the lungs 

Non-asthma respiratory emergency room visits 

Exposure to UVb (+/-)d

Ozone Welfare Yields for 

-commercial forests 

-some fruits and vegetables 

-non-commercial crops 

Damage to urban ornamental plants 

Impacts on recreational demand from damaged forest aesthetics 

Ecosystem functions 

Exposure to UVb (+/-) 

PM Healthb Premature mortality - short term exposuresc

Low birth weight 

Pulmonary function 

Chronic respiratory diseases other than chronic bronchitis 

Non-asthma respiratory emergency room visits 

Exposure to UVb (+/-) 

PM Welfare Residential and recreational visibility in non-Class I areas 

Soiling and materials damage 

Damage to ecosystem functions 

Exposure to UVb (+/-) 

Nitrogen and Sulfate 

Deposition Welfare 

Commercial forests due to acidic sulfate and nitrate deposition 

Commercial freshwater fishing due to acidic deposition 

Recreation in terrestrial ecosystems due to acidic deposition 

Existence values for currently healthy ecosystems 

Commercial fishing, agriculture, and forests due to nitrogen deposition 

Recreation in estuarine ecosystems due to nitrogen deposition 

Ecosystem functions 

Passive fertilization 

CO Health Behavioral effects 

Hydrocarbon (HC)/Toxics 

Healthe Cancer (benzene, 1,3-butadiene, formaldehyde, acetaldehyde, ethanol) 

Anemia (benzene) 

Disruption of production of blood components (benzene) 

Reduction in the number of blood platelets (benzene) 

Excessive bone marrow formation (benzene) 

Depression of lymphocyte counts (benzene) 

Reproductive and developmental effects (1,3-butadiene, ethanol) 

Irritation of eyes and mucus membranes (formaldehyde) 

Respiratory irritation (formaldehyde) 

Asthma attacks in asthmatics (formaldehyde) 
Draft Regulatory Impact Analysis 

7-42 

Asthma-like symptoms in non-asthmatics (formaldehyde) 

Irritation of the eyes, skin, and respiratory tract (acetaldehyde) 

Upper respiratory tract irritation and congestion (acrolein) 

HC/Toxics Welfaref Direct toxic effects to animals 

Bioaccumulation in the food chain 

Damage to ecosystem function 

Odor 

a

 In addition to primary economic endpoints, there are a number of biological responses that have been 

associated with ozone health effects including increased airway responsiveness to stimuli, inflammation in the 

lung, acute inflammation and respiratory cell damage, and increased susceptibility to respiratory infection. The 

public health impact of these biological responses may be partly represented by our quantified endpoints. 

b

 In addition to primary economic endpoints, there are a number of biological responses that have been 

associated with PM health effects including morphological changes and altered host defense mechanisms. The 

public health impact of these biological responses may be partly represented by our quantified endpoints. c

 While some of the effects of short-term exposures are likely to be captured in the estimates, there may be 

premature mortality due to short-term exposure to PM not captured in the cohort studies used in this analysis. 

However, the PM mortality results derived from the expert elicitation do take into account premature mortality 

effects of short term exposures. 

d

 May result in benefits or disbenefits. 

e

 Many of the key hydrocarbons related to this rule are also hazardous air pollutants listed in the Clean Air Act. Please refer to Chapter 8.4 for additional information on the health effects of air toxics. 

f

 Please refer to Chapter 8.4 for additional information on the welfare effects of air toxics. 

In addition to the co-pollutant health and environmental impacts we will quantify for 

the analysis of the final standard, there are a number of other health and human welfare 

endpoints that we will not be able to quantify or monetize because of current limitations in the 

methods or available data. These impacts are associated with emissions of air toxics 

(including benzene, 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, and ethanol), 

ambient ozone, and ambient PM2.5 exposures. Chapter 7.3 of the RIA lists these unquantified 

health and environmental impacts. 

While there will be impacts associated with air toxic pollutant emission changes that 

result from the final standard, we will not attempt to monetize those impacts. This is 

primarily because currently available tools and methods to assess air toxics risk from mobile 

sources at the national scale are not adequate for extrapolation to incidence estimations or 

benefits assessment. The best suite of tools and methods currently available for assessment at 

the national scale are those used in the National-Scale Air Toxics Assessment (NATA). The 

EPA Science Advisory Board specifically commented in their review of the 1996 NATA that 

these tools were not yet ready for use in a national-scale benefits analysis, because they did 

not consider the full distribution of exposure and risk, or address sub-chronic health effects.282 

While EPA has since improved the tools, there remain critical limitations for estimating 

incidence and assessing benefits of reducing mobile source air toxics. EPA continues to work 

to address these limitations; however, we do not anticipate having methods and tools available 
Environmental and Health Impacts 

7-43 

for national-scale application in time for the analysis of the final rules.Q 

7.4 Changes in Global Mean Temperature and Sea-Level Rise Associated 

with the Proposal’s GHG Emissions Reductions 

7.4.1 Introduction 

 Based on modeling analysis performed by the EPA, reductions in CO2 and other 

GHGs associated with the Proposal will affect climate change projections. Because GHGs 

mix well in the atmosphere and have long atmospheric lifetimes, changes in GHG emissions 

will affect atmospheric concentrations of greenhouse gases and future climate for decades to 

centuries. Two common indicators of climate change are global mean surface temperature and 

sea-level rise. This section estimates the response in global mean surface temperature and sealevel rise projections to the estimated net global GHG emissions reductions associated with 

the Proposal (see Chapter 5 for the estimated net reductions in global emissions over time by 

GHG). 

7.4.2 Estimated Projected Reductions in Global Mean Surface Temperature and 

Sea-Level Rise 

 We estimated changes in projected atmospheric CO2 concentrations, global mean 

surface temperature and sea-level rise to 2100 using the MiniCAM (Mini Climate Assessment 

Model) integrated assessment model283 coupled with the MAGICC (Model for the 

Assessment of Greenhouse-gas Induced Climate Change) simple climate model.284 MiniCAM 

was used to create the globally and temporally consistent set of climate relevant variables 

required for running MAGICC. MAGICC was then used to estimate the change in the 

atmospheric CO2 concentrations, global mean surface temperature and sea-level rise over 

time. Given the magnitude of the estimated emissions reductions associated with the rule, a 

simple climate model such as MAGICC is reasonable for estimating the atmospheric and 

climate response. 

An emissions scenario for the proposal was developed by applying the proposal’s 

estimated emissions reductions to the MiniCAM reference (no climate policy or baseline) 

scenario (used as the basis for the Representative Concentration Pathway RCP4.5285). 

Specifically, the CO2, N2O, CH4, and HFC-134a emissions reductions from Chapter 5 were 

 

Q In April, 2009, EPA hosted a workshop on estimating the benefits or reducing hazardous air 

pollutants. This workshop built upon the work accomplished in the June 2000 Science Advisory Board/EPA 

Workshop on the Benefits of Reductions in Exposure to Hazardous Air Pollutants, which generated thoughtful 

discussion on approaches to estimating human health benefits from reductions in air toxics exposure, but no 

consensus was reached on methods that could be implemented in the near term for a broad selection of air toxics. 

Please visit http://epa.gov/air/toxicair/2009workshop.html for more information about the workshop and its 

associated materials. 
Draft Regulatory Impact Analysis 

7-44 

applied as net reductions to the MiniCAM global baseline net emissions for each GHG. All 

emissions reductions were assumed to begin in 2012, with zero emissions change in 2011 and 

linearly increasing to equal the value supplied (in Chapter 5) for 2020. The emissions 

reductions past 2050 were scaled with total U.S. road transportation fuel consumption from 

the MiniCAM reference scenario. Using MAGICC, the atmospheric CO2 concentration, the 

global mean temperature, and sea-level change were projected at five-year time steps to 2100 

for both the reference (no climate policy) scenario and the emissions scenario specific to the 

Proposal. To capture some of the uncertainty in the climate system, the changes in projected 

temperatures and sea level were estimated across the most current Intergovernmental Panel on 

Climate Change (IPCC) range of climate sensitivities, 1.5°C to 6.0°C.286 

To compute the reductions in atmospheric CO2 concentration, temperature, and sealevel rise specifically attributable to the Proposal, the output from the Proposal’s emissions 

scenario was subtracted from the reference (no policy or baseline) emissions case scenario. 

As a result of the Proposal’s emissions reductions, the atmospheric CO2 concentration is 

projected to be reduced by approximately 2.9 to 3.2 parts per million (ppm), the global mean 

temperature is projected to be reduced by approximately 0.007-0.016°C by 2100 and global 

mean sea-level rise is projected to be reduced by approximately 0.06-0.15 cm by 2100. 

Figure 7-4 provides the estimated reductions in projected global mean surface 

temperatures associated with the Proposal. Figure 7-5 provides the estimated reductions in 

global mean sea-level rise associated with the Proposal. 

Global Mean Temperature Change

-0.0200

-0.0150

-0.0100

-0.0050

0.0000

2000 2050 2100

Year

Difference (°C)

ClimSens=1.5

ClimSens=2.0

ClimSens=2.5

ClimSens=3.0

ClimSens=4.5

ClimSens=6.0

Figure 7-4 Estimated Projected Reductions in Global Mean Surface Temperatures from Baseline for the 

Proposed Vehicles Rulemaking (for climate sensitivities ranging from 1.5-6°C) 
Environmental and Health Impacts 

7-45 

Global Mean Sea Level Rise Change

-0.20

-0.15

-0.10

-0.05

0.00

2000 2050 2100

Year

Difference (cm)

ClimSens=1.5

ClimSens=2.0

ClimSens=2.5

ClimSens=3.0

ClimSens=4.5

ClimSens=6.0

Figure 7-5 Estimated Projected Reductions in Global Mean Sea-Level Rise from Baseline for the 

Proposed Vehicles Rulemaking (for climate sensitivities ranging from 1.5-6°C) 

The results in both Figure 7-4 and Figure 7-5 show a relatively small reduction in the 

projected global mean surface temperature and sea level respectively, across all climate 

sensitivities. The projected reductions are small relative to the IPCC’s 2100 “best estimates” 

for global mean temperature increases (1.8 – 4.0oC) and sea-level rise (0.20-0.59m) for all 

global GHG emissions sources for a range of emissions scenarios.287 These projected 

reductions are proportionally representative of changes to U.S. GHG emissions in the 

transportation sector. While not formally estimated for the proposed rulemaking, a reduction 

in projected global mean temperature and sea-level rise implies a reduction in the risks 

associated with of climate change. Both figures illustrate that the distribution for projected 

global mean temperature and sea-level rise increases has shifted down. The benefits of GHG 

emissions reductions can be characterized both qualitatively and quantitatively, some of 

which can be monetized (seeChapter 7.5). There are substantial uncertainties in modeling the 

global risks of climate change, which complicates quantification and benefit-cost assessments. 

Changes in climate variables are a meaningful proxy for changes in the risk of all potential 

impacts--including those that can be monetized, and those that have not been monetized but 

can be quantified in physical terms (e.g., water availability), as well as those that have not yet 

been quantified or are extremely difficult to quantify (e.g., respectively forest disturbance and 

catastrophic events such as collapse of large ice sheets and subsequent sea-level rise). 
Draft Regulatory Impact Analysis 

7-46 

7.5 SCC and GHG Benefits 

We assigned a monetary value to reductions in CO2 emissions using the marginal 

dollar value (i.e., cost) of climate-related damages resulting from carbon emissions, also 

referred to as “social cost of carbon” (SCC). The SCC is intended to measure the monetary 

value society places on impacts resulting from increased GHGs, such as property damage 

from sea level rise, forced migration due to dry land loss, and mortality changes associated 

with vector-borne diseases. Published estimates of the SCC vary widely, however, as a result 

of uncertainties about future economic growth, climate sensitivity to GHG emissions, 

procedures used to model the economic impacts of climate change, and the choice of discount 

rates. Furthermore, some of the likely and potential damages from climate change—for 

example, the loss of endangered species—are generally not included in current SCC 

estimates. These omissions may turn out to be significant, in the sense that they may mean 

that the best current estimates are too low. As noted by the IPCC Fourth Assessment Report, 

“It is very likely that globally aggregated figures underestimate the damage costs because they 

cannot include many non-quantifiable impacts."288 

Today’s joint proposals present a set of interim SCC values reflecting a federal 

interagency group’s interpretation of the relevant climate economics literature. The interim 

SCC values, which reflect an interim interpretation of the current literature, are derived using 

several discount rates. The interim SCC values include: 

 $5 (based on a 5% discount rate); 

 $10(5% using Newell-Pizer adjustment);, 

 $20(average SCC value from the average SCC estimates based on 5% and 

3%); 

 $34 (3%); 

 $56 (3% using Newell-Pizer adjustment). 

These interim SCC values are in 2007 dollars, and are based on a CO2 emissions 

change of 1 metric ton in 2007. Section III.H.6 of the Preamble provides a complete 

discussion about SCC and the interim set of values. 

The tables below summarize the total GHG benefits for the lifetime of the rule, which 

are calculated by using the five interim SCC values. Specifically, total monetized benefits in 

each year are calculated by multiplying the marginal benefits estimates per metric ton of CO2

(the SCC) by the reductions in CO2 for that year. We have also approximated the total 

monetized benefits for non-CO2 GHGs by multiplying the SCC value by the reductions in 

non-CO2 GHGs for that year. Marginal benefit estimates per metric ton of non-CO2 GHGs 

are currently unavailable, but work is on-going to monetize benefits related to the mitigation 

of other non-CO2 GHGs. 
Environmental and Health Impacts 

7-47 

Table 7-9: Upstream and Downstream CO2 Benefits for the Given SCC Value, Calendar Year Analysis (Millions of 

2007 dollars) 

YEAR 5% 

5% 

NEWELLPIZER 

FROM 3% 

AND 5% 3% 

3% 

NEWELLPIZER 

2012 $35 $70 $132 $230 $383 

2013 $89 $179 $340 $590 $984 

2014 $168 $336 $639 $1,109 $1,849 

2015 $281 $562 $1,068 $1,855 $3,092 

2016 $439 $878 $1,668 $2,898 $4,829 

2017 $601 $1,203 $2,285 $3,968 $6,614 

2018 $768 $1,536 $2,919 $5,069 $8,449 

2019 $939 $1,878 $3,568 $6,197 $10,328 

2020 $1,112 $2,225 $4,227 $7,342 $12,237 

2021 $1,288 $2,577 $4,896 $8,503 $14,172 

2022 $1,465 $2,929 $5,566 $9,666 $16,111 

2023 $1,645 $3,290 $6,250 $10,855 $18,092 

2024 $1,827 $3,654 $6,942 $12,057 $20,095 

2025 $2,014 $4,027 $7,652 $13,290 $22,151 

2026 $2,200 $4,400 $8,359 $14,519 $24,198 

2027 $2,386 $4,772 $9,067 $15,748 $26,247 

2028 $2,568 $5,136 $9,759 $16,949 $28,249 

2029 $2,749 $5,497 $10,445 $18,141 $30,235 

2030 $2,931 $5,861 $11,137 $19,342 $32,237 

2031 $3,117 $6,234 $11,844 $20,571 $34,285 

2032 $3,306 $6,611 $12,562 $21,818 $36,363 

2033 $3,501 $7,002 $13,305 $23,108 $38,513 

2034 $3,702 $7,404 $14,068 $24,434 $40,723 

2035 $3,912 $7,824 $14,865 $25,819 $43,031 

2036 $4,129 $8,258 $15,691 $27,253 $45,421 

2037 $4,357 $8,715 $16,558 $28,758 $47,930 

2038 $4,594 $9,188 $17,458 $30,322 $50,536 

2039 $4,844 $9,687 $18,406 $31,969 $53,281 

2040 $5,104 $10,209 $19,396 $33,688 $56,147 

2041 $5,379 $10,758 $20,441 $35,502 $59,170 

2042 $5,668 $11,336 $21,539 $37,409 $62,349 

2043 $5,973 $11,945 $22,696 $39,420 $65,700 

2044 $6,294 $12,587 $23,916 $41,538 $69,229 

2045 $6,632 $13,263 $25,200 $43,768 $72,947 

2046 $6,987 $13,975 $26,552 $46,117 $76,861 

2047 $7,362 $14,724 $27,976 $48,590 $80,983 

2048 $7,756 $15,512 $29,473 $51,191 $85,318 

2049 $8,171 $16,342 $31,049 $53,927 $89,878 

2050 $8,607 $17,214 $32,706 $56,805 $94,675 

NPV, 3% $62,100 $124,200 $236,000 $409,800 $683,100

NPV, 7% $25,600 $51,200 $97,200 $168,800 $281,300
Draft Regulatory Impact Analysis 

7-48 

Table 7-10: Upstream and Downstream non-CO2 GHG Benefits for the Given SCC Value, Calendar Year Analysis 

(Millions of 2007 dollars) 

YEAR 5% 

5% 

NEWELLPIZER 

FROM 3% 

AND 5% 3% 

3% 

NEWELLPIZER 

2012 $5 $11 $21 $36 $60 

2013 $13 $27 $51 $88 $147 

2014 $24 $48 $91 $158 $263 

2015 $38 $76 $145 $252 $419 

2016 $55 $109 $208 $361 $601 

2017 $72 $144 $274 $476 $793 

2018 $91 $181 $344 $597 $996 

2019 $110 $220 $417 $725 $1,208 

2020 $133 $266 $506 $879 $1,465 

2021 $154 $308 $585 $1,016 $1,694 

2022 $175 $351 $667 $1,158 $1,929 

2023 $198 $395 $751 $1,304 $2,173 

2024 $220 $440 $837 $1,453 $2,422 

2025 $243 $487 $925 $1,606 $2,677 

2026 $267 $533 $1,013 $1,760 $2,934 

2027 $290 $580 $1,102 $1,913 $3,189 

2028 $313 $626 $1,189 $2,064 $3,441 

2029 $334 $668 $1,269 $2,204 $3,674 

2030 $358 $716 $1,361 $2,364 $3,940 

2031 $379 $758 $1,441 $2,503 $4,172 

2032 $400 $801 $1,521 $2,642 $4,403 

2033 $422 $843 $1,602 $2,782 $4,637 

2034 $443 $886 $1,683 $2,924 $4,873 

2035 $465 $930 $1,766 $3,067 $5,112 

2036 $487 $974 $1,851 $3,214 $5,357 

2037 $510 $1,019 $1,937 $3,364 $5,607 

2038 $533 $1,066 $2,025 $3,517 $5,862 

2039 $557 $1,114 $2,116 $3,675 $6,124 

2040 $581 $1,163 $2,209 $3,836 $6,394 

2041 $607 $1,214 $2,306 $4,005 $6,676 

2042 $633 $1,267 $2,407 $4,180 $6,967 

2043 $661 $1,321 $2,511 $4,361 $7,268 

2044 $689 $1,378 $2,619 $4,548 $7,580 

2045 $719 $1,437 $2,730 $4,742 $7,904 

2046 $749 $1,498 $2,846 $4,944 $8,240 

2047 $781 $1,561 $2,967 $5,153 $8,588 

2048 $814 $1,627 $3,091 $5,369 $8,949 

2049 $847 $1,695 $3,220 $5,593 $9,322 

2050 $883 $1,765 $3,354 $5,826 $9,710 

NPV, 3% $7,100 $14,200 $27,100 $47,000 $78,400

NPV, 7% $3,000 $6,000 $11,400 $19,700 $32,900
Environmental and Health Impacts 

7-49 

Table 7-11: Upstream and Downstream CO2-Equivalent Benefits for the Given SCC Value, Calendar Year Analysis 

(Millions of 2007 dollars) 

YEAR 5% 

5% 

NEWELLPIZER 

FROM 3% 

AND 5% 3% 

3% 

NEWELLPIZER 

2012 $40 $81 $153 $266 $443 

2013 $103 $206 $391 $678 $1,131 

2014 $192 $384 $729 $1,267 $2,112 

2015 $319 $638 $1,213 $2,107 $3,511 

2016 $494 $987 $1,876 $3,258 $5,430 

2017 $673 $1,347 $2,559 $4,444 $7,407 

2018 $859 $1,717 $3,263 $5,667 $9,444 

2019 $1,049 $2,098 $3,985 $6,922 $11,537 

2020 $1,246 $2,491 $4,734 $8,222 $13,703 

2021 $1,442 $2,885 $5,481 $9,520 $15,866 

2022 $1,640 $3,280 $6,232 $10,824 $18,040 

2023 $1,842 $3,685 $7,001 $12,159 $20,265 

2024 $2,047 $4,094 $7,779 $13,510 $22,517 

2025 $2,257 $4,514 $8,577 $14,897 $24,828 

2026 $2,466 $4,933 $9,373 $16,279 $27,131 

2027 $2,676 $5,352 $10,169 $17,661 $29,435 

2028 $2,881 $5,762 $10,947 $19,014 $31,690 

2029 $3,083 $6,165 $11,714 $20,345 $33,909 

2030 $3,289 $6,578 $12,498 $21,707 $36,178 

2031 $3,496 $6,992 $13,285 $23,074 $38,457 

2032 $3,706 $7,412 $14,083 $24,460 $40,766 

2033 $3,923 $7,845 $14,906 $25,890 $43,150 

2034 $4,145 $8,290 $15,751 $27,357 $45,595 

2035 $4,377 $8,753 $16,631 $28,886 $48,143 

2036 $4,616 $9,232 $17,541 $30,467 $50,778 

2037 $4,867 $9,734 $18,494 $32,122 $53,537 

2038 $5,127 $10,254 $19,483 $33,839 $56,398 

2039 $5,400 $10,801 $20,522 $35,643 $59,405 

2040 $5,686 $11,371 $21,605 $37,525 $62,541 

2041 $5,986 $11,972 $22,747 $39,507 $65,846 

2042 $6,301 $12,603 $23,945 $41,589 $69,315 

2043 $6,633 $13,267 $25,207 $43,781 $72,968 

2044 $6,983 $13,965 $26,534 $46,086 $76,809 

2045 $7,350 $14,700 $27,930 $48,510 $80,851 

2046 $7,736 $15,473 $29,398 $51,060 $85,101 

2047 $8,143 $16,286 $30,943 $53,743 $89,571 

2048 $8,570 $17,139 $32,565 $56,560 $94,267 

2049 $9,018 $18,036 $34,269 $59,520 $99,201 

2050 $9,490 $18,979 $36,060 $62,631 $104,385 

NPV, 3% $69,200 $138,400 $263,000 $456,900 $761,400

NPV, 7% $28,600 $57,100 $108,500 $188,500 $314,200

EPA also conducted a separate analysis of the GHG benefits over the model year 

lifetimes of the 2012 through 2016 model year vehicles. In contrast to the calendar year 
Draft Regulatory Impact Analysis 

7-50 

analysis, the model year lifetime analysis shows the lifetime impacts of the program on each 

of these MY fleets over the course of its lifetime. Full details of the inputs to this analysis can 

be found in DRIA chapter 5. The GHG benefits of the full life of each of the five model years 

from 2012 through 2016 are shown in Table 7-12 through Table 7-16 for each of the five 

different social cost of carbon values. The GHG benefits are shown for each year in the 

model year life and in net present value using both a 3 percent and a 7 percent discount rate. 
Environmental and Health Impacts 

7-51 

Table 7-12: Upstream and Downstream CO2-Equivalent Benefits for the 5% SCC Value, Model Year Analysis 

(Millions of 2007 dollars) 

YEAR 2012 2013 2014 2015 2016 SUM 

2012 $42 $0 $0 $0 $0 $42

2013 $42 $67 $0 $0 $0 $109

2014 $42 $66 $95 $0 $0 $204

2015 $42 $66 $95 $137 $0 $340

2016 $41 $66 $95 $137 $188 $526

2017 $40 $65 $94 $136 $187 $522

2018 $39 $63 $92 $135 $187 $516

2019 $37 $61 $90 $133 $185 $507

2020 $36 $59 $88 $130 $182 $494

2021 $34 $56 $84 $126 $178 $478

2022 $32 $53 $80 $121 $172 $459

2023 $29 $50 $76 $115 $166 $436

2024 $25 $46 $71 $109 $158 $409

2025 $21 $40 $65 $102 $150 $378

2026 $18 $34 $57 $94 $140 $341

2027 $15 $28 $48 $81 $128 $300

2028 $12 $23 $40 $69 $112 $257

2029 $10 $19 $34 $58 $95 $216

2030 $8 $16 $28 $49 $80 $181

2031 $7 $13 $23 $40 $67 $150

2032 $5 $11 $19 $33 $56 $124

2033 $5 $9 $16 $28 $46 $103

2034 $4 $8 $13 $23 $38 $85

2035 $3 $6 $11 $19 $31 $71

2036 $3 $5 $9 $16 $26 $60

2037 $2 $5 $8 $14 $22 $51

2038 $2 $4 $7 $12 $19 $43

2039 $1 $3 $6 $10 $16 $37

2040 $1 $3 $4 $9 $14 $31

2041 $1 $2 $4 $6 $12 $26

2042 $1 $2 $4 $6 $9 $21

2043 $1 $2 $3 $5 $8 $19

2044 $1 $2 $3 $5 $7 $17

2045 $1 $2 $3 $4 $6 $15

2046 $1 $1 $2 $4 $6 $14

2047 $1 $1 $2 $3 $5 $12

2048 $0 $1 $2 $3 $5 $11

2049 $0 $0 $2 $3 $4 $8

2050 $0 $0 $0 $2 $4 $6

NPV, 

3% $477 $733 $1,021 $1,426 $1,897 $5,555

NPV, 

7% $368 $543 $727 $978 $1,251 $3,866
Draft Regulatory Impact Analysis 

7-52 

Table 7-13: Upstream and Downstream CO2-Equivalent Benefits for the 5% Newell-Pizer SCC Value, Model Year 

Analysis (Millions of 2007 dollars) 

YEAR 2012 2013 2014 2015 2016 SUM 

2012 $84 $0 $0 $0 $0 $84

2013 $84 $133 $0 $0 $0 $217

2014 $84 $133 $191 $0 $0 $407

2015 $83 $133 $190 $274 $0 $680

2016 $82 $131 $190 $273 $376 $1,052

2017 $80 $129 $187 $273 $374 $1,044

2018 $78 $126 $185 $270 $374 $1,033

2019 $75 $122 $180 $266 $370 $1,013

2020 $71 $118 $175 $260 $364 $988

2021 $68 $112 $168 $252 $356 $956

2022 $64 $107 $160 $242 $345 $918

2023 $58 $100 $152 $231 $332 $872

2024 $50 $91 $142 $219 $316 $818

2025 $42 $79 $130 $205 $300 $756

2026 $35 $67 $113 $187 $280 $683

2027 $29 $56 $96 $163 $256 $601

2028 $24 $47 $81 $139 $223 $513

2029 $20 $39 $68 $116 $190 $432

2030 $16 $32 $56 $97 $160 $361

2031 $13 $26 $47 $81 $133 $300

2032 $11 $22 $38 $67 $111 $249

2033 $9 $18 $32 $55 $92 $206

2034 $8 $15 $26 $46 $76 $171

2035 $7 $13 $22 $38 $63 $142

2036 $5 $11 $19 $32 $52 $120

2037 $5 $9 $16 $27 $44 $102

2038 $3 $8 $14 $23 $37 $86

2039 $3 $6 $12 $20 $32 $73

2040 $3 $5 $9 $17 $28 $62

2041 $2 $5 $8 $13 $24 $52

2042 $2 $4 $7 $12 $18 $43

2043 $2 $4 $6 $10 $16 $38

2044 $2 $3 $6 $9 $14 $35

2045 $2 $3 $5 $8 $13 $31

2046 $1 $3 $5 $7 $12 $28

2047 $1 $2 $4 $7 $10 $25

2048 $0 $2 $4 $6 $9 $21

2049 $0 $0 $3 $5 $8 $17

2050 $0 $0 $0 $5 $7 $12

NPV, 

3% $955 $1,467 $2,042 $2,853 $3,794 $11,109

NPV, 

7% $736 $1,086 $1,453 $1,955 $2,503 $7,733
Environmental and Health Impacts 

7-53 

Table 7-14: Upstream and Downstream CO2-Equivalent Benefits for the from 3% and 5% SCC Value, Model Year 

Analysis (Millions of 2007 dollars) 

YEAR 2012 2013 2014 2015 2016 SUM 

2012 $160 $0 $0 $0 $0 $160

2013 $160 $253 $0 $0 $0 $413

2014 $160 $252 $362 $0 $0 $774

2015 $158 $252 $361 $521 $0 $1,292

2016 $156 $249 $360 $519 $714 $1,998

2017 $152 $245 $356 $519 $711 $1,984

2018 $148 $240 $351 $513 $711 $1,962

2019 $142 $233 $343 $505 $702 $1,925

2020 $136 $224 $333 $493 $692 $1,878

2021 $129 $213 $320 $479 $676 $1,816

2022 $121 $203 $304 $460 $655 $1,743

2023 $110 $190 $289 $438 $630 $1,657

2024 $95 $173 $270 $416 $600 $1,555

2025 $81 $150 $247 $389 $569 $1,436

2026 $67 $128 $215 $355 $532 $1,298

2027 $56 $107 $183 $309 $487 $1,141

2028 $46 $89 $154 $263 $424 $976

2029 $38 $74 $128 $221 $361 $821

2030 $31 $61 $107 $185 $303 $686

2031 $25 $50 $88 $154 $253 $570

2032 $21 $41 $73 $127 $211 $473

2033 $17 $34 $60 $105 $175 $391

2034 $14 $29 $50 $87 $144 $324

2035 $12 $24 $42 $72 $119 $270

2036 $10 $21 $36 $61 $99 $227

2037 $9 $18 $31 $52 $84 $193

2038 $6 $15 $26 $45 $71 $164

2039 $6 $11 $23 $38 $62 $139

2040 $5 $10 $17 $33 $53 $118

2041 $4 $9 $15 $24 $46 $99

2042 $4 $8 $14 $22 $34 $81

2043 $4 $7 $12 $20 $30 $73

2044 $3 $6 $11 $18 $27 $66

2045 $3 $6 $10 $16 $25 $59

2046 $3 $5 $9 $14 $22 $53

2047 $2 $5 $8 $13 $20 $47

2048 $0 $4 $7 $11 $18 $40

2049 $0 $0 $6 $10 $16 $32

2050 $0 $0 $0 $9 $14 $23

NPV, 

3% $1,814 $2,786 $3,879 $5,420 $7,208 $21,108

NPV, 

7% $1,398 $2,063 $2,762 $3,715 $4,756 $14,693
Draft Regulatory Impact Analysis 

7-54 

Table 7-15: Upstream and Downstream CO2-Equivalent Benefits for the 3% SCC Value, Model Year Analysis 

(Millions of 2007 dollars) 

YEAR 2012 2013 2014 2015 2016 SUM 

2012 $278 $0 $0 $0 $0 $278

2013 $277 $439 $0 $0 $0 $717

2014 $277 $438 $629 $0 $0 $1,344

2015 $274 $437 $627 $905 $0 $2,243

2016 $270 $432 $626 $902 $1,240 $3,471

2017 $264 $426 $619 $901 $1,235 $3,445

2018 $257 $416 $610 $890 $1,234 $3,407

2019 $247 $404 $595 $878 $1,220 $3,344

2020 $236 $389 $578 $857 $1,202 $3,261

2021 $224 $371 $555 $831 $1,174 $3,154

2022 $210 $352 $529 $799 $1,138 $3,028

2023 $191 $329 $502 $761 $1,094 $2,878

2024 $166 $301 $469 $722 $1,042 $2,700

2025 $140 $261 $429 $676 $989 $2,494

2026 $117 $222 $373 $617 $925 $2,254

2027 $97 $186 $318 $537 $845 $1,982

2028 $80 $154 $267 $457 $736 $1,694

2029 $65 $128 $223 $384 $627 $1,427

2030 $53 $105 $186 $321 $527 $1,192

2031 $43 $87 $153 $267 $440 $990

2032 $36 $71 $127 $221 $367 $821

2033 $30 $59 $105 $182 $303 $679

2034 $25 $50 $87 $151 $250 $563

2035 $21 $42 $74 $125 $207 $469

2036 $18 $36 $62 $106 $173 $395

2037 $16 $31 $54 $90 $146 $336

2038 $11 $27 $46 $78 $124 $284

2039 $10 $19 $40 $66 $107 $242

2040 $9 $17 $29 $58 $91 $204

2041 $8 $15 $26 $42 $80 $172

2042 $7 $14 $24 $38 $59 $141

2043 $6 $12 $21 $34 $53 $127

2044 $6 $11 $19 $31 $47 $114

2045 $5 $10 $17 $27 $43 $102

2046 $4 $9 $15 $25 $38 $91

2047 $4 $8 $14 $22 $34 $82

2048 $0 $7 $12 $20 $31 $70

2049 $0 $0 $11 $18 $27 $56

2050 $0 $0 $0 $16 $24 $40

NPV, 

3% $3,151 $4,840 $6,738 $9,414 $12,519 $36,661

NPV, 

7% $2,428 $3,584 $4,796 $6,452 $8,260 $25,519
Environmental and Health Impacts 

7-55 

Table 7-16: Upstream and Downstream CO2-Equivalent Benefits for the 3% Newell-Pizer SCC Value, Model Year 

Analysis (Millions of 2007 dollars) 

YEAR 2012 2013 2014 2015 2016 SUM 

2012 $463 $0 $0 $0 $0 $463

2013 $462 $732 $0 $0 $0 $1,194

2014 $462 $730 $1,048 $0 $0 $2,240

2015 $457 $729 $1,044 $1,508 $0 $3,739

2016 $451 $721 $1,043 $1,503 $2,067 $5,784

2017 $441 $711 $1,031 $1,501 $2,059 $5,742

2018 $428 $694 $1,016 $1,484 $2,057 $5,679

2019 $412 $674 $992 $1,463 $2,033 $5,573

2020 $393 $648 $963 $1,428 $2,003 $5,435

2021 $373 $618 $925 $1,385 $1,956 $5,257

2022 $350 $586 $881 $1,332 $1,897 $5,046

2023 $319 $549 $836 $1,269 $1,824 $4,796

2024 $276 $501 $782 $1,204 $1,737 $4,500

2025 $233 $435 $715 $1,126 $1,648 $4,157

2026 $195 $369 $622 $1,029 $1,541 $3,756

2027 $161 $309 $530 $896 $1,408 $3,304

2028 $133 $257 $445 $762 $1,227 $2,824

2029 $109 $213 $371 $640 $1,044 $2,378

2030 $89 $176 $309 $534 $878 $1,986

2031 $72 $144 $256 $445 $733 $1,651

2032 $60 $119 $211 $368 $611 $1,368

2033 $50 $98 $174 $303 $506 $1,132

2034 $42 $83 $145 $251 $417 $938

2035 $36 $70 $123 $209 $345 $782

2036 $30 $60 $104 $177 $288 $658

2037 $26 $51 $90 $149 $243 $560

2038 $18 $44 $77 $129 $206 $474

2039 $16 $32 $67 $110 $178 $403

2040 $14 $29 $49 $96 $152 $340

2041 $13 $26 $44 $70 $133 $286

2042 $12 $23 $40 $63 $98 $236

2043 $10 $21 $36 $57 $88 $212

2044 $9 $18 $32 $51 $79 $190

2045 $8 $17 $29 $46 $71 $170

2046 $7 $15 $26 $41 $64 $152

2047 $7 $13 $23 $37 $57 $137

2048 $0 $12 $20 $33 $51 $116

2049 $0 $0 $18 $29 $46 $93

2050 $0 $0 $0 $26 $41 $67

NPV, 

3% $5,251 $8,066 $11,229 $15,690 $20,865 $61,102

NPV, 

7% $4,046 $5,973 $7,994 $10,753 $13,766 $42,531
Draft Regulatory Impact Analysis 

7-56 

7.6 Weight Reduction and Vehicle Safety 

 Over the past 20 years there has been a generally increasing trend in the weight of 

vehicles (see figure III.X-1 below from EPA’s Fuel Economy Trends Report). 289 There have 

been a number of factors contributing to this including: greater penetration of heavier trucks, 

introduction of SUVs, and an increasing amount of content in vehicles (including features for 

safety, noise reduction, added comfort, luxury, etc). This increased weight has been partially 

enabled by the increased efficiency of vehicles, especially in engines and transmissions. The 

impressive improvements in efficiency during this period have not only allowed for greater 

weight carrying capacity (and towing), but it has also allowed for greater acceleration 

performance in the fleet. Unfortunately, as the figure also shows, none of this efficiency 

improvement has been realized in fuel economy gains or GHG emissions reductions. 

 

Figure 7-6: Weight, 0-to-60 MPH acceleration time and adjusted fuel economy for light-duty vehicles

During this same period, the safety of vehicles has also undergone tremendous 

improvement. Vehicles are designed to better withstand both frontal and side impacts, 

occupants are protected better with increased seat belt usage and air bags, and drivers are able 

to avoid accidents with anti-lock brakes (ABS), electronic stability control (ESC), and 

improved tires and suspension. NHTSA anticipates a 12.6 percent reduction in fatality levels 

between 2007 and 2020 with safety improvements due to pending NHTSA FMVSS and other 

factors. Assuming that safety improvements will be made evenly throughout that period, EPA 

estimates the reduction in fatalities between 2007 and 2016 to be 8.7%. 

The interplay between vehicle weight and potential impact on safety is complex. 

While certainly an effective option for reducing CO2 emissions, the reduction of vehicle 

weight is a controversial and complicated topic. In a joint technical analysis, EPA and 

NHTSA agree that automakers could reduce weight as one part of the industries’ strategy for 
Environmental and Health Impacts 

7-57 

meeting the proposed standards. As shown in table III.D.6-3 of the Preamble, EPA is 

expecting that vehicle manufacturers will reduce the weight of their vehicles by 

approximately 4% on average between 2011 and 2016 although individual vehicles may have 

greater or smaller weight reduction (NHTSA’s results are similar using the Volpe model.) 

The penetration and magnitude of these changes are consistent with the public announcements 

made by many of the manufacturers since early 2008 and are consistent with the meetings that 

EPA has had with senior engineers and technical leadership at many of the automotive 

companies during 2008 and 2009. 

Between September 2008 and May 2009, EPA met with 11 major auto companies: 

GM, Chrysler, Ford, Nissan, Honda, Toyota, Mitsubishi, Hyundai/Kia, BMW, Mercedes and 

Volkswagen. Each company announced plans to reduce vehicle weight broadly across the 

passenger car vehicle and light truck categories within the 2012 to 2016 timeframe. Their 

plans for vehicle weight reduction are not limited to a single weight class but instead are 

expected to be implemented widely across the their products. The following statements 

summarize a number of automotive manufacturers’ future plans to reduce vehicle weight 

announced in the public domain within the past two year: 

 Ford: 250 to 750 pound weight reductions 2012 to 2020 across all vehicle platforms 

 Toyota: 30% weight reduction on 2015 Corolla and a 10% weight reduction on midsize vehicles by 2015 

 Nissan: 15% average weight reduction by 2015 

 Mazda: 100 kg (220 pound) weight reduction by 2011 and an additional 100 kg 

weight reduction by 2016 

 Mercedes: 5% average weight reduction by 2015 

Reducing vehicle mass without reducing the size, footprint or the structural integrity 

of the vehicle is technically feasible. Many of the technical options for doing so are outlined 

in Chapter 3 of the joint TSD and in this DRIA. Weight reduction can be accomplished by 

the proven methods described below. Every manufacturer can employ these methodologies to 

some degree, the magnitude to which each will be used will depend on opportunities within 

individual vehicle design. 

 Material Substitution: Substitution of lower density and/or higher strength materials 

in a manner that preserves or improves the function of the component. This includes 

substitution of high-strength steels, aluminum, magnesium or composite materials for 

components currently fabricated from mild steel, e.g., the magnesium-alloy front 

structure used on the 2009 Ford F150 pickups (we note that since these MY 2009 

F150s have only begun to enter the fleet, there is little real-world crash data available 

to evaluate the safety impacts of this new design). Light-weight materials with 

acceptable energy absorption properties can maintain structural integrity and 

absorption of crash energy relative to previous designs while providing a net decrease 

in component weight. 
Draft Regulatory Impact Analysis 

7-58 

 Smart Design: Computer aided engineering (CAE) tools can be used to better 

optimize load paths within structures by reducing stresses and bending moments 

without adversely affecting structural integrity. This allows better optimization of the 

sectional thicknesses of structural components to reduce mass while maintaining or 

improving the function of the component. Smart designs also integrate separate parts 

in a manner that reduces mass by combining functions or the reduced use of separate 

fasteners. In addition, some “body on frame” vehicles are redesigned with a lighter 

“unibody” construction with little compromise in vehicle functionality. 

 Reduced Powertrain Requirements: Reducing vehicle weight sufficiently allows for 

the use of a smaller, lighter and more efficient engine while maintaining or increasing 

performance. Approximately half of the reduction is due to these reduced powertrain 

output requirements from reduced engine power output and/or displacement, lighter 

weight transmission and final drive gear ratios. The subsequent reduced rotating mass 

(e.g. transmission, driveshafts/halfshafts, wheels and tires) via weight and/or size 

reduction of components are made possible by reduced torque output requirements. 

 Mass Decompounding: Following from the point above, the compounded weight 

reductions of the body, engine and drivetrain can reduce stresses on the suspension 

components, steering components, brakes, and thus allow further reductions in the 

weight of these subsystems. The reductions in weight for unsprung masses such as 

brakes, control arms, wheels and tires can further reduce stresses in the suspension 

mounting points which can allow still further reductions in weight. For example, 

lightweighting can allow for the reduction in the size of the vehicle brake system, 

while maintaining the same stopping distance. It is estimated that 1.25 kilograms of 

secondary weight savings can be achieved for every kilogram of weight saved on a 

vehicle when all subsystems are redesigned to take into account the initial primary 

weight savings.290 

Weight reduction is broadly applicable across all vehicle subsystems including the 

engine, exhaust system, transmission, chassis, suspension, brakes, body, closure panels, 

glazing, seats and other interior components, engine cooling systems and HVAC systems. 

EPA believes it is both technically feasible to reduce weight without reducing vehicle size, 

footprint or structural strength and manufacturers have indicated to the agencies that they will 

use these approaches to accomplish these tasks. We request written comment on this 

assessment and this projection, including up-to-date plans regarding the extent of use by each 

manufacturer of each of the methodologies described above. 

EPA also projects that automakers will not reduce footprint in order to meet the 

proposed CO2 standards in our modeling analysis. NHTSA and EPA have taken two 

measures to help ensure that the proposed rules provide no incentive for mass reduction to be 

accompanied by a corresponding decrease in the footprint of the vehicle (with its concomitant 

decrease in crush and crumple zones). The first design feature of the proposed rule is that the 

CO2 or fuel economy targets are based on the attribute of footprint (which is a surrogate for 
Environmental and Health Impacts 

7-59 

vehicle size).R

 The second design feature is that the shape of the footprint curve (or function) 

has been carefully chosen such that it neither encourages manufacturers to increase, nor 

decrease the footprint of their fleet. Thus, the standard curves are designed to be 

approximately “footprint neutral” within the sloped portion of the function.S

 For further 

discussion on this, refer to Section II.C of the preamble, or Chapter 2 of the joint TSD. Thus 

the agencies are assuming in their modeling analysis that the manufacturers could reduce 

vehicle mass without reducing vehicle footprint as one way to respond to the proposed rule.T

 

In Section IV of the preamble, NHTSA presents a safety analysis of the proposed 

CAFE standards based on the 2003 Kahane analysis. NHTSA’s Dr. Charles Kahane 

performed a thorough review on historical data regarding the relationship between mass 

reduction, wheel base, track width and fatality risk.291,292 The results from 1991-1999 vehicle 

data indicate that a heavier vehicle is safer than a lighter one based on the assumption that 

historical vehicle mass reductions are accompanied with vehicle size and footprint reductions. 

As discussed in Section IV of the Preamble, NHTSA has developed a worse case 

estimate of the impact of weight reductions on fatalities. The underlying data used for that 

analysis does not allow NHTSA to analyze the specific impact of weight reduction at constant 

footprint because historically there have not been a large number of vehicles produced that 

relied substantially on material substitution. Rather, the data set includes vehicles that were 

either smaller and lighter or larger and heavier. The numbers in the NHTSA analysis predict 

the safety-related fatality consequences that would occur in the unlikely event that weight 

reduction for model years 2012-2016 is accomplished by reducing mass and reducing 

footprint. EPA concurs with NHTSA that the safety analysis conducted by NHTSA and 

presented in Section IV is a worst case analysis for fatalities and we expect the actual impacts 

on vehicle safety could be much less. EPA and NHTSA are not able to quantify the lowerbound or the best-case potential impacts at this time. 

The 2005 Dynamic Research, Incorporated (DRI) studies assessed the independent 

effects of vehicle weight and size on safety in order to determine if there are tradeoffs 

between improving vehicle safety and fuel consumption. In their 2005 studies,293,294 one of 

which was published as a Society of Automotive Engineers Technical Paper and received peer 

review through that body, DRI presented results that indicate that vehicle weight reduction 

tends to decrease fatalities, but vehicle wheelbase and track reduction tends to increase 

fatalities. The DRI work focused on four major points, with #1 and #4 being discussed with 

additional detail below: 

 R

 As the footprint attribute is defined as wheelbase times track width, the footprint target curves do not 

discourage manufacturers from reducing vehicle size by reducing front, rear, or side overhang, which can impact 

safety by resulting in less crush space. 

S

 This neutrality with respect to footprint does not extend to the smallest and largest vehicles, because the 

function is limited, or flattened, in these footprint ranges 

T

 See Chapter 1 of the joint TSD for a description of potential footprint changes in the 2016 reference fleet 
Draft Regulatory Impact Analysis 

7-60 

1. 2-Door vehicles represented a significant portion of the light duty fleet 

and should not be ignored. 

2. Directional control and therefore crash avoidance improves with a 

reduction in curb weight. 

3. The occupants of the impacted vehicle, or “collision partner” benefit 

from being impacted by a lighter vehicle. 

4. Rollover fatalities are reduced by a reduction in curb weight due to 

lower centers of gravity and lower loads on the roof structures. 

The data used for the DRI analysis was similar to NHTSA’s 2003 Kahane study, using 

Fatality Analysis Reporting System (FARS) data for vehicle model years 1985 through 1998 

for cars, and 1985 through 1997 trucks. This data overlaps Kahane’s FARS data on model 

year 1991 to 1999 vehicles. DRI also used a logistical regression method similar to the 

approach taken by the 2003 Kahane study. However, DRI included 2-door passenger cars, 

whereas the Kahane study excluded all 2-door vehicles. The 2003 Kahane study excluded 2-

door passenger cars because it found that for MY 1991-1999 vehicles, sports and muscle cars 

constituted a significant proportion of those vehicles. These vehicles have relatively high 

weight relative to their wheelbase, and are also disproportionately involved in crashes. Thus, 

Kahane concluded that including these vehicles in the analysis excessively skewed the 

regression results. As of July 1, 1999, 2-door passenger cars represented 29% of the 

registered cars in the United States. The majority of 2-door vehicles excluded in the 2003 

Kahane study and included in DRI's analysis were high-sales volume light-duty vehicles and 

vehicles shared common vehicle platforms and architectures with 4-door vehicles that were 

included in the 2003 Kahane study. Specific examples include the Chevrolet Cavalier and 

Monte Carlo, Oldsmobile Achieva and Supreme, Buick Riviera, Ford Escort and Probe, 

Mercury Tracer, Honda Civic, Hyundai Accent, and VW Golf which do not necessarily 

represent high-weight, short-wheelbase sports and high-performance vehicle types. DRI’s 

position was that this is a significant portion of the light duty fleet, too large to be ignored, 

and conclusions regarding the effects of weight and safety should be based on data for all 

cars, not just 4-doors. 

DRI did, however, state in their conclusions that the results are sensitive to removing 

data for 2-doors and wagons, and that the results for 4-door cars with respect to the effects of 

wheelbase and track width were no longer statistically significant when 2-door cars were 

removed. EPA and NHTSA recognize the technical challenges of properly accounting for 2-

door cars in a regression analysis evaluating the impacts of vehicle weight on safety, due to 

the concerns discussed for the Kahane study above. Thus, the agencies seek comment on how 

to ensure that any analysis supporting the final rule accounts as fully as possible for the range 

of safety impacts due to weight reduction on the variety of vehicles regulated under these 

proposed standards. 

The DRI and Kahane studies also differ with respect to the impact of vehicle weight 

on rollover fatalities. The Kahane study treated curb weight as a surrogate for size and weight 

and analyzed them as a single variable. Using this method, the 2003 Kahane analysis 
Environmental and Health Impacts 

7-61 

indicates that curb weight reductions would increase fatalities due to rollovers. The DRI 

study differed by analyzing curb weight, wheelbase, and track as multiple variables and 

concluded that curb weight reduction would decrease rollover fatalities, and wheelbase and 

track reduction would increase rollover fatalities. DRI offers two potential root causes for 

higher curb weight resulting in higher rollover fatalities. The first is that a taller vehicle tends 

to be heavier than a shorter vehicle; therefore heavier vehicles may be more likely to rollover 

because the vehicle height and weight are correlated with vehicle center of gravity height. 

The second is that FMVSS 216 for roof crush strength requirements for passenger cars of 

model years 1995 through 1999 were proportional to the unloaded vehicle weight if the 

weight is less than 3,333 lbs, however they were a constant if the weight is greater than 3,333 

lbs. Therefore heavier vehicles may have had relatively less rollover crashworthiness. 

NHTSA has rejected the DRI analysis, and has not relied on it for its evaluation of 

safety impact changes in CAFE standards. See Section IV.G.6 of this Notice, as well as 

NHTSAs March 2009 Final Rulemaking for MY2011 CAFE standards (see 74 FR at 14402-

05). 

The DRI and Kahane analysis of the FARS data appear to be quite similar in one 

respect because the results are reproducible between the two studies when using aggregated 

vehicle attributes for 4-door cars.293,294,295 The two analyses differ when individual vehicle 

attributes of mass, wheelbase and track width are separately analyzed. NHTSA has raised this 

as a concern with the DRI study. When 2-door vehicles are removed from the data set EPA 

is concerned that the results may no longer be statistically significant with respect to 

independent vehicle attributes due to the small size of the remaining data set, as DRI stated in 

the 2005 study. 

The DRI analysis concluded that there would be small additional reductions in 

fatalities for cars and trucks if the weight reduction occurs without accompanying vehicle 

footprint or size changes. EPA notes that if DRI’s results were to be applied using the curb 

weight reductions predicted by the OMEGA model, an overall reduction in fatalities would be 

predicted. EPA invites comment on all aspects of the issue of the impact of this kind of 

weight reduction on safety, including the usefulness of the DRI study in evaluating this issue. 

The agencies are committed to continuing to analyze vehicle safety issues so a more 

informed evaluation can be made. We request comment on this issue. These comments 

should include not only further discussion and analysis of the relevant studies but data and 

analysis which can allow the agencies to more accurately quantify any potential safety issues 

with the proposed standards.
Draft Regulatory Impact Analysis 

7-62 

References 

References can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472 or are 

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5

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6

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7

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8

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77 U.S. EPA (2009) National-Scale Air Toxics Assessment for 2002. http://www.epa.gov/ttn/atw/nata2002. 
Environmental and Health Impacts 

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 78 U.S. EPA. 2000. Integrated Risk Information System File for Benzene. This material is available 

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79 International Agency for Research on Cancer, IARC monographs on the evaluation of carcinogenic risk of 

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81 International Agency for Research on Cancer (IARC). 1987. Monographs on the evaluation of carcinogenic 

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82 U.S. Department of Health and Human Services National Toxicology Program 11th Report on Carcinogens 

available at: http://ntp.niehs.nih.gov/go/16183. 

83 Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82: 193-197. 

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Chinese workers heavily exposed to benzene. Am. J. Ind. Med. 29: 236-246.

86 U.S. EPA 2002 Toxicological Review of Benzene (Noncancer Effects). Environmental Protection Agency, 

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Assessment, Washington DC. This material is available electronically at http://www.epa.gov/iris/subst/0276.htm.

87 Qu, O.; Shore, R.; Li, G.; Jin, X.; Chen, C.L.; Cohen, B.; Melikian, A.; Eastmond, D.; Rappaport, S.; Li, H.; 

Rupa, D.; Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kwok, E.; Li, Y.; Mu, R.; Xu, 

B.; Zhang, X.; Li, K. (2003). HEI Report 115, Validation & Evaluation of Biomarkers in Workers Exposed to 

Benzene in China. 

88 Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et al. (2002). Hematological changes among Chinese 

workers with a broad range of benzene exposures. Am. J. Industr. Med. 42: 275-285.

89 Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004). Hematotoxically in Workers Exposed to Low 

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90 Turtletaub, K.W. and Mani, C. (2003). Benzene metabolism in rodents at doses relevant to human exposure 

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218 Byun, D.W., and Schere, K.L., 2006. Review of the Governing Equations, Computational Algorithms, and 

Other Components of the Models-3 Community Multiscale Air Quality (CMAQ) Modeling System, J. Applied 

Mechanics Reviews, 59 (2), 51-77.

219 Dennis, R.L., Byun, D.W., Novak, J.H., Galluppi, K.J., Coats, C.J., and Vouk, M.A., 1996. The next 

generation of integrated air quality modeling: EPA’s Models-3, Atmospheric Environment, 30, 1925-1938. 220 US EPA (2007). Regulatory Impact Analysis of the Proposed Revisions to the National Ambient Air Quality 

Standards for Ground-Level Ozone. EPA document number 442/R-07-008, July 2007. 

221 Aiyyer, A, Cohan, D., Russell, A., Stockwell, W., Tanrikulu, S., Vizuete, W., Wilczak, J., 2007. Final Report: 

Third Peer Review of the CMAQ Model. p. 23.

222 Grell, G., Dudhia, J., Stauffer, D. (1994). A Description of the Fifth-Generation Penn State/NCAR Mesoscale 

Model (MM5), NCAR/TN-398+STR., 138 pp, National Center for Atmospheric Research, Boulder CO. 

223 Grell, G., Dudhia, J., Stauffer, D. (1994). A Description of the Fifth-Generation Penn State/NCAR Mesoscale 

Model (MM5), NCAR/TN-398+STR., 138 pp, National Center for Atmospheric Research, Boulder CO.

224 Yantosca, B. (2004). GEOS-CHEMv7-01-02 User’s Guide, Atmospheric Chemistry Modeling Group, 

Harvard University, Cambridge, MA, October 15, 2004. 

225 U.S. Environmental Protection Agency. (2008). Final Ozone NAAQS Regulatory Impact Analysis. 

Prepared by: Office of Air and Radiation, Office of Air Quality Planning and Standards. March. 

226 U.S. Environmental Protection Agency. October 2006. Final Regulatory Impact Analysis (RIA) for the 

Proposed National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation. 

227 U.S. Environmental Protection Agency (U.S. EPA). 2009a. Regulatory Impact Analysis: National Emission 

Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry. Office of Air 

Quality Planning and Standards, Research Triangle Park, NC. April. Available on the Internet at 

<http://www.epa.gov/ttn/ecas/regdata/RIAs/portlandcementria_4-20-09.pdf>. 

228 U.S. Environmental Protection Agency (U.S. EPA). 2009b. Proposed NO2 NAAQS Regulatory Impact 

Analysis (RIA). Office of Air Quality Planning and Standards, Research Triangle Park, NC. April. Available 

on the Internet at http://www.epa.gov/ttn/ecas/regdata/RIAs/proposedno2ria.pdf. 

229 U.S. Environmental Protection Agency (U.S. EPA). 2008a. Regulatory Impact Analysis, 2008 National 

Ambient Air Quality Standards for Ground-level Ozone, Chapter 6. Office of Air Quality Planning and 

Standards, Research Triangle Park, NC. March. Available at <http://www.epa.gov/ttn/ecas/regdata/RIAs/6-

ozoneriachapter6.pdf>. 

230 U.S. Environmental Protection Agency (U.S. EPA). 2009a. Regulatory Impact Analysis: National Emission 

Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry. Office of Air 

Quality Planning and Standards, Research Triangle Park, NC. April. Available on the Internet at 

<http://www.epa.gov/ttn/ecas/regdata/RIAs/portlandcementria_4-20-09.pdf>. 

231 U.S. Environmental Protection Agency (U.S. EPA). 2009b. Proposed NO2 NAAQS Regulatory Impact 

Analysis (RIA). Office of Air Quality Planning and Standards, Research Triangle Park, NC. April. Available 

on the Internet at http://www.epa.gov/ttn/ecas/regdata/RIAs/proposedno2ria.pdf. 
Draft Regulatory Impact Analysis 

7-76 

 232 U.S. Environmental Protection Agency (U.S. EPA). 2008b. Technical Support Document: Calculating 

Benefit Per-Ton estimates, Ozone NAAQS Docket #EPA-HQ-OAR-2007-0225-0284. Office of Air Quality 

Planning and Standards, Research Triangle Park, NC. March. Available on the Internet at 

<http://www.regulations.gov>. 

233 Fann, N. et al. (2009). The influence of location, source, and emission type in estimates of the human health 

benefits of reducing a ton of air pollution. Air Qual Atmos Health. Published online: 09 June, 2009. 

234 Pope, C.A., III, R.T. Burnett, M.J. Thun, E.E. Calle, D. Krewski, K. Ito, and G.D. Thurston. 2002. “Lung 

Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution.” Journal of the 

American Medical Association 287:1132-1141. 

235 Laden, F., J. Schwartz, F.E. Speizer, and D.W. Dockery. 2006. “Reduction in Fine Particulate Air Pollution 

and Mortality.” American Journal of Respiratory and Critical Care Medicine 173:667-672. Estimating the 

Public Health Benefits of Proposed Air Pollution Regulations. Washington, DC: The National Academies Press. 

236 Roman, Henry A., Katherine D. Walker, Tyra L. Walsh, Lisa Conner, Harvey M. Richmond, Bryan J. 

Hubbell, and Patrick L. Kinney. 2008. Expert Judgment Assessment of the Mortality Impact of Changes in 

Ambient Fine Particulate Matter in the U.S. Environ. Sci. Technol., 42(7):2268-2274. 

237 Industrial Economics, Inc. 2006. Expanded Expert Judgment Assessment of the Concentration-Response 

Relationship Between PM2.5 Exposure and Mortality. Prepared for the U.S. EPA, Office of Air Quality 

Planning and Standards, September. Available on the Internet at 

<http://www.epa.gov/ttn/ecas/regdata/Uncertainty/pm_ee_report.pdf> 

238 Mrozek, J.R., and L.O. Taylor. 2002. “What Determines the Value of Life? A Meta-Analysis.” Journal of 

Policy Analysis and Management 21(2):253-270. 

239 Viscusi, V.K., and J.E. Aldy. 2003. “The Value of a Statistical Life: A Critical Review of Market Estimates 

throughout the World.” Journal of Risk and Uncertainty 27(1):5-76. 

240 Kochi, I., B. Hubbell, and R. Kramer. 2006. An Empirical Bayes Approach to Combining Estimates of the 

Value of Statistical Life for Environmental Policy Analysis. Environmental and Resource Economics. 34: 385-

406. 

241 U.S. Environmental Protection Agency (U.S. EPA). 2000. Guidelines for Preparing Economic Analyses. 

EPA 240-R-00-003. National Center for Environmental Economics, Office of Policy Economics and 

Innovation. Washington, DC. September. Available on the Internet at 

<http://yosemite.epa.gov/ee/epa/eed.nsf/webpages/Guidelines.html/$file/cover.pdf>. 

242 Information on BenMAP, including downloads of the software, can be found at http://www.epa.gov/ttn/ecas/ 

benmodels.html. 

243 Bell, M.L., et al. (2004). Ozone and short-term mortality in 95 US urban communities, 1987-2000. JAMA, 

2004. 292(19): p. 2372-8. 

244 Huang, Y.; Dominici, F.; Bell, M. L. (2005) Bayesian hierarchical distributed lag models for summer ozone 

exposure and cardio-respiratory mortality. Environmetrics. 16: 547-562. 

245 Schwartz, J. (2005) How sensitive is the association between ozone and daily deaths to control for 

temperature? Am. J. Respir. Crit. Care Med. 171: 627-631. 

246 Bell, M.L., F. Dominici, and J.M. Samet. (2005). A meta-analysis of time-series studies of ozone and 

mortality with comparison to the national morbidity, mortality, and air pollution study. Epidemiology. 16(4): p. 

436-45. 
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 247 Ito, K., S.F. De Leon, and M. Lippmann (2005). Associations between ozone and daily mortality: analysis 

and meta-analysis. Epidemiology. 16(4): p. 446-57. 

248 Levy, J.I., S.M. Chemerynski, and J.A. Sarnat. (2005). Ozone exposure and mortality: an empiric bayes 

metaregression analysis. Epidemiology. 16(4): p. 458-68. 

249 Pope, C.A., III, R.T. Burnett, M.J. Thun, E.E. Calle, D. Krewski, K. Ito, and G.D. Thurston. (2002). “Lung 

Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution.” Journal of the 

American Medical Association 287:1132-1141. 

250 Laden, F., J. Schwartz, F.E. Speizer, and D.W. Dockery. (2006). Reduction in Fine Particulate Air 

Pollution and Mortality. American Journal of Respiratory and Critical Care Medicine. 173: 667-672. 

251 Industrial Economics, Incorporated (IEc). (2006). Expanded Expert Judgment Assessment of the 

Concentration-Response Relationship Between PM2.5 Exposure and Mortality. Peer Review Draft. Prepared 

for: Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle 

Park, NC. August. 

252 Woodruff, T.J., J. Grillo, and K.C. Schoendorf. (1997). The Relationship Between Selected Causes of 

Postneonatal Infant Mortality and Particulate Air Pollution in the United States. Environmental Health 

Perspectives. 105(6):608-612. 

253 Abbey, D.E., B.L. Hwang, R.J. Burchette, T. Vancuren, and P.K. Mills. (1995). Estimated Long-Term 

Ambient Concentrations of PM(10) and Development of Respiratory Symptoms in a Nonsmoking Population. 

Archives of Environmental Health. 50(2): 139-152. 

254 Peters, A., D.W. Dockery, J.E. Muller, and M.A. Mittleman. (2001). Increased Particulate Air Pollution and 

the Triggering of Myocardial Infarction. Circulation. 103:2810-2815. 

255 Schwartz J. (1995). Short term fluctuations in air pollution and hospital admissions of the elderly for 

respiratory disease. Thorax. 50(5):531-538. 

256 Schwartz J. (1994a). PM(10) Ozone, and Hospital Admissions For the Elderly in Minneapolis St Paul, 

Minnesota. Arch Environ Health. 49(5):366-374. 

257 Schwartz J. (1994b). Air Pollution and Hospital Admissions For the Elderly in Detroit, Michigan. Am J 

Respir Crit Care Med. 150(3):648-655. 

258 Moolgavkar SH, Luebeck EG, Anderson EL. (1997). Air pollution and hospital admissions for respiratory 

causes in Minneapolis St. Paul and Birmingham. Epidemiology. 8(4):364-370. 

259 Burnett RT, Smith-Doiron M, Stieb D, Raizenne ME, Brook JR, Dales RE, et al. (2001). Association 

between ozone and hospitalization for acute respiratory diseases in children less than 2 years of age. Am J 

Epidemiol. 153(5):444-452. 

260 Moolgavkar, S.H. (2003). “Air Pollution and Daily Deaths and Hospital Admissions in Los Angeles and 

Cook Counties.” In Revised Analyses of Time-Series Studies of Air Pollution and Health. Special Report. 

Boston, MA: Health Effects Institute. 

261 Ito, K. (2003). “Associations of Particulate Matter Components with Daily Mortality and Morbidity in 

Detroit, Michigan.” In Revised Analyses of Time-Series Studies of Air Pollution and Health. Special Report. 

Health Effects Institute, Boston, MA. 

262 Moolgavkar, S.H. (2000). Air Pollution and Hospital Admissions for Diseases of the Circulatory System in 

Three U.S. Metropolitan Areas. Journal of the Air and Waste Management Association 50:1199-1206. 

263 Sheppard, L. (2003). Ambient Air Pollution and Nonelderly Asthma Hospital Admissions in Seattle, 

Washington, 1987-1994. In Revised Analyses of Time-Series Studies of Air Pollution and Health. Special 

Report. Boston, MA: Health Effects Institute. 

264 Jaffe DH, Singer ME, Rimm AA. (2003). Air pollution and emergency department visits for asthma among 

Ohio Medicaid recipients, 1991-1996. Environ Res 91(1):21-28. 
Draft Regulatory Impact Analysis 

7-78 

 265 Peel, J. L., P. E. Tolbert, M. Klein, et al. (2005). Ambient air pollution and respiratory emergency department 

visits. Epidemiology. Vol. 16 (2): 164-74. 

266 Wilson, A. M., C. P. Wake, T. Kelly, et al. (2005). Air pollution, weather, and respiratory emergency room 

visits in two northern New England cities: an ecological time-series study. Environ Res. Vol. 97 (3): 312-21. 

267 Norris, G., S.N. YoungPong, J.Q. Koenig, T.V. Larson, L. Sheppard, and J.W. Stout. (1999). An 

Association between Fine Particles and Asthma Emergency Department Visits for Children in Seattle. 

Environmental Health Perspectives 107(6):489-493. 

268 Dockery, D.W., J. Cunningham, A.I. Damokosh, L.M. Neas, J.D. Spengler, P. Koutrakis, J.H. Ware, M. 

Raizenne, and F.E. Speizer. (1996). Health Effects of Acid Aerosols On North American Children-Respiratory 

Symptoms. Environmental Health Perspectives 104(5):500-505. 

269 Pope, C.A., III, D.W. Dockery, J.D. Spengler, and M.E. Raizenne. (1991). Respiratory Health and PM10

Pollution: A Daily Time Series Analysis. American Review of Respiratory Diseases 144:668-674. 

270 Schwartz, J., and L.M. Neas. (2000). Fine Particles are More Strongly Associated than Coarse Particles with 

Acute Respiratory Health Effects in Schoolchildren. Epidemiology 11:6-10. 

271 Ostro, B., M. Lipsett, J. Mann, H. Braxton-Owens, and M. White. (2001). Air Pollution and Exacerbation of 

Asthma in African-American Children in Los Angeles. Epidemiology 12(2):200-208. 

272 Vedal, S., J. Petkau, R. White, and J. Blair. (1998). Acute Effects of Ambient Inhalable Particles in 

Asthmatic and Nonasthmatic Children. American Journal of Respiratory and Critical Care Medicine

157(4):1034-1043. 

273 Ostro, B.D. (1987). Air Pollution and Morbidity Revisited: A Specification Test. Journal of Environmental 

Economics Management 14:87-98. 

274 Gilliland FD, Berhane K, Rappaport EB, Thomas DC, Avol E, Gauderman WJ, et al. (2001). The effects of 

ambient air pollution on school absenteeism due to respiratory illnesses. Epidemiology 12(1):43-54. 

275 Chen L, Jennison BL, Yang W, Omaye ST. (2000). Elementary school absenteeism and air pollution. Inhal 

Toxicol 12(11):997-1016. 

276 Ostro, B.D. and S. Rothschild. (1989). Air Pollution and Acute Respiratory Morbidity: An Observational 

Study of Multiple Pollutants. Environmental Research 50:238-247. 

277 Russell, M.W., D.M. Huse, S. Drowns, E.C. Hamel, and S.C. Hartz. (1998). Direct Medical Costs of 

Coronary Artery Disease in the United States. American Journal of Cardiology 81(9):1110-1115. 

278 Wittels, E.H., J.W. Hay, and A.M. Gotto, Jr. (1990). Medical Costs of Coronary Artery Disease in the 

United States. American Journal of Cardiology 65(7):432-440. 

279 Smith, D.H., D.C. Malone, K.A. Lawson, L.J. Okamoto, C. Battista, and W.B. Saunders. (1997). A National 

Estimate of the Economic Costs of Asthma. American Journal of Respiratory and Critical Care Medicine 156(3 

Pt 1):787-793. 

280 Stanford, R., T. McLaughlin, and L.J. Okamoto. (1999). The Cost of Asthma in the Emergency Department 

and Hospital. American Journal of Respiratory and Critical Care Medicine 160(1):211-215. 

281 Rowe, R.D., and L.G. Chestnut. (1986). Oxidants and Asthmatics in Los Angeles: A Benefits Analysis—

Executive Summary. Prepared by Energy and Resource Consultants, Inc. Report to the U.S. Environmental 

Protection Agency, Office of Policy Analysis. EPA-230-09-86-018. Washington, DC. 

282 Science Advisory Board. 2001. NATA – Evaluating the National-Scale Air Toxics Assessment for 1996 – 

an SAB Advisory. http://www.epa.gov/ttn/atw/sab/sabrev.html. 

283 MiniCAM is a long-term, global integrated assessment model of energy, economy, agriculture and land use, 

that considers the sources of emissions of a suite of greenhouse gases (GHG's), emitted in 14 globally 

disaggregated regions, the fate of emissions to the atmosphere, and the consequences of changing concentrations 
Environmental and Health Impacts 

7-79 

 of greenhouse related gases for climate change. MiniCAM begins with a representation of demographic and 

economic developments in each region and combines these with assumptions about technology development to 

describe an internally consistent representation of energy, agriculture, land-use, and economic developments that 

in turn shape global emissions. 

Brenkert A, S. Smith, S. Kim, and H. Pitcher, 2003: Model Documentation for the MiniCAM. PNNL-14337, 

Pacific Northwest National Laboratory, Richland, Washington. 

284 MAGICC consists of a suite of coupled gas-cycle, climate and ice-melt models integrated into a single 

framework. The framework allows the user to determine changes in greenhouse-gas concentrations, global-mean 

surface air temperature and sea-level resulting from anthropogenic emissions of carbon dioxide (CO2), methane 

(CH4), nitrous oxide (N2O), reactive gases (CO, NOx, VOCs), the halocarbons (e.g. HCFCs, HFCs, PFCs) and 

sulfur dioxide (SO2). MAGICC emulates the global-mean temperature responses of more sophisticated coupled 

Atmosphere/Ocean General Circulation Models (AOGCMs) with high accuracy. 

Wigley, T.M.L. and Raper, S.C.B. 1992. Implications for Climate And Sea-Level of Revised IPCC Emissions 

Scenarios Nature 357, 293-300. Raper, S.C.B., Wigley T.M.L. and Warrick R.A. 1996. in Sea-Level Rise 

and Coastal Subsidence: Causes, Consequences and Strategies J.D. Milliman, B.U. Haq, Eds., Kluwer 

Academic Publishers, Dordrecht, The Netherlands, pp. 11-45. 

Wigley, T.M.L. and Raper, S.C.B. 2002. Reasons for larger warming projections in the IPCC Third Assessment 

Report J. Climate 15, 2945-2952. 

285This scenario is used because it contains a comprehensive suite of greenhouse and pollutant gas emissions. 

The four RCP scenarios will be used as common inputs into a variety of Earth System Models for inter-model 

comparisons leading to the IPCC AR5 (Moss et al. 2008). The MiniCAM RCP4.5 is based on the scenarios 

presented in Clarke et al. (2007) with non-CO2 and pollutant gas emissions implemented as described in Smith 

and Wigley (2006). Base-year information has been updated to the latest available data for the RCP process. The 

final RCP4.5 scenario will be available at the IAMC scenario Web site (www.iiasa.ac.at/web-apps/tnt/RcpDb/). 

Clarke, L., J. Edmonds, H. Jacoby, H. Pitcher, J. Reilly, R. Richels, (2007) Scenarios of Greenhouse Gas 

Emissions and Atmospheric Concentrations. Sub-report 2.1A of Synthesis and Assessment Product 2.1 by 

the U.S. Climate Change Science Program and the Subcommittee on Global Change Research (Department 

of Energy, Office of Biological & Environmental Research, Washington, DC., USA, 154 pp.). 

Moss, Richard, Mustafa Babiker, Sander Brinkman, Eduardo Calvo, Tim Carter, Jae Edmonds, Ismail Elgizouli, 

Seita Emori, Lin Erda, Kathy Hibbard, Roger Jones, Mikiko Kainuma, Jessica Kelleher, Jean Francois 

Lamarque, Martin Manning, Ben Matthews, Jerry Meehl, Leo Meyer, John Mitchell, Nebojsa Nakicenovic, 

Brian O’Neill, Ramon Pichs, Keywan Riahi, Steven Rose, Paul Runci, Ron Stouffer, Detlef van Vuuren, 

John Weyant, Tom Wilbanks, Jean Pascal van Ypersele, and Monika Zurek (2008) Towards New Scenarios 

for Analysis of Emissions, Climate Change, Impacts, and Response Strategies (Intergovernmental Panel on 

Climate Change, Geneva) 132 pp. 

Smith, Steven J. and T.M.L. Wigley (2006) "Multi-Gas Forcing Stabilization with the MiniCAM" Energy 

Journal (Special Issue #3). 

286 In IPCC reports, equilibrium climate sensitivity refers to the equilibrium change in the annual mean global 

surface temperature following a doubling of the atmospheric equivalent carbon dioxide concentration. The IPCC 

states that climate sensitivity is “likely” to be in the range of 2°C to 4.5°C, “very unlikely” to be less than 1.5°C, 

and “values substantially higher than 4.5°C cannot be excluded.” IPCC WGI, 2007, Climate Change 2007 - The 

Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the IPCC, 

http://www.ipcc.ch/. 

287 IPCC WGI, 2007. The baseline temperature increases by 2100 from our MiniCAM-MAGICC runs are 1.8°C 

to 4.5°C. 
Draft Regulatory Impact Analysis 

7-80 

 288 IPCC WGII. 2007. Climate Change 2007 - Impacts, Adaptation and Vulnerability Contribution of Working 

Group II to the Fourth Assessment Report of the IPCC. 

289 “Light-Duty Automotive Technology and Fuel Economy Trends: 1975 Through 2008”, EPA420-R-08-015, 

U.S. Environmental Protection Agency Office of Transportation and Air Quality, September 2008 

290 “Future Generation Passenger Compartment-Validation” in “Lightweighting Materials – FY 2008 Progress 

Report”, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies 

Program, May 2009. 

291 “Relationship between Vehicle Size and Fatality Risk in Model Year 1985-93 Passenger cars and Light 

Trucks”, DOT HS 808 570, NHTSA Technical Report, January 1997 

292 “Vehicle Weight, Fatality Risk and Crash Compatibility of Model Year 1991-99 Passenger Cars and Light 

Trucks”, DOT HS 809 663, NHTSA Technical Report, October 2003 

293 “Supplemental Results on the Independent Effects of Curb Weight, Wheelbase and Track on Fatality Risk”, 

Dynamic Research, Inc., DRI-TR-05-01, May 2005 

294 “An Assessment of the Effects of Vehicle Weight and Size on Fatality Risk in 1985 to 1998 Model Year 

Passenger Cars and 1985 to 1997 Model Year Light Trucks and Vans”, Van Auken, M., Zellner J.W., SAE 

Technical Paper Number 2005-01-1354, 2005. 

295 FR Vol. 74, No. 59, beginning on pg. 14402 
Other Economic and Social Impacts 

8-1 

CHAPTER 8:Other Economic and Social Impacts 

8.1 Vehicle Sales Impacts 

8.1.1 How Vehicle Sales Impacts were Estimated for this Rule 

The vehicle sales impacts discussed in Section III.H.4 of the preamble to the proposal 

and presented below in Table 8-1 and Table 8-2 were derived using the following 

methodology. For additional discussion of the assumptions used in the vehicles sales impacts, 

see Section III.H of the preamble. The calculation is performed for an average car and an 

average truck, rather than for individual vehicles. The analysis conducted for this rule does 

not have the precision to examine effects on individual manufacturers or different vehicle 

classes. Chapter 8.1.2 provides our assessment of models that examine these questions. 

The analysis starts with the increase in costs estimated by OMEGA. We assume that 

these costs are fully passed along to consumers. This assumption is appropriate for cost 

increases in perfectly competitive markets. In less than perfectly competitive markets, 

though, it is likely that the cost increase is split between consumers and automakers, and the 

price is not likely to increase as much as costs.1

 Thus, the assumption of full cost passthrough is probably an overestimate, and price is not likely to increase as much as estimated 

here. 

The next step in the analysis is to adjust this cost increase for other effects on the 

consumer. We assume that the consumer holds onto this vehicle for 5 years and then sells it. 

The higher vehicle price is likely to lead to an increase in sales tax, insurance, and vehicle 

financing costs, as well as increases in the resale value of the vehicle. These factors weigh 

against each other: the higher sales tax and insurance costs increase costs to consumers; the 

higher resale value allows consumers to recover a portion of these costs. 

The increase in insurance costs is estimated from the average value of collision plus 

comprehensive insurance as a proportion of average new vehicle price. Collision plus 

comprehensive insurance is the portion of insurance costs that depend on vehicle value. The 

Insurance Information Institute2

 provides the average value of collision plus comprehensive 

insurance in 2006 as $448. The average value of a new vehicle in 2006, according to the U.S. 

Department of Energy, was $22,651.3

 (This value is for a 2006 vehicle in 2006 and is used 

only for the insurance adjustment; it does not correspond to the new vehicle prices, described 

below, used in the vehicle sales impact calculation.) Dividing the insurance cost by the 

average price of a new vehicle gives the proportion of comprehensive plus collision insurance 

as 1.98% of the price of a vehicle. If this same proportion holds for the increase in price of a 

vehicle, then insurance costs should go up by 1.98% of the increase in vehicle cost. For the 

five-year period, the present value of this increase in insurance cost would be worth 9.0% of 

the vehicle cost increase, using a 3% discount rate (8.1% at a 7% discount rate). 

Calculating the average increase in sales tax starts with the vehicle sales tax for each 

state in 2006.4

 The sales tax per state was then multiplied by the 2006 population of the 

state;5

 those values were summed and divided by total U.S. population, to give a population-
Draft Regulatory Impact Analysis 

8-2 

weighted sales tax. That estimate of the state sales taxes for vehicles in the U.S. is 5.3% in 

2006. This value is assumed to be a one-time cost incurred when the vehicle is purchased. 

As of August 24, 2009, the national average interest rate for a 5 year new car loan was 

7.41 percent.6

 Converting the up-front payment to an annual value paid over five years results 

in a consumer paying 24.7% of the up-front amount every year. The present value of these 

five payments results in an increase of 12.9% of the cost, using a 3% discount rate; with a 7% 

discount rate, the increase is 1.1%. NHTSA’s PRIA notes that 70% of auto purchases use 

financing; applying that fraction to this cost increase results in an addition of 9.0% in 

financing costs with a 3% discount rate, and 0.8% for a 7% discount rate. 

The average resale price of a vehicle after 5 years is about 35%7

 of the original 

purchase price. Because the consumer can recover that amount after 5 years, it reduces the 

effect of the increased cost of the vehicle. Discounted to a present value at a 3% interest rate, 

the increase in price should be worth about 30.2% to the vehicle purchaser (25.0% at a 7% 

discount rate). This approach is premised on the idea that the resale value of a vehicle is 

directly proportional to the initial value, and that proportion does not change. 

Thus, the effect on a consumer’s expenditure of the cost of the new technology (with 

some rounding) should be (1 + 0.090 + 0.053 + 0.090 – 0.302) = 0.932 times the cost of the 

technology at a 3% discount rate. At a 7% discount rate, the effect on a consumer’s 

expenditure of the cost of the new technology should be (1 + 0.081 + 0.053 + 0.008 – 0.250) 

= 0.892 times the cost of the technology. 

The fuel cost savings are based on the five years of consumer ownership of the 

vehicle. The analysis is done for each model-year for an average vehicle. Section 5.6 of this 

DRIA discusses the source of aggregate fuel savings, in gallons, for cars and trucks for each 

model year by year. These values are divided by the total number of the vehicles produced to 

get per-vehicle savings per year for the first five years of the vehicle’s life. This method 

ignores the few vehicles of the new model year that are scrapped. Because incorporating 

scrappage would reduce the denominator, and thus increase per-vehicle fuel savings, it 

underestimates per-vehicle fuel savings by a small amount. The per-vehicle fuel savings in 

gallons are multiplied by the price of fuel to get the per-vehicle fuel savings in dollars. For 

each model year, then, the first five years of fuel savings are discounted and summed to 

produce the present value of fuel savings for that vintage vehicle. For instance, the 2016 fuel 

savings per vehicle are the present value in year 2016 of fuel savings estimated for 2016 

through 2020. 

The prices for new vehicles are assumed to be constant at the 2008 value (in 2007$) of 

$26,201 for a car, and $29,678 for a truck. These are the values used in NHTSA’s 2011 rule 

on CAFE standards. 

The fuel cost savings are subtracted from the increase in costs associated with the rule 

to get the net effect of the rule on consumer expenditure. The higher cost leads consumers to 

purchase fewer new vehicles, but the fuel savings can counteract this effect. This calculation 

uses an elasticity of demand for new vehicles of -18

: that is, an increase of 1% in the price of 

a new vehicle will lead to a 1% reduction in new vehicle sales. Using this value assumes that 
Other Economic and Social Impacts 

8-3 

the demand elasticity for new vehicles under this rule is the same as the elasticity for older 

vehicles. This change in consumer expenditure as a percent of the average price of a new 

vehicle, with the elasticity of demand of -1, is the negative of the percent change in vehicle 

purchases. The net effect of this calculation on vehicle purchases is in Table 8-1 and Table 

8-2.

Table 8-1 Vehicle Sales Impacts Using a 3% Discount Rate

CHANGE IN 

CAR SALES 

% CHANGE CHANGE IN 

TRUCK SALES 

% CHANGE 

2012 66,600 0.7 27,300 0.5 

2013 93,300 0.9 161,300 2.8 

2014 134,400 1.3 254,400 4.4 

2015 236,300 2.2 368,400 6.5 

2016 375,400 3.4 519,000 9.4 

Table 8-1shows vehicle sales increasing. Because the fuel savings associated with this 

rule are expected to exceed the technology costs, the effective prices of vehicles – the 

adjusted increase in technology cost less the fuel savings over five years -- to consumers will 

fall, and consumers will buy more new vehicles. This effect is expected to increase over time. 

As a result, if consumers consider fuel savings at the time that they make their vehicle 

purchases, the lower net cost of the vehicles is expected to lead to an increase in sales for both 

cars and trucks. Both the absolute and the percent increases for truck sales are larger than 

those for cars (except in 2012). 

Table 8-2 Vehicle Sales Impacts Using a 7% Discount Rate

CHANGE IN 

CAR SALES 

% CHANGE CHANGE IN 

TRUCK SALES 

% CHANGE 

2012 61,900 0.7 25,300 0.5 

2013 86,600 0.9 60,000 1 

2014 125,200 1.2 122,900 2.1 

2015 221,400 2 198,100 3.5 

2016 353,100 3.2 291,500 5.3 

Table 8-2 shows the same calculations using a 7% discount rate. Qualitatively, the 

results are identical to those using a 3% discount rate: the fuel savings outweigh the increase 

in technology costs for all years. As a result, vehicle sales are expected to be higher under 

this rule than in the absence of the rule. In addition, while the increased numbers of car sales 

are larger than the numbers for trucks, the percent increases are larger for trucks. 

This calculation focuses on changes in consumer expenditures as the explanatory 

variable for changes in aggregate new vehicle sales. This is a simplification, since consumers 

typically consider a number of factors in addition to expenditures when they decide on 

purchasing a vehicle. In addition, it does not consider changes in the mix of vehicles sold that 
Draft Regulatory Impact Analysis 

8-4 

may result from this rule. The next section discusses more complex modeling of the vehicle 

purchase decision. 

8.1.2 Consumer Vehicle Choice Modeling 

In this section we describe some of the consumer vehicle choice models EPA has 

reviewed in the literature, and we describe the models’ results and limitations that we have 

identified. The evidence from consumer vehicle choice models indicates a huge range of 

estimates for consumers’ willingness to pay for additional fuel economy. Because consumer 

surplus estimates from consumer vehicle choice models depend critically on this value, we 

would consider any consumer surplus estimates of the effect of our rule from such models to 

be unreliable. In addition, the predictive ability of consumer vehicle choice models may be 

limited. While vehicle choice models are based on sales of existing vehicles, vehicle models 

are likely to change, both independently and in response to this proposed rule. The models 

may not predict well in response to these changes. Instead, we compare the value of the fuel 

savings associated with this rule with the increase in technology costs. Like NHTSA, EPA 

will continue its efforts to review the literature, but, given the known difficulties, neither 

NHTSA nor EPA has conducted an analysis using these models for this proposal. 

This rule will lead automakers to change characteristics – in particular, the fuel 

economy -- of the vehicles they produce. These changes will affect the cost of manufacturing 

the vehicle; as a result, the prices of the vehicles will also change. 

In response to these changes, the number and types of vehicles sold is likely to change. 

When consumers buy vehicles, they consider both their personal characteristics (such as age, 

family composition, income, and their vehicle needs) and the characteristics of vehicles (e.g., 

vehicle size, fuel economy, and price). In response to the changes in vehicle characteristics, 

consumers will reconsider their purchases. Increases in fuel economy are likely to be 

attractive to consumers, but increases in price, as well as some changes in other vehicle 

characteristics, may be deterrents to purchase. As a result, consumers may choose a different 

vehicle than they would have purchased in the absence of the rule. The changes in prices and 

vehicle characteristics are likely to influence consumers on multiple market scales: the total 

number of new vehicles sold; the mix of new vehicles sold; and the effects of the sales on the 

used vehicle market. 

Consumer vehicle choice modeling (CCM) is a method used to predict what vehicles 

consumers will purchase, based on vehicle characteristics and prices. In principle, it should 

produce more accurate estimates of compliance costs compared to models that hold fleet mix 

constant, since it predicts changes in the fleet mix that can affect compliance costs. It can also 

be used to measure changes in consumer surplus, the benefit that consumers perceive from a 

good over and above the purchase price. (Consumer surplus is the difference between what 

consumers would be willing to pay for a good, represented by the demand curve, and the 

amount they actually pay. For instance, if a consumer were willing to pay $30,000 for a new 

vehicle, but ended up paying $25,000, the $5000 difference is consumer surplus.) 

A number of consumer vehicle choice models have been developed. They vary in the 

methods used, the data sources, the factors included in the models, the research questions they 
Other Economic and Social Impacts 

8-5 

are designed to answer, and the results of the models related to the effects of fuel economy on 

consumer decisions. This section will give some background on these differences among the 

models. 

8.1.2.1 Methods 

Consumer choice models (CCMs) of vehicle purchases typically use a form of discrete 

choice modeling. Discrete choice models seek to explain discrete rather than continuous 

decisions. An example of a continuous decision is how many pounds of food a farm might 

grow: the pounds of food can take any numerical value. Discrete decisions can take only a 

limited set of values. The decision to purchase a vehicle, for instance, can only take two 

values, yes or no. Vehicle purchases are typically modeled as discrete choices, where the 

choice is whether to purchase a specified vehicle. The result of these models is a prediction 

of the probability that a consumer will purchase a specified vehicle. A minor variant on 

discrete choice models estimates the market share for each vehicle. Because the market share 

is, essentially, the probability that consumers will purchase a specific vehicle, these 

approaches are similar in process; they differ mostly in the kinds of data that they use. 

The primary methods used to model vehicle choices are nested logit and mixed logit. 

In a nested logit, the model is structured in layers. For instance, the first layer may be the 

choice of whether to buy a new or used vehicle. Given that the person chooses a new vehicle, 

the second layer may be whether to buy a car or a truck; given that the person chooses a car. 

The third layer may be the choice among an economy, midsize, or luxury car. Examples of 

nested logit models include Goldberg,9

 Greene et al.,10 and McManus.11

In a mixed logit, personal characteristics of consumers play a larger role than in nested 

logit. While nested logit can look at the effects of a change in average consumer 

characteristics, mixed logit allows consideration of the effects of the distribution of consumer 

characteristics. As a result, mixed logit can be used to examine the distributional effects on 

various socioeconomic groups, which nested logit is not designed to do. Examples of mixed 

logit models include Berry, Levinsohn, and Pakes,12 Bento et al.,13 and Train and Winston.14 

While discrete choice modeling appears to be the primary method for consumer choice 

modeling, others (such as Kleit15 and Austin and Dinan16) have used a matrix of demand 

elasticities to estimate the effects of changes in cost. The discrete choice models can produce 

such elasticities. Kleit as well as Austin and Dinan used the elasticities from an internal GM 

vehicle choice model. 

8.1.2.2 Data Sources 

The predictions of vehicle purchases from CCMs are based on consumer and vehicle 

characteristics. The CCMs identify the effects of changing the characteristics on the purchase 

decisions. These effects are typically called the parameters or coefficients of the models. For 

instance, the model parameters might predict that an increase in a person’s income of 10% 

would increase the probability of her purchasing vehicle A by 5%, and decrease the 

probability of her purchasing vehicle B by 10%. 
Draft Regulatory Impact Analysis 

8-6 

The parameters in CCMs can be developed either from original data sources 

(estimated models), or using values taken from other studies (calibrated models). 

Estimated models use datasets on consumer purchase patterns, consumer 

characteristics, and vehicle characteristics to develop their original sets of parameters. The 

datasets used in these studies sometimes come from surveys of individuals’ behaviors.17 

Because they draw on the behavior of individuals, they provide what is sometimes called 

micro-level data. Other studies, that estimate market shares instead of discrete purchase 

decisions, use aggregated data that can cover long time periods.18 

Calibrated models rely on existing studies for their parameters. Researchers may draw 

on results from a number of estimated models, or even from research other than CCM, to 

choose the parameters of the models. The Fuel Economy Regulatory Analysis Model 

developed for the Energy Information Administration19 and the New Vehicle Market Model 

developed by NERA Economic Consulting20 are examples of calibrated models. 

8.1.2.3 Factors Included in the Models 

Consumer choice models vary in their complexity and levels of analysis. Some focus 

only on the new vehicle market;21 others consider the choice between new vehicles and an 

outside good (possibly including a used vehicle);22 others explicitly consider the relationship 

between the new and used vehicle markets.23 Some models include consideration of vehicle 

miles traveled,24 though most do not. 

The models vary in their inclusion of both consumer and vehicle information. One 

model includes only vehicle price and the distribution of income in the population influencing 

choice;25 others include varying numbers and kinds of vehicle and consumer attributes. 

8.1.2.4 Research Questions for the Models 

Consumer choice models have been developed to analyze many different research and 

policy questions. In part, these models have been developed to advance the state of economic 

modeling. The work of Berry, Levinsohn, and Pakes,26 for instance, is often cited outside the 

motor vehicle context for its incorporation of multiple new modeling issues into its 

framework. In addition, because the vehicle sector is a major part of the U.S. economy and a 

stakeholder in many public policy discussions, research questions cover a wide gamut. These 

topics have included the effects of voluntary export restraints on Japanese vehicles compared 

to tariffs and quotas,27 the market acceptability of alternative-fuel vehicles,28 the effects of 

introduction and exit of vehicles from markets,29 causes of the decline in market shares of 

U.S. automakers,30 and the effects of gasoline taxes31 and “feebates”32 (subsidizing fuelefficient cars with revenue collected by taxing fuel-inefficient vehicles). 

8.1.2.5 The Effect of Fuel Economy on Consumer Decisions 

Consumer vehicle choice models typically consider the effect of fuel economy on 

vehicle purchase decisions. It can appear in various forms. 
Other Economic and Social Impacts 

8-7 

Some models33 incorporate fuel economy through its effects on the cost of owning a 

vehicle. With assumptions on the number of miles traveled per year and the cost of fuel, it is 

possible to estimate the fuel savings (and perhaps other operating costs) associated with a 

more fuel-efficient vehicle. Those savings are considered to reduce the cost of owning a 

vehicle: effectively, they reduce the purchase price. This approach relies on the assumption 

that, when purchasing vehicles, consumers can estimate the fuel savings that they expect to 

receive from a more fuel-efficient vehicle and consider the savings equivalent to a reduction 

in purchase price. Turrentine and Kurani34 question this assumption; they find, in fact, that 

consumers do not make this calculation when they purchase a vehicle. The question remains, 

then, how or whether consumers take fuel economy into account when they purchase their 

vehicles. 

Most estimated consumer choice models, instead of making assumptions about how 

consumers incorporate fuel economy into their decisions, use data on consumer behavior to 

identify that effect. In some models, the miles per gallon of vehicles is one of the vehicle 

characteristics included to explain purchase decisions. Other models use fuel consumption 

per mile, the inverse of miles per gallon, as a measure:35 since consumers pay for gallons of 

fuel, then this measure can assess fuel savings relatively directly.36 Yet other models multiply 

fuel consumption per mile by the cost of fuel to get the price of driving a mile,37 or they 

divide fuel economy by fuel cost to get miles per dollar.38 It is worth noting that these last 

two measures assume that consumers respond the same way to an increase in fuel economy as 

they do to a decrease in the price of fuel when each has the same effect on cost per mile 

driven. On the one hand, while this assumption does not rely on as complex a calculation as 

the present value of fuel savings that Turrentine and Kurani examined, it suggests a 

calculating consumer. On the other hand, it is also a way to recognize the role of fuel prices 

in consumers’ purchase of fuel economy: Busse et al.39 present results that higher fuel prices 

play a major role in that decision. 

Greene and Liu,40 in a paper published in 1988, reviewed 10 papers using consumer 

vehicle choice models and estimated for each one how much consumers would be willing to 

pay at time of purchase to reduce vehicle operating costs by $1 per year. They found that 

people were willing to pay between $0.74 and $25.97 for a $1 decrease in annual operating 

costs for a vehicle. This is clearly a very wide range: while the lowest estimate suggests that 

people are not willing to pay $1 once to get $1 per year reduced costs of operating their 

vehicles, the maximum suggests a willingness to pay 35 times as high. For comparison, the 

present value of saving $1 per year for 15 years at a 3% discount rate is $11.94, while a 7% 

discount rate produces a present value of $8.78. While this study is quite old, it suggests that, 

at least as of that time, consumer vehicle choice models produced widely varying estimates of 

the value of reduced vehicle operating costs. 

More recent studies do not suggest agreement on the value of increased fuel economy 

to consumers. For instance, some papers41 find that the role of fuel cost (price per gallon 

divided by miles per gallon, or the cost of driving one mile) decreases for larger vehicles; in 

contrast, Gramlich42 finds that owners of fuel-inefficient vehicles have the greatest 

willingness to pay for improved fuel economy. Part of the difficulty may be, as these papers 

note, that fuel economy may be correlated (either positively or negatively) with other vehicle 

attributes, such as size, power, or quality, not all of which may be included in the analyses; as 
Draft Regulatory Impact Analysis 

8-8 

a result, “fuel economy” may in fact represent several characteristics at the same time. 

Indeed, Gramlich43 includes both fuel cost (dollars per mile) and miles per gallon in his 

analysis, with the argument that miles per gallon measures other undesirable quality 

attributes, while fuel cost picks up the consumer’s demand for improved fuel economy. 

Espey and Nair44 find, using data from model year 2001, that consumers might be 

willing to pay roughly $500 for a 1-mpg increase in city driving, approximately $250 for a 1-

mpg increase in highway driving, or approximately $600 for an increase in combined fuel 

economy; they argue that these values approximately correspond to the fuel savings that 

consumers might expect over the lifetime of the vehicle. McManus45 finds, in 2005, that 

consumers were willing to pay $578 for a 1-mpg increase in fuel economy. Gramlich46 finds 

willingness to pay for an increase from 25 mpg to 30 mpg to range between $4100 (for luxury 

cars, when gasoline costs $2/gallon) to $20,600 (for SUVs when gasoline costs $3.50/gallon). 

Some studies47 argue that automakers could increase profits by increasing fuel 

economy because the amount that consumers are willing to pay for increased fuel economy 

outweighs the costs of that improvement. Other studies48 have found that increasing fuel 

economy standards imposes welfare losses on consumers and producers, because consumers 

should already be buying as much fuel economy as they want. In the course of reaching this 

result, though, at least one of these studies49 notes that its baseline model implies that 

consumers are willing to buy more fuel economy than producers have provided; they have to 

adjust their model to eliminate these “negative-cost” fuel economy improvements. 

The models do not appear to yield very consistent results on the role of fuel economy 

in consumer and producer decisions. 

8.1.2.6 Why Consumers May Not Buy, and Producers May Not Provide, Fuel 

Economy that Pays for Itself 

If consumers are willing to pay for fuel-saving technologies, why does the market not 

already take advantage of these low-cost technologies? Why aren’t consumers demanding 

these vehicle improvements, and manufacturers supplying them, when they appear to “pay for 

themselves” even in the absence of regulation? 

On the consumer side, this disconnect between net present value estimates of energyconserving cost savings and what consumers actually spend on energy conservation is often 

referred to as the Energy Paradox,50 since consumers appear to routinely undervalue a wide 

range of investments in energy conservation. Some possible explanations for the paradox 

include: 

 Consumers put little weight on benefits from fuel savings in the future; 

 Consumers consider other attributes more important than fuel economy at the time 

of vehicle purchase; 

 Consumers may not be able to find the vehicles they want with improved fuel 

economy; 
Other Economic and Social Impacts 

8-9 

 Consumers have difficulty in calculating expected fuel savings; 

 Consumers may use imprecise rules of thumb when deciding how much fuel 

economy to purchase; 

 Fuel savings in the future are uncertain; in contrast, at the time of purchase the 

increased costs of fuel-saving technologies are certain and immediate; 

 There is likely to be variation among consumers in the benefits they get from 

improved fuel economy, due to different miles driven and driving styles. 

The producer side of this paradox is much less studied. Hypotheses for 

underprovision of fuel economy by producers include: 

 Producers put more effort into attributes that consumers have regularly sought in 

the past, such as size and power, rather than fuel savings with uncertain future 

returns; 

 In selecting a limited number of vehicle attributes among which consumers can 

choose, producers may aim to provide choices related to characteristics (such as 

numbers of doors or transmission types) that strongly influence what vehicle a 

consumer will buy, and fuel economy may not make that list; 

 While consumer preferences for fuel economy may change rapidly as fuel prices 

fluctuate, producers cannot change their design or production decisions as rapidly; 

as a result, vehicle designs may end up not satisfying consumer desires at a 

particular time; 

 Producers may have misestimated the value that consumers place on fuel 

economy. 

How consumers buy, and producers provide, fuel economy involves complex 

decisions on both sides of the market. Both sides of the market rely heavily in their 

calculations on the uncertain benefits of fuel savings. In addition, consumers trade off fuel 

economy with many other vehicle attributes, and producers do not provide the full range of 

attributes possible for consumers. From this perspective, it may not be a surprise that, at a 

given point in time, consumer preferences for fuel economy may not match up with producer 

provision of it. 

8.1.2.7 Assessment of the Literature 

Consumer vehicle choice modeling in principle can provide a great deal of useful 

information for regulatory analysis. All models estimate changes in fleet mix of new 

vehicles; some also provide estimates of total new vehicle sales; and a few incorporate the 

used vehicle market, potentially to the decision on when a vehicle is scrapped. Being able to 

model these changes has several advantages. 
Draft Regulatory Impact Analysis 

8-10 

First, consumer vehicle choice modeling has the potential to describe more accurately 

the impact of a policy, by identifying market shifts. More accurate description of the market 

resulting from a policy can improve other estimates of policy impacts, such as the change in 

vehicle emissions or vehicle miles traveled. The predictive ability of models, though, is not 

proven. It is likely that, in coming years, new vehicles will be developed, and existing 

vehicles will be redesigned, perhaps to have improvements in both fuel economy and safety 

factors in combinations that consumers have not previously been offered. Welch,51 for 

instance, argues that auto producers are likely to increase the sizes of vehicles in response to 

the footprint-based fuel economy standard. Models based on the existing vehicle fleet may, 

however, not do well in predicting consumers’ choices among the new vehicles offered. One 

attempt to analyze the effect of the oil shock of 1973 on consumer vehicle choice found that, 

after two years, the particular model did not predict well due to changes in the vehicle fleet.52 

Thus, consumer vehicle choice models, even if they did produce robust results in analyzing 

the short-term effects of policy changes, may miss changes associated with new and 

redesigned vehicles. 

The modeling may improve estimates of the compliance costs of a rule. Most current 

modeling is based on a fleet mix determined outside the model; neither vehicle manufacturers 

nor consumers respond directly to cost increases and other vehicle changes by a change in the 

fleet mix. With the use of consumer vehicle choice modeling, both consumers and producers 

have greater choices in response to these changes: they can either accept the new costs and 

vehicle characteristics, or they can change which vehicles are sold. The fact that consumers 

and producers have additional options suggests that compliance costs are likely to be lower 

through incorporation of a consumer choice model than through use of a technology-cost 

model alone. On the other hand, the effect may not be large: in the context of “feebates” 

(subsidizing fuel-efficient cars with revenue collected by taxing fuel-inefficient vehicles), 

Greene et al. found that 95% of the increase in fuel economy was due to addition of 

technology rather than changes in vehicles sold.53 Consideration of consumer behavior in 

welfare estimates will improve regulatory analysis, but only to the extent that the predicted 

changes in consumer purchase patterns reflect actual changes. 

An additional feature of consumer choice models, as noted above, is that they can be 

used to calculate consumer surplus impacts. Consumer surplus is a standard measurement of 

consumer impacts in benefit-cost analysis. Consumer surplus calculations from these models 

estimate how much consumers appreciate the gains in fuel economy relative to the increased 

vehicle costs that they face, based on the assumption that consumers, at the time of vehicle 

purchase, have made the best decisions for themselves on the amount of fuel economy in the 

vehicles they purchase. These values, though, are based on the relationship between 

consumer willingness to pay for fuel economy and the costs of improved fuel economy. 

Because the estimates of consumer willingness to pay for fuel economy appear to be highly 

inconsistent, consumer surplus measures from any one model are unlikely to be reliable. 

At this point, it is unclear whether two models given the same scenario would produce 

similar results in either prediction of changes in the vehicles purchased or in estimates of 

consumer surplus effects. The estimates of consumer surplus from consumer vehicle choice 

models depend heavily on the value to consumers of improved fuel economy, a value for 

which estimates are highly varied. In addition, the predictive ability of consumer vehicle 
Other Economic and Social Impacts 

8-11 

choice models may be limited as consumers face new vehicle choices that they previously did 

not have. If the results across models are not consistent or are highly sensitive to parameters 

or other features, then careful thought needs to be given to model selection and development. 

Nonetheless, because there are potential advantages to using consumer vehicle choice 

models if these difficulties can be addressed, EPA is continuing to explore options for 

including consumer and producer choice in modeling the impacts of fuel economy-related 

regulations. This effort includes further review of existing consumer vehicle choice models 

and the estimates of consumers’ willingness to pay for increased fuel economy. In addition, 

EPA is developing capacity to examine the factors that may affect the results of consumer 

vehicle choice models, and to explore their impact on analysis of regulatory scenarios. Under 

contract with EPA, Resources for the Future (RFF) is developing a model of the vehicle 

market that can be used to evaluate different policy designs and compare regulatory scenarios 

on the basis of changes in cost, changes in the prices paid by consumers, changes in consumer 

welfare, and changes in industry profits. It should help to shed light on whether it is more 

costly to rely solely on the application of technologies to vehicles to meet a given fuel 

standard than when consumer and producer behavior is taken into account. EPA plans to 

evaluate this work within the context of the overall literature on consumer vehicle choices, to 

determine its usefulness in informing the analysis for the final rule. We seek comment on the 

usefulness of consumer choice modeling results and the consistency and reliability of results 

from these models. 

8.1.3 Consumer Payback Period and Lifetime Savings on New Vehicle Purchases 

Another factor of interest is the payback period on the purchase of a new vehicle that 

complies with the proposed standards. In other words, how long would it take for the 

expected fuel savings to outweigh the increased cost of a new vehicle? For example, a new 

2016 MY vehicle is estimated to cost $1,050 more (on average, and relative to the reference 

case vehicle) due to the addition of new GHG reducing technology (see Chapter 4 for details 

on this cost estimate). This new technology will result in lower fuel consumption and, 

therefore, savings in fuel expenditures (see Chapter 5 for details on fuel savings). But how 

many months or years would pass before the fuel savings exceed the upfront cost of $1,050? 

Table 8-3 provides the answer to this question for a vehicle purchaser who pays for the 

new vehicle upfront in cash (we discuss later in this section the payback period for consumers 

who finance the new vehicle purchase with a loan). The table uses annual miles driven 

(vehicle miles traveled, or VMT) and survival rates consistent with the emission and benefits 

analyses presented in Chapter 4 of the draft joint TSD. We have included rebound VMT in 

the control case but not in the reference case, consistent with other parts of our analysis. We 

have also included fuel savings associated with A/C controls (in the control case only), but 

have not included expected A/C-related maintenance savings. We discuss the likely 

maintenance savings in Chapter 2 of this DRIA. Further, this analysis does not include other 

societal impacts such as the value of increased driving, or noise, congestion and accidents 

since we really want to focus on those factors consumers consider most while in the 

showroom considering a new car purchase. Car/truck fleet weighting is handled as described 
Draft Regulatory Impact Analysis 

8-12 

in Chapter 1 of the draft joint TSD. As can be seen in the table, it will take under 3 years (2 

years and 8 months at a 3% discount rate, 2 years and 10 months at a 7% discount rate) for the 

cumulative fuel savings to exceed the upfront increase in vehicle cost. For the average driver, 

this payback would occur at around 46,000 to 48,000 miles, depending on the discount rate. 

For the driver that drives more than the average, the payback would come sooner. For the 

driver that drives less than the average, the payback would come later. 

Table 8-3 Payback Period on a 2016MY New Vehicle Purchase via Cash (2007 dollars) 

Increased 

Vehicle 

Costa

Fuel 

Priceb

Reference 

VMTc

Control 

VMTc

Reference 

Fuel 

Costsd

Control 

Fuel 

Costsd

Annual 

Fuel 

Savings 

Cumulative 

Discounted 

Fuel 

Savings at 

3% 

Cumulati

Discount

Fuel 

Savings 

Year of 7% 

Ownership ($) ($/gal) (miles) (miles) ($) ($) ($) ($) ($) 

1 -$1,128 $3.27 17,481 17,813 $2,544 $2,101 $443 $436 $428

2 $3.39 16,934 17,256 $2,549 $2,106 $444 $860 $829

3 $3.48 16,432 16,744 $2,545 $2,102 $443 $1,272 $1,203

4 $3.56 15,777 16,077 $2,495 $2,061 $434 $1,663 $1,546 a

 Increased cost of the proposed rule is $1,050; the value here includes nationwide average sales tax of 5.3% and increased insurance 

premiums of 1.98%; both of these percentages are discussed in section 8.1.1. 

b

 AEO 2009 reference case fuel price including taxes. 

c

 VMT is calculated as the weighted car/truck VMT with cars estimated to account for 67% of the fleet and trucks 33%; VMT shown 

here includes survival fraction and, for the control case, rebound VMT. 

d

 Fuel costs calculated using the reference and control case achieved CO2 levels as presented in Chapter 5 with 8887 grams of CO2 p

gallon of gasoline and include the 20 percent road fuel economy gap, as discussed in Chapter 5; the control case also includes the 

effects of A/C controls on CO2 emissions but not the expected A/C-related maintenance savings.

Most people purchase a new vehicle using credit rather than paying cash up front. The 

typical car loan today is a five year, 60 month loan. As of August 24, 2009, the national 

average interest rate for a 5 year new car loan was 7.41 percent. If the increased vehicle cost 

is spread out over 5 years at 7.41 percent, the analysis would look like that shown in Table 

8-4. As can be seen in this table, the fuel savings immediately outweigh the increased 

payments on the car loan, amounting to $162 in discounted net savings (3% discount rate) 

saved in the first year and similar savings for the next two years before reduced VMT starts to 

cause the fuel savings to fall. Results are similar using a 7% discount rate. This means that 

for every month that the average owner is making a payment for the financing of the average 

new vehicle their monthly fuel savings would be greater than the increase in the loan 

payments. This amounts to a savings on the order of $9 to $14 per month throughout the 

duration of the 5 year loan. Note that in year six when the car loan is paid off, the net 

savings equal the fuel savings (as would be the case for the remaining years of ownership). 
Other Economic and Social Impacts 

8-13 

Table 8-4 Payback Period on a 2016 MY New Vehicle Purchase via Credit (2007 dollars) 

Increased 

Vehicle 

Costa

Fuel 

Priceb

Reference 

VMTc

Control 

VMTc

Reference 

Fuel 

Costsd

Control 

Fuel 

Costsd

Annual 

Fuel 

Savings 

Annual 

Discounted 

Net 

Savings at 

3% 

Annua

Discount

Net 

Savings 

Year of 7% 

Ownership ($) ($/gal) (miles) (miles) ($) ($) ($) ($) ($) 

1 $278 $3.27 17,481 17,813 $2,544 $2,101 $443 $162 $159

2 $278 $3.39 16,934 17,256 $2,549 $2,106 $444 $158 $150

3 $278 $3.48 16,432 16,744 $2,545 $2,102 $443 $153 $139

4 $278 $3.56 15,777 16,077 $2,495 $2,061 $434 $141 $123

5 $278 $3.62 15,109 15,396 $2,432 $2,009 $423 $127 $107

6 $3.64 14,338 14,611 $2,318 $1,914 $403 $343 $278 a

 This uses the same increased cost as Table 8-3 but spreads it out over 5 years assuming a 5 year car loan at 7.41 percent. b

 AEO 2009 reference case fuel price including taxes. 

c

 VMT is calculated as the weighted car/truck VMT with cars estimated to account for 67% of the fleet and trucks 33%; VMT shown 

here includes survival fraction and, for the control case, rebound VMT. 

d

 Fuel costs calculated using the reference and control case achieved CO2 levels as presented in Chapter 5 with 8887 grams of CO2 p

gallon of gasoline and include the 20 percent road fuel economy gap, as discussed in Chapter 5; the control case also includes the 

effects of A/C controls on CO2 emissions but not the expected A/C-related maintenance savings.

We can also calculate the lifetime fuel savings and net savings for those who purchase the vehicle using 

cash and for those who purchase the vehicle with credit. This calculation applies to the vehicle owner who 

retains the vehicle for its entire life and drives the vehicle each year at the rate equal to the national 

projected average. The results are shown in Table 8-5. In either case, the present value of the lifetime net 

savings is greater than $3,200 at a 3% discount rate, or $2,400 at a 7% discount rate.Table 8-5 Lifetime 

Discounted Net Savings on a 2016 MY New Vehicle Purchase (2007 dollars) 

Increased 

Discounted Vehicle 

Cost 

Lifetime 

Discounted Fuel 

Savingsb,c 

Lifetime 

Discounted Net 

Savings 

Purchase Option ($) ($) ($) 

3% discount rate 

Cash $1,128 $4,558 $3,446 

Credita $1,293 $4,558 $3,265 

7% discount rate 

Cash $1,128 $3,586 $2,495 

Credita $1,180 $3,586 $2,406 a

 Assumes a 5 year loan at 7.41 percent. 

b

 VMT is calculated as the weighted car/truck VMT with cars estimated to account for 

67% of the fleet and trucks 33%; VMT shown here includes survival fraction and, for 

the control case, rebound VMT. 

c

 Fuel savings here were calculated using AEO 2009 reference case fuel price 

including taxes. 
Draft Regulatory Impact Analysis 

8-14 

8.2

8.3 Energy Security Impacts 

This chapter will only describe the energy security analysis that was conducted 

beyond that described in Chapter 4.B.10 of the TSD. Additional analysis was conducted to 

provide inputs to EPA’s OMEGA model. For a detailed discussion of the development of the 

energy security estimates, please refer to Chapter 4.B.10 of the TSD. 

After the EPA-sponsored peer review of the Oak Ridge National Laboratory’s 

(ORNL) Energy Security Analysis was completed in 2008, ORNL, at EPA’s request, updated 

the analysis using values from the AEO 2009 rather than the 2007 values. The methodology 

used to update this analysis was the same one that was peer-reviewed.54 The results are 

shown in Table 8-6. ORNL estimated the energy security premium for 2015, 2020, and 2030. 

Since the AEO 2009 forecasts ends in 2030, EPA assumed that the post-2030 energy security 

premium did not change through 2040. 

Table 8-6 Energy Security Premium in 2015, 2020, 2030, and 2040 (2007$/Barrel) 

YEAR MONOPSONY 

(RANGE) 

MACROECONOMIC 

DISRUPTION/ADJUSTMENT 

COSTS (RANGE) 

TOTAL MID-POINT 

(RANGE) 

2015 $11.79 

($4.26 - $21.37) 

$6.70 

($3.11 - $10.67) 

$18.49 

($9.80 - $28.08) 

2020 $12.31 

($4.46 - $22.53) 

$7.62 

($3.77 - $12.46) 

$19.94 

($10.58 - $30.47) 

2030 $10.57 

($3.84 - $18.94) 

$8.12 

($3.90 - $13.04) 

$18.69 

($10.52 - $27.89) 

2040 $10.57 

($3.84 - $18.94) 

$8.12 

($3.90 - $13.04) 

$18.69 

($10.52 - $27.89) 

EPA linearly interpolated the values for the years 2016 through 2019, using the 2015 

and 2020 values as endpoints. EPA followed the same procedure to estimate the 2021 

through 2029 estimates, using the 2020 and 2030 values as endpoints. Post-2030, EPA 

assumed that the energy security estimate did not change. The final set of values that was 

used by the OMEGA model is shown in Table 8-7. 
Other Economic and Social Impacts 

8-15 

Table 8-7 Energy Security Premium Estimates for Years 2015-2040 (2007$/Barrel) 

YEAR MONOPSONY MACRO/DISRUPT TOTAL 

2015 $11.79 $6.70 $18.49 

2016 $11.89 $6.88 $18.78 

2017 $12.00 $7.07 $19.07 

2018 $12.10 $7.25 $19.36 

2019 $12.21 $7.44 $19.65 

2020 $12.31 $7.62 $19.94 

2021 $12.14 $7.67 $19.82 

2022 $11.96 $7.72 $19.69 

2023 $11.79 $7.77 $19.57 

2024 $11.61 $7.82 $19.44 

2025 $11.44 $7.87 $19.32 

2026 $11.27 $7.92 $19.19 

2027 $11.09 $7.97 $19.07 

2028 $10.92 $8.02 $18.94 

2029 $10.74 $8.07 $18.82 

2030 $10.57 $8.12 $18.69 

2031 $10.57 $8.12 $18.69 

2032 $10.57 $8.12 $18.69 

2033 $10.57 $8.12 $18.69 

2034 $10.57 $8.12 $18.69 

2035 $10.57 $8.12 $18.69 

2036 $10.57 $8.12 $18.69 

2037 $10.57 $8.12 $18.69 

2038 $10.57 $8.12 $18.69 

2039 $10.57 $8.12 $18.69 

2040 $10.57 $8.12 $18.69 

The total energy security benefits are derived from the estimated reductions in imports 

of finished petroleum products and crude oil using only the macroeconomic 

disruption/adjustment portion of the energy security premium price. These values are shown 

in Table 8-8.55 The reduced oil estimates were derived from the OMEGA model, as explained 

in Chapter 5 of EPA’s DRIA. EPA used the same assumption that NHTSA used in its 

Corporate Average Fuel Economy and CAFE Reform for MY 2008-2011 Light Trucks 

proposal, which assumed each gallon of fuel saved reduces total U.S. imports of crude oil or 

refined products by 0.95 gallons56 . Section 5.3 of this RIA contains a discussion regarding 

caveats for the fuel savings estimated due to implementation of this rule. Section III.H.8.b of 

the preamble contains a detailed discussion of how the monopsony and macroeconomic 

disruption/adjustment components were treated for this analysis. Note that if the monopsony 

effects were included in this analysis, they could be significant. 
Draft Regulatory Impact Analysis 

8-16 

Table 8-8 Total Annual Energy Security Benefits in 2015, 2020, 2030, and 2040 (Billions of 2007 dollars) 

YEAR BENEFITS 

2015 $0.59 

2020 $2.30 

2030 $4.81 

2040 $6.23 

8.4 Other Externalities 

There are other impacts associated with the proposed GHG emissions standards and 

associated reduced fuel consumption. Lower fuel consumption would, presumably, result in 

fewer trips to the filling station to refuel and, thus, time saved. The rebound effect, discussed 

in detail in Chapter 4 of the draft joint TSD, produces additional benefits to vehicle owners in 

the form of consumer surplus from the increase in vehicle-miles driven, but may also increase 

the societal costs associated with traffic congestion, motor vehicle crashes, and noise. These 

effects are likely to be relatively small in comparison to the value of fuel saved as a result of 

the proposed standards, but they are nevertheless important to include. We summarize the 

value of these other impacts in section 8.4.4 of this DRIA. Please refer to the draft joint TSD 

that accompanies this proposal for more information about these impacts and how EPA and 

NHTSA use them in their analyses. 

8.4.1 Reduced Refueling Time 

Improving the fuel economy of passenger cars and light-duty trucks may also increase 

their driving range before they require refueling. By reducing the frequency with which 

drivers typically refuel their vehicles and extending the upper limit of the range they can 

travel before requiring refueling, improving fuel economy provides some additional benefits 

to their owners. Alternatively, if manufacturers respond to improved fuel economy by 

reducing the size of fuel tanks to maintain a constant driving range, the resulting cost saving 

will presumably be reflected in lower vehicle sales prices. If manufacturers respond by doing 

so, this presumably reflects their judgment that the value to economic benefits to vehicle 

buyers from lower purchase prices exceeds that from extended refueling range. 

No direct estimates of the value of extended vehicle range are readily available, so this 

analysis calculates the reduction in the annual number of required refueling cycles that results 

from improved fuel economy, and applies DOT-recommended values of travel time savings to 

convert the resulting time savings to their economic value.57 

Weighted by the nationwide mix of urban (about 2/3) and rural (about 1/3) driving and 

average vehicle occupancy for all driving trips (1.6 persons), the DOT-recommended value of 

travel time per vehicle-hour is $24.00 (in 2006 dollars). We assume that the average tank 

refill is 55%, that the average fuel tank is 19.3 gallons, and that the average time to find and 

use a gas station is five minutes.58,59
Other Economic and Social Impacts 

8-17 

8.4.2 Value of Additional Driving 

The increase in travel associated with the rebound effect produces additional benefits 

to vehicle owners, which reflect the value to drivers and other vehicle occupants of the added 

(or more desirable) social and economic opportunities that become accessible with additional 

travel. As evidenced by the fact that they elect to make more frequent or longer trips when 

the cost of driving declines, the benefits from this added travel exceed drivers’ added outlays 

for the fuel it consumes (measured at the improved level of fuel economy resulting from 

stricter GHG standards ).60 The amount by which the benefits from this increased driving 

travel exceed its increased fuel costs measures the net benefits they receive from the 

additional travel, usually referred to as increased consumer surplus. 

EPA estimates the economic value of the increased consumer surplus provided by 

added driving using the conventional approximation, which is one half of the product of the 

decline in vehicle operating costs per vehicle-mile and the resulting increase in the annual 

number of miles driven. Because it depends on the extent of improvement in fuel economy, 

the value of benefits from increased vehicle use changes by model year 

We discuss the rebound effect in more detail in Chapter 4 of the draft joint TSD. 

Again, the negative effect that rebound driving has on the fuel consumption savings 

associated with the proposed GHG standards is included in the fuel economy savings 

presented in section 8.5 of this DRIA. Note that in section 8.4.4 below, where we present the 

benefit associated with rebound driving, we have used pre-tax fuel prices since those prices 

reflect the societal value of the driving. 

8.4.3 Noise, Congestion, and Accidents 

Although it provides some benefits to drivers, increased vehicle use associated with 

the rebound effect also contributes to increased traffic congestion, motor vehicle accidents, 

and highway noise. Depending on how the additional travel is distributed over the day and on 

where it takes place, additional vehicle use can contribute to traffic congestion and delays by 

increasing traffic volumes on facilities that are already heavily traveled during peak periods. 

These added delays impose higher costs on drivers and other vehicle occupants in the form of 

increased travel time and operating expenses. Because drivers do not take these added costs 

into account in deciding when and where to travel, they must be accounted for separately as a 

cost of the added driving associated with the rebound effect. 

Increased vehicle use due to the rebound effect may also increase the costs associated 

with traffic accidents. Drivers may take account of the potential costs they (and their 

passengers) face from the possibility of being involved in an accident when they decide to 

make additional trips. However, they probably do not consider all of the potential costs they 

impose on occupants of other vehicles and on pedestrians when accidents occur, so any 

increase in these “external” accident costs must be considered as another cost of additional 

rebound-effect driving. Like increased delay costs, any increase in these external accident 

costs caused by added driving is likely to depend on the traffic conditions under which it takes 

place, since accidents are more frequent in heavier traffic (although their severity may be 

reduced by the slower speeds at which heavier traffic typically moves). 
Draft Regulatory Impact Analysis 

8-18 

Finally, added vehicle use from the rebound effect may also increase traffic noise. 

Noise generated by vehicles causes inconvenience, irritation, and potentially even discomfort 

to occupants of other vehicles, to pedestrians and other bystanders, and to residents or 

occupants of surrounding property. Because these effects are unlikely to be taken into 

account by the drivers whose vehicles contribute to traffic noise, they represent additional 

externalities associated with motor vehicle use. Although there is considerable uncertainty in 

measuring their value, any increase in the economic costs of traffic noise resulting from added 

vehicle use must be included together with other increased external costs from the rebound 

effect. 

EPA relies on estimates of congestion, accident, and noise costs caused by 

automobiles and light trucks developed by the Federal Highway Administration to estimate 

the increased external costs caused by added driving due to the rebound effect.61 NHTSA 

employed these estimates previously in its analysis accompanying the MY 2011 final rule, 

and continues to find them appropriate for this analysis after reviewing the procedures used 

by FHWA to develop them and considering other available estimates of these values. They 

are intended to measure the increases in costs from added congestion, property damages and 

injuries in traffic accidents, and noise levels caused by automobiles and light trucks that are 

borne by persons other than their drivers (or “marginal” external costs). 

Updated to 2007 dollars, FHWA’s “Middle” estimates for marginal congestion, 

accident, and noise costs caused by automobile use amount to 5.2 cents, 2.3 cents, and 0.1 

cents per vehicle-mile (for a total of 7.6 cents per mile), while those for pickup trucks and 

vans are 4.7 cents, 2.5 cents, and 0.1 cents per vehicle-mile (for a total of 7.3 cents per 

mile).62, 63 These costs are multiplied by the annual increases in automobile and light truck 

use from the rebound effect to yield the estimated increases in congestion, accident, and noise 

externality costs during each future year. 

EPA uses a single value for both cars and trucks, as shown in Table 8-9. 

Table 8-9 $/mile Inputs used for External Costs 

EXTERNAL COSTS $/VMT 

Congestion $ 0.052 

Accidents $ 0.023 

Noise $ 0.001 

8.4.4 Summary of Other Externalities 

Table 8-10 summarizes the other economic impacts discussed in sections 8.4.1 

through 8.4.3. 
Other Economic and Social Impacts 

8-19 

Table 8-10. Estimated Economic Externalities Associated with the Proposed Light-Duty Vehicle GHG 

Program (Millions of 2007 dollars) 

YEAR REDUCED 

REFUELING 

VALUE OF 

INCREASED 

DRIVING 

ACCIDENTS, 

NOISE, 

CONGESTION 

ANNUAL 

QUANTIFIED 

BENEFITS 

2012 $100 $100 -$100 $200 

2013 $200 $400 -$200 $400 

2014 $500 $700 -$400 $800 

2015 $700 $1,200 -$700 $1,300 

2016 $1,100 $2,000 -$1,100 $2,000 

2017 $1,500 $2,700 -$1,400 $2,800 

2018 $1,800 $3,400 -$1,800 $3,500 

2019 $2,200 $4,200 -$2,100 $4,200 

2020 $2,500 $4,900 -$2,400 $5,000 

2021 $2,800 $5,500 -$2,700 $5,600 

2022 $3,100 $6,100 -$3,000 $6,200 

2023 $3,400 $6,700 -$3,300 $6,800 

2024 $3,700 $7,200 -$3,600 $7,300 

2025 $3,900 $7,700 -$3,900 $7,800 

2026 $4,200 $8,200 -$4,100 $8,300 

2027 $4,400 $8,600 -$4,300 $8,700 

2028 $4,600 $9,100 -$4,500 $9,200 

2029 $4,800 $9,800 -$4,700 $9,800 

2030 $4,900 $10,000 -$4,900 $10,000 

2031 $5,100 $10,400 -$5,000 $10,400 

2032 $5,200 $10,700 -$5,200 $10,800 

2033 $5,400 $11,100 -$5,300 $11,100 

2034 $5,500 $11,400 -$5,500 $11,500 

2035 $5,700 $11,800 -$5,600 $11,800 

2036 $5,800 $12,100 -$5,800 $12,200 

2037 $6,000 $12,500 -$5,900 $12,600 

2038 $6,100 $12,900 -$6,000 $12,900 

2039 $6,200 $13,200 -$6,200 $13,300 

2040 $6,400 $13,600 -$6,300 $13,700 

2041 $6,500 $14,000 -$6,500 $14,100 

2042 $6,700 $14,400 -$6,600 $14,500 

2043 $6,800 $14,800 -$6,800 $14,900 

2044 $7,000 $15,200 -$6,900 $15,300 

2045 $7,200 $15,700 -$7,100 $15,700 

2046 $7,300 $16,100 -$7,200 $16,200 

2047 $7,500 $16,600 -$7,400 $16,700 

2048 $7,700 $17,000 -$7,600 $17,100 

2049 $7,800 $17,500 -$7,800 $17,600 

2050 $8,000 $18,000 -$7,900 $18,100 

NPV, 3% $89,600 $184,700 -$88,200 $186,100 

NPV, 7% $41,000 $82,700 -$40,200 $83,500 
Draft Regulatory Impact Analysis 

8-20 

8.5 Summary of Costs and Benefits 

In this section we present a summary of costs, benefits, and net benefits of the 

proposal. We present fuel consumption impacts as negative costs of the vehicle program. 

Table 8-11 shows the estimated annual societal costs of the vehicle program for the 

indicated calendar years. The table also shows the net present values of those costs for the 

calendar years 2012-2050 using both a 3 percent and a seven percent discount rate. In this 

table, fuel savings are calculated using pre-tax fuel prices and are presented as negative costs 

associated with the vehicle program (rather than positive savings). 

Table 8-11 Estimated Societal Costs of the Light-Duty Vehicle GHG Program (Millions of 2007 dollars) 

COSTS 2020 2030 2040 2050 NPV, 3% NPV, 7% 

Vehicle Compliance Costs $18,000 $17,900 $19,300 $20,900 $390,000 $216,600

Fuel Savings a -$43,100 -$90,400 -$125,000 -$167,000 -$1,677,600 -$746,100

Quantified Annual Costs -$25,100 -$72,500 -$105,700 -$146,100 -$1,287,600 -$529,500 a

 Calculated using pre-tax fuel prices. 

Table 8-12 presents estimated annual societal benefits for the indicated calendar years. 

The table also shows the net present values of those benefits for the calendar years 2012-2050 

using both a 3 percent and a 7 percent discount rate. The table shows the benefits of reduced 

GHG emissions—and consequently the annual quantified benefits (i.e., total benefits)—for 

each of five interim SCC values considered by EPA. 

The interim SCC values are derived using several discount rates and include: 

 $5 (based on a 5% discount rate); 

 $10 (5% using Newell-Pizer adjustment);, 

 $20 (average SCC value from the average SCC estimates based on 5% and 

3%); 

 $34 (3%); 

 $56 (3% using Newell-Pizer adjustment). 

These interim SCC values are in 2007 dollars, and are based on a CO2 emissions change of 1 

metric ton in 2007. Section III.H.2.a of the Preamble provides a complete discussion about 

SCC and the interim set of values. 

Section III.H.2.a of the preamble to this rule also notes that there is a very high 

probability (very likely according to the IPCC) that the benefit estimates from GHG 

reductions are underestimates. One of the primary reasons is that models used to calculate 

SCC values do not include information about impacts that have not been quantified. 
Other Economic and Social Impacts 

8-21 

In addition, the total GHG reduction benefits presented below likely underestimate the 

value of GHG reductions because they were calculated using the marginal values for CO2

emissions. The impacts of non-CO2 emissions vary from those of CO2 emissions because of 

differences in atmospheric lifetimes and radiative forcing. As a result, the marginal benefit 

values of non-CO2 GHG reductions and their growth rates over time will not be the same as 

the marginal benefits measured on a CO2–equivalent scale. Marginal benefit estimates per 

metric ton of non- CO2 GHGs are currently unavailable, but work is on-going to monetize 

benefits related to the mitigation of other non-CO2 GHGs. 

Table 8-12 Use Estimated Societal Benefits Associated with the Proposed Light-Duty Vehicle GHG 

Program (Millions of 2007 dollars) 

BENEFITS 2020 2030 2040 2050 NPV, 3% NPV, 7% 

Reduced GHG Emissions at each assumed SCC value 

SCC 5% $1,200 $3,300 $5,700 $9,500 $69,200 $28,600 

SCC 5% Newell-Pizer $2,500 $6,600 $11,000 $19,000 $138,400 $57,100 

SCC from 3% and 5% $4,700 $12,000 $22,000 $36,000 $263,000 $108,500 

SCC 3% $8,200 $22,000 $38,000 $63,000 $456,900 $188,500 

SCC 3% Newell-Pizer $14,000 $36,000 $63,000 $100,000 $761,400 $314,200 

PM2.5 Related Benefitsa,b,c $1,400 $3,000 $4,600 $6,700 $59,800 $26,300 

Energy Security Impacts 

(price shock) $2,300 $4,800 $6,200 $7,800 $85,800 $38,800 

Reduced Refueling $2,500 $4,900 $6,400 $8,000 $89,600 $41,000 

Value of Increased Drivingd $4,900 $10,000 $13,600 $18,000 $184,700 $82,700 

Accidents, Noise, 

Congestion -$2,400 -$4,900 -$6,300 -$7,900 -$88,200 -$40,200 

Quantified Annual Benefits at each assumed SCC value 

SCC 5% $9,900 $21,100 $30,200 $42,100 $400,900 $177,200 

SCC 5% Newell-Pizer $11,200 $24,400 $35,500 $51,600 $470,100 $205,700 

SCC from 3% and 5% $13,400 $29,800 $46,500 $68,600 $594,700 $257,100 

SCC 3% $16,900 $39,800 $62,500 $95,600 $788,600 $337,100 

SCC 3% Newell-Pizer $22,700 $53,800 $87,500 $132,600 $1,093,100 $462,800 a Note that the co-pollutant impacts associated with the standards presented here do not include the full 

complement of endpoints that, if quantified and monetized, would change the total monetized estimate of rulerelated impacts. Instead, the co-pollutant benefits are based on benefit-per-ton values that reflect only human 

health impacts associated with reductions in PM2.5 exposure. Ideally, human health and environmental benefits 

would be based on changes in ambient PM2.5 and ozone as determined by full-scale air quality modeling. 

However, we were unable to conduct a full-scale air quality modeling analysis in time for the proposal. We 

intend to more fully capture the co-pollutant benefits for the analysis of the final standards. b The PM2.5-related benefits (derived from benefit-per-ton values) presented in this table are based on an 

estimate of premature mortality derived from the ACS study (Pope et al., 2002). If the benefit-per-ton estimates 

were based on the Six Cities study (Laden et al., 2006), the values would be approximately 145% (nearly twoand-a-half times) larger

c

 The PM2.5-related benefits (derived from benefit-per-ton values) presented in this table assume a 3% discount 

rate in the valuation of premature mortality to account for a twenty-year segmented cessation lag. If a 7% 

discount rate had been used, the values would be approximately 9% lower. 

d

 Calculated using pre-tax fuel prices. 

Table 8-13 presents estimated annual net benefits for the indicated calendar years. 

The table also shows the net present values of those net benefits for the calendar years 2012-
Draft Regulatory Impact Analysis 

8-22 

2050 using both a 3 percent and a 7 percent discount rate. The table includes the benefits of 

reduced GHG emissions—and consequently the annual net benefits—for each of five interim 

SCC values considered by EPA. As noted above, there is a very high probability (very likely 

according to the IPCC) that the benefit estimates from GHG reductions are underestimates 

because, in part, models used to calculate SCC values do not include information about 

impacts that have not been quantified. 

Table 8-13. Quantified Net Benefits Associated with the Proposed Light-Duty Vehicle GHG Programa, b

(Millions of 2007 dollars) 

 2020 2030 2040 2050 NPV, 3% NPV, 7% 

Quantified Annual 

Costs -$25,100 -$72,500 -$105,700 -$146,100 -$1,287,600 -$529,500 

Quantified Annual Benefits at each assumed SCC value 

SCC 5% $9,900 $21,100 $30,200 $42,100 $400,900 $177,200 

SCC 5% Newell-Pizer $11,200 $24,400 $35,500 $51,600 $470,100 $205,700 

SCC from 3% and 5% $13,400 $29,800 $46,500 $68,600 $594,700 $257,100 

SCC 3% $16,900 $39,800 $62,500 $95,600 $788,600 $337,100 

SCC 3% Newell-Pizer $22,700 $53,800 $87,500 $132,600 $1,093,100 $462,800 

Quantified Net Benefits at each assumed SCC value 

SCC 5% $35,000 $93,600 $135,900 $188,200 $1,688,500 $706,700 

SCC 5% Newell-Pizer $36,300 $96,900 $141,200 $197,700 $1,757,700 $735,200 

SCC from 3% and 5% $38,500 $102,300 $152,200 $214,700 $1,882,300 $786,600 

SCC 3% $42,000 $112,300 $168,200 $241,700 $2,076,200 $866,600 

SCC 3% Newell-Pizer $47,800 $126,300 $193,200 $278,700 $2,380,700 $992,300 a Note that the co-pollutant impacts associated with the standards presented here do not include the full 

complement of endpoints that, if quantified and monetized, would change the total monetized estimate of rulerelated impacts. Instead, the co-pollutant benefits are based on benefit-per-ton values that reflect only human 

health impacts associated with reductions in PM2.5 exposure. Ideally, human health and environmental benefits 

would be based on changes in ambient PM2.5 and ozone as determined by full-scale air quality modeling. 

However, we were unable to conduct a full-scale air quality modeling analysis in time for the proposal. We 

intend to more fully capture the co-pollutant benefits for the analysis of the final standards. b Fuel impacts were calculated using pre-tax fuel prices. 

EPA also conducted a separate analysis of the total benefits over the model year 

lifetimes of the 2012 through 2016 model year vehicles. In contrast to the calendar year 

analysis, the model year lifetime analysis shows the lifetime impacts of the program on each 

of these MY fleets over the course of its lifetime. Full details of the inputs to this analysis can 

be found in DRIA chapter 5. The societal benefits of the full life of each of the five model 

years from 2012 through 2016 are shown in Table 8-14 and Table 8-15 at both a 3 percent and 

a 7 percent discount rate, respectively. The net benefits are shown in Table 8-16 and Table 

8-17 for both a 3 percent and a 7 percent discount rate, respectively. Note that the quantified 

annual benefits shown in Table 8-14 and Table 8-15include fuel savings as a positive benefit. 

As such, the quantified annual costs as shown in Table 8-16 and Table 8-17 do not include 

fuel savings since those are included as benefits. Also note that Table 8-14 through Table 

8-17 include the benefits of reduced CO2 emissions—and consequently the total benefits—for 

each of five interim SCC values considered by EPA. As noted above, there is a very high 
Other Economic and Social Impacts 

8-23 

probability (very likely according to the IPCC) that the benefit estimates from GHG 

reductions are underestimates because, in part, models used to calculate SCC values do not 

include information about impacts that have not been quantified. 

Table 8-14 Estimated Societal Benefits Associated with the Proposed Light-Duty Vehicle GHG Program, 

Model Year Analysis (Millions of 2007 dollars; 3% Discount Rate) 

MONETIZED VALUES 2012MY 2013MY 2014MY 2015MY 2016MY SUM 

Cost of Noise, Accident, 

Congestion ($) -$900 -$1,400 -$1,900 -$2,800 -$3,900 -$11,000 

Pretax Fuel Savings ($) $15,600 $24,400 $34,800 $49,800 $68,500 $193,300 

Energy Security ($) (price 

shock) $400 $600 $900 $1,200 $1,600 $4,700 

Change in no. of Refueling 

(#) 500 700 1,000 1,300 1,800 5,300 

Change in Refueling Time 

(hours) 0 100 100 100 200 400 

Value of Reduced Refueling 

time ($) $900 $1,400 $1,900 $2,700 $3,700 $10,500 

Value of Additional Driving 

($) $2,000 $3,000 $4,100 $5,700 $7,900 $22,700 

Value of PM2.5 related Health 

Impacts ($)a,b,c $600 $900 $1,200 $1,700 $2,200 $6,600 

Social Cost of Carbon (SCC) at each assumed SCC value

SCC 5% $500 $700 $1,000 $1,400 $1,900 $5,600 

SCC 5% Newell-Pizer $1,000 $1,500 $2,000 $2,900 $3,800 $11,000 

SCC from 3% and 5% $1,800 $2,800 $3,900 $5,400 $7,200 $21,000 

SCC 3% $3,200 $4,800 $6,700 $9,400 $13,000 $37,000 

SCC 3% Newell-Pizer $5,300 $8,100 $11,000 $16,000 $21,000 $61,000 

Total Benefits at each assumed SCC value

SCC 5% $19,100 $29,600 $42,000 $59,700 $81,900 $232,400 

SCC 5% Newell-Pizer $19,600 $30,400 $43,000 $61,200 $83,800 $237,800 

SCC from 3% and 5% $20,400 $31,700 $44,900 $63,700 $87,200 $247,800 

SCC 3% $21,800 $33,700 $47,700 $67,700 $93,000 $263,800 

SCC 3% Newell-Pizer $23,900 $37,000 $52,000 $74,300 $101,000 $287,800 a Note that the co-pollutant impacts associated with the standards presented here do not include the full complement of 

endpoints that, if quantified and monetized, would change the total monetized estimate of rule-related impacts. Instead, the 

co-pollutant benefits are based on benefit-per-ton values that reflect only human health impacts associated with reductions in 

PM2.5 exposure. Ideally, human health and environmental benefits would be based on changes in ambient PM2.5 and ozone 

as determined by full-scale air quality modeling. However, we were unable to conduct a full-scale air quality modeling 

analysis in time for the proposal. We intend to more fully capture the co-pollutant benefits for the analysis of the final 

standards.

b The PM2.5-related benefits (derived from benefit-per-ton values) presented in this table are based on an estimate of 

premature mortality derived from the ACS study (Pope et al., 2002). If the benefit-per-ton estimates were based on the Six 

Cities study (Laden et al., 2006), the values would be approximately 145% (nearly two-and-a-half times) larger. c The PM2.5-related benefits (derived from benefit-per-ton values) presented in this table assume a 3% discount rate in the 

valuation of premature mortality to account for a twenty-year segmented cessation lag. If a 7% discount rate had been used, 

the values would be approximately 9% lower. 
Draft Regulatory Impact Analysis 

8-24 

Table 8-15. Estimated Societal Benefits Associated with the Proposed Light-Duty Vehicle GHG Program, 

Model Year Analysis (Millions of 2007 dollars; 7% Discount Rate) 

MONETIZED VALUES 2012MY 2013MY 2014MY 2015MY 2016MY SUM 

Cost of Noise, Accident, 

Congestion ($) -$700 -$1,100 -$1,500 -$2,200 -$3,100 -$8,700 

Pretax Fuel Savings ($) $12,100 $19,000 $27,200 $39,000 $53,700 $150,900 

Energy Security ($) (price 

shock) $300 $500 $700 $900 $1,300 $3,700 

Change in no. of Refueling (#) 400 500 800 1,100 1,500 4,200 

Change in Refueling Time 

(hours) 0 0 100 100 100 300 

Value of Reduced Refueling 

time ($) $700 $1,100 $1,500 $2,100 $2,900 $8,300 

Value of Additional Driving 

($) $1,500 $2,400 $3,200 $4,500 $6,300 $18,000 

Value of PM2.5 related Health 

Impacts ($)a,b,c $500 $700 $1,000 $1,300 $1,800 $5,300 

Social Cost of Carbon (SCC) at each assumed SCC value

SCC 5% $400 $500 $700 $1,000 $1,300 $3,900 

SCC 5% Newell-Pizer $700 $1,100 $1,500 $2,000 $2,500 $7,700 

SCC from 3% and 5% $1,400 $2,100 $2,800 $3,700 $4,800 $15,000 

SCC 3% $2,400 $3,600 $4,800 $6,500 $8,300 $26,000 

SCC 3% Newell-Pizer $4,000 $6,000 $8,000 $11,000 $14,000 $43,000 

Total Benefits at each assumed SCC value

SCC 5% $14,800 $23,100 $32,800 $46,600 $64,200 $181,400 

SCC 5% Newell-Pizer $15,100 $23,700 $33,600 $47,600 $65,400 $185,200 

SCC from 3% and 5% $15,800 $24,700 $34,900 $49,300 $67,700 $192,500 

SCC 3% $16,800 $26,200 $36,900 $52,100 $71,200 $203,500 

SCC 3% Newell-Pizer $18,400 $28,600 $40,100 $56,600 $76,900 $220,500 a Note that the co-pollutant impacts associated with the standards presented here do not include the full complement of 

endpoints that, if quantified and monetized, would change the total monetized estimate of rule-related impacts. Instead, the 

co-pollutant benefits are based on benefit-per-ton values that reflect only human health impacts associated with reductions in 

PM2.5 exposure. Ideally, human health and environmental benefits would be based on changes in ambient PM2.5 and ozone 

as determined by full-scale air quality modeling. However, we were unable to conduct a full-scale air quality modeling 

analysis in time for the proposal. We intend to more fully capture the co-pollutant benefits for the analysis of the final 

standards.

b The PM2.5-related benefits (derived from benefit-per-ton values) presented in this table are based on an estimate of 

premature mortality derived from the ACS study (Pope et al., 2002). If the benefit-per-ton estimates were based on the Six 

Cities study (Laden et al., 2006), the values would be approximately 145% (nearly two-and-a-half times) larger. c The PM2.5-related benefits (derived from benefit-per-ton values) presented in this table assume a 3% discount rate in the 

valuation of premature mortality to account for a twenty-year segmented cessation lag. If a 7% discount rate had been used, 

the values would be approximately 9% lower. 
Other Economic and Social Impacts 

8-25 

Table 8-16. Quantified Net Benefits Associated with the Proposed Light-Duty Vehicle GHG Program, 

Model Year Analysisa

 (Millions of 2007 dollars; 3% Discount Rate) 

2012MY 2013MY 2014MY 2015MY 2016MY SUM 

Quantified Annual Costs 

(excluding fuel savings) $5,400 $8,400 $10,900 $13,900 $17,500 $56,100 

Quantified Annual Benefits at each assumed SCC value 

SCC 5% $19,100 $29,600 $42,000 $59,700 $81,900 $232,400 

SCC 5% Newell-Pizer $19,600 $30,400 $43,000 $61,200 $83,800 $237,800 

SCC from 3% and 5% $20,400 $31,700 $44,900 $63,700 $87,200 $247,800 

SCC 3% $21,800 $33,700 $47,700 $67,700 $93,000 $263,800 

SCC 3% Newell-Pizer $23,900 $37,000 $52,000 $74,300 $101,000 $287,800 

Quantified Net Benefits at each assumed SCC value 

SCC 5% $13,700 $21,200 $31,100 $45,800 $64,400 $176,300 

SCC 5% Newell-Pizer $14,200 $22,000 $32,100 $47,300 $66,300 $181,700 

SCC from 3% and 5% $15,000 $23,300 $34,000 $49,800 $69,700 $191,700 

SCC 3% $16,400 $25,300 $36,800 $53,800 $75,500 $207,700 

SCC 3% Newell-Pizer $18,500 $28,600 $41,100 $60,400 $83,500 $231,700 a Note that the co-pollutant impacts associated with the standards presented here do not include the full 

complement of endpoints that, if quantified and monetized, would change the total monetized estimate of rulerelated impacts. Instead, the co-pollutant benefits are based on benefit-per-ton values that reflect only human 

health impacts associated with reductions in PM2.5 exposure. Ideally, human health and environmental benefits 

would be based on changes in ambient PM2.5 and ozone as determined by full-scale air quality modeling. 

However, we were unable to conduct a full-scale air quality modeling analysis in time for the proposal. We 

intend to more fully capture the co-pollutant benefits for the analysis of the final standards. 

Table 8-17. Quantified Net Benefits Associated with the Proposed Light-Duty Vehicle GHG Program, 

Model Year Analysisa

 (Millions of 2007 dollars; 7% Discount Rate) 

2012MY 2013MY 2014MY 2015MY 2016MY SUM 

Quantified Annual Costs 

(excluding fuel savings) $5,400 $8,400 $10,900 $13,900 $17,500 $56,100 

Quantified Annual Benefits at each assumed SCC value 

SCC 5% $14,800 $23,100 $32,800 $46,600 $64,200 $181,400 

SCC 5% Newell-Pizer $15,100 $23,700 $33,600 $47,600 $65,400 $185,200 

SCC from 3% and 5% $15,800 $24,700 $34,900 $49,300 $67,700 $192,500 

SCC 3% $16,800 $26,200 $36,900 $52,100 $71,200 $203,500 

SCC 3% Newell-Pizer $18,400 $28,600 $40,100 $56,600 $76,900 $220,500 

Quantified Net Benefits at each assumed SCC value 

SCC 5% $9,400 $14,700 $21,900 $32,700 $46,700 $125,300 

SCC 5% Newell-Pizer $9,700 $15,300 $22,700 $33,700 $47,900 $129,100 

SCC from 3% and 5% $10,400 $16,300 $24,000 $35,400 $50,200 $136,400 

SCC 3% $11,400 $17,800 $26,000 $38,200 $53,700 $147,400 

SCC 3% Newell-Pizer $13,000 $20,200 $29,200 $42,700 $59,400 $164,400 a Note that the co-pollutant impacts associated with the standards presented here do not include the full 

complement of endpoints that, if quantified and monetized, would change the total monetized estimate of rulerelated impacts. Instead, the co-pollutant benefits are based on benefit-per-ton values that reflect only human 

health impacts associated with reductions in PM2.5 exposure. Ideally, human health and environmental benefits 

would be based on changes in ambient PM2.5 and ozone as determined by full-scale air quality modeling. 

However, we were unable to conduct a full-scale air quality modeling analysis in time for the proposal. We 

intend to more fully capture the co-pollutant benefits for the analysis of the final standards. 
Draft Regulatory Impact Analysis 

8-26 

References 

All references can be found in the EPA DOCKET: EPA-HQ-OAR-2009-0472.

 1

 See, for instance, Gron, Ann, and Deborah Swenson, 2000. “Cost Pass-Through in the U.S. Automobile 

Market,” Review of Economics and Statistics 82: 316-324. 

2

 Insurance Information Institute, 2008, “Average Expenditures for Auto Insurance By State, 2005-2006,” 

http://www.iii.org/media/facts/statsbyissue/auto/, accessed April 23, 2009. 

3

 U.S. Department of Energy, 2008, “Average Price of a New Car, 1970-2006,” 

http://www1.eere.energy.gov/vehiclesandfuels/facts/2008_fotw520.html, accessed April 23, 2009. 

4

 Solheim, Mark, 2006“State Car Tax Rankings,” 

http://www.kiplinger.com/features/archives/2006/04/cartax.html, accessed April 23, 2009. 

5

 U.S. Census Bureau, “Population, Population change and estimated components of population change: April 1, 

2000 to July 1, 2008” (NST-EST2008-alldata), http://www.census.gov/popest/states/states.html, accessed April 

23, 2009. 

6 http://auto-loan.interest.com, 8/24/09 at 9:20AM. 

7

 Consumer Reports, August 2008,“What That Car Really Costs to Own,” 

http://www.consumerreports.org/cro/cars/pricing/what-that-car-really-costs-to-own-4-08/overview/what-thatcar-really-costs-to-own-ov.htm , accessed April 23, 2009. 

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 Kleit A.N., 1990, “The Effect of Annual Changes in Automobile Fuel Economy Standards,” Journal of 

Regulatory Economics 2: 151-172; McCarthy, Patrick S., 1996. “Market Price and Income Elasticities of New 

Vehicle Demands.” Review of Economics and Statistics 78: 543-547; Goldberg, Pinelopi K., 1998. “The Effects 

of the Corporate Average Fuel Efficiency Standards in the US,” Journal of Industrial Economics 46(1): 1-33; 

Greene, David L., “Feebates, Footprints and Highway Safety,” Transportation Research Part D 14 (2009): 375-

384. 

9

 Goldberg, Pinelopi Koujianou, “Product Differentiation and Oligopoly in International Markets: The Case of 

the U.S. Automobile Industry,” Econometrica 63(4) (July 1995): 891-951; Goldberg, Pinelopi Koujianou, “The 

Effects of the Corporate Average Fuel Efficiency Standards in the US,” Journal of Industrial Economics 46(1) 

(March 1998): 1-33. 

10 Greene, David L., K.G. Duleep, Doug Elliott, and Sanjana Ahmad, “A Fuel Economy Regulatory Analysis 

Model (FERAM) For the Energy Information Administration,” prepared by the Oak Ridge National Laboratory 

for the U.S. Department of Energy under contract No. DE-AC0500OR22725, 2005; Greene, David L., Philip D. 

Patterson, Margaret Singh, and Jia Li, “Feebates, Rebates, and Gas-Guzzler Taxes: A Study of Incentives for 

Increased Fuel Economy,” Energy Policy 33 (2005): 757-775. 

11 McManus, Walter M., “Can Proactive Fuel Economy Strategies Help Automakers Mitigate Fuel-Price Risks?” 

University of Michigan Transportation Research Institute, September 14, 2006. 

12 Berry, Steven, James Levinsohn, and Ariel Pakes, “Automobile Prices in Market Equilibrium,” Econometrica

63(4) (July 1995): 841-940; Berry, Steven, James Levinsohn, and Ariel Pakes, “Differentiated Products Demand 

Systems from a Combination of Micro and Macro Data: The New Car Market,” Journal of Political Economy

112(1) (2004): 68-105. 
Other Economic and Social Impacts 

8-27 

 13 Bento, Antonio M., Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen, and Roger H. von Haefen, 

“Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-Market Study,” 

American Economic Review 95(2) (May 2005): 282-287. 

14 Train, Kenneth E., and Clifford Winston, “Vehicle Choice Behavior and the Declining Market Share of U.S. 

Automakers,” International Economic Review 48(4) (November 2007): 1469-1496. 

15 Kleit, Andrew N., “Impacts of Long-Range Increases in the Fuel Economy (CAFE) Standard,” Economic 

Inquiry 42(2) (April 2004): 279-294. 

16 Austin, David, and Terry Dinan, “Clearing the Air: The Costs and Consequences of Higher CAFE Standards 

and Increased Gasoline Taxes,” Journal of Environmental Economics and Management 50 (2005): 562-582. 

17 E.g., Bento, Antonio M., Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen, and Roger H. von Haefen, 

“Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-Market Study,” 

American Economic Review 95(2) (May 2005): 282-287; Train, Kenneth E., and Clifford Winston, “Vehicle 

Choice Behavior and the Declining Market Share of U.S. Automakers,” International Economic Review 48(4) 

(November 2007): 1469-1496. 

18 E.g., Berry, Steven, James Levinsohn, and Ariel Pakes, “Automobile Prices in Market Equilibrium,” 

Econometrica 63(4) (July 1995): 841-940. 

19 Greene, David L., K.G. Duleep, Doug Elliott, and Sanjana Ahmad, “A Fuel Economy Regulatory Analysis 

Model (FERAM) For the Energy Information Administration,” prepared by the Oak Ridge National Laboratory 

for the U.S. Department of Energy under contract No. DE-AC0500OR22725, 2005. 

20 NERA Economic Consulting, “Evaluation of NHTSA’s Benefit-Cost Analysis of 2011-2015 CAFE 

Standards,” 2008, available at 

http://www.heartland.org/policybot/results/23495/Evaluation_of_NHTSAs_BenefitCost_Analysis_Of_20112015

_CAFE_Standards.html. 

21 E.g., Train, Kenneth E., and Clifford Winston, “Vehicle Choice Behavior and the Declining Market Share of 

U.S. Automakers,” International Economic Review 48(4) (November 2007): 1469-1496. 

22 E.g., Berry, Steven, James Levinsohn, and Ariel Pakes, “Automobile Prices in Market Equilibrium,” 

Econometrica 63(4) (July 1995): 841-940. 

23 E.g., Bento, Antonio M., Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen, and Roger H. von Haefen, 

“Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-Market Study,” 

American Economic Review 95(2) (May 2005): 282-287. 

24 Bento, Antonio M., Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen, and Roger H. von Haefen, 

“Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-Market Study,” 

American Economic Review 95(2) (May 2005): 282-287; Feng, Yi, Don Fullerton, and Li Gan, “Vehicle 

Choices, Miles Driven and Pollution Policies,” National Bureau of Economic Analysis Working Paper 11553, 

available at http://econweb.tamu.edu/gan/w11553.pdf , accessed 5/12/09. 

25 NERA Economic Consulting, “Appendix B: New Vehicle Market Model,” “Impacts of the California 

Greenhouse Gas Emission Standards on Motor Vehicle Sales,” comments submitted to the U.S. Environmental 

Protection Agency at Regulations.gov, document number EPA-HQ-OAR-2006-0173-9053.1. 

26 Berry, Steven, James Levinsohn, and Ariel Pakes, “Automobile Prices in Market Equilibrium,” Econometrica

63(4) (July 1995): 841-940. 
Draft Regulatory Impact Analysis 

8-28 

 27 Goldberg, Pinelopi Koujianou, “Product Differentiation and Oligopoly in International Markets: The Case of 

the U.S. Automobile Industry,” Econometrica 63(4) (July 1995): 891-951. 

28 Brownstone, David, and Kenneth Train, “Forecasting New Product Penetration with Flexible Substitution 

Patterns,” Journal of Econometrics 89 (1999): 109-129; Brownstone, David, David S. Bunch, and Kenneth 

Train, “Joint Mixed Logit Models of Stated and Revealed Preferences for Alternative-Fuel Vehicles,” 

Transportation Research Part B 34 (2000): 315-338; Greene David L., “TAFV Alternative Fuels and Vehicles 

Choice Model Documentation,” prepared by the Oak Ridge National Laboratory for the U.S. Department of 

Energy, July 2001; Greene, David L., K. G. Duleep, and Walter McManus, “Future Potential of Hybrid and 

Diesel Powertrains in the U.S. Light-Duty Vehicle Market,” prepared by the Oak Ridge National Laboratory for 

the U.S. Department of Energy, August 2004. 

29 Petrin, Amil, “Quantifying the Benefits of New Products: The Case of the Minivan,” Journal of Political 

Economy 110 (2002): 705-729; Berry, Steven, James Levinsohn, and Ariel Pakes, “Differentiated Products 

Demand Systems from a Combination of Micro and Macro Data: The New Car Market,” Journal of Political 

Economy 112 (2004): 68-105. 

30 Train, Kenneth E., and Clifford Winston, “Vehicle Choice Behavior and the Declining Market Share of U.S. 

Automakers,” International Economic Review 48 (November 2007): 1469-1496. 

31 Bento, Antonio M., Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen, and Roger H. von Haefen, 

“Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-Market Study,” 

American Economic Review 95(2) (May 2005): 282-287; Feng, Yi, Don Fullerton, and Li Gan, “Vehicle 

Choices, Miles Driven and Pollution Policies,” National Bureau of Economic Analysis Working Paper 11553, 

available at http://econweb.tamu.edu/gan/w11553.pdf , accessed 5/12/09. 

32 Greene, David L., Philip D. Patterson, Margaret Singh, and Jia Li, “Feebates, Rebates, and Gas-Guzzler 

Taxes: A Study of Incentives for Increased Fuel Economy,” Energy Policy 33 (2005): 757-775; Feng, Yi, Don 

Fullerton, and Li Gan, “Vehicle Choices, Miles Driven and Pollution Policies,” National Bureau of Economic 

Analysis Working Paper 11553, available at http://econweb.tamu.edu/gan/w11553.pdf , accessed 5/12/09; 

Greene, David L., “Feebates, Footprints and Highway Safety,” Transportation Research Part D (2009) (in press). 

33 E.g., Austin, David, and Terry Dinan, “Clearing the Air: The Costs and Consequences of Higher CAFE 

Standards and Increased Gasoline Taxes,” Journal of Environmental Economics and Management 50 (2005): 

562-582. 

34 Turrentine, Thomas S., and Kenneth S. Kurani, “Car Buyers and Fuel Economy?” Energy Policy 35 (2007): 

1213-1223. 

35 E.g., Espey, Molly, and Santosh Nair, 2005. “Automobile Fuel Economy: What Is It Worth?” Contemporary 

Economic Policy 23: 317-323. 

36 Larrick, Richard P., and Jack B. Soll, 2008. “The MPG Illusion,” Science 320(5883): 1593-1594. 

37 E.g., Goldberg, Pinelopi Koujianou, “Product Differentiation and Oligopoly in International Markets: The 

Case of the U.S. Automobile Industry,” Econometrica 63(4) (July 1995): 891-951. 

38 E.g., Berry, Steven, James Levinsohn, and Ariel Pakes, “Automobile Prices in Market Equilibrium,” 

Econometrica 63(4) (July 1995): 841-940. 

39 Busse, Meghan, Christopher R. Knittel, and Florian Zettelmeyer, 2009. “Pain at the Pump: How Gasoline 

Prices Affect Automobile Purchasing in New and Used Markets,” working paper, 

http://www.econ.ucdavis.edu/faculty/knittel/papers/gaspaper_latest.pdf (accessed 6/16/09). 
Other Economic and Social Impacts 

8-29 

 40 Greene, David L., and Jin-Tan Liu, 1988. “Automotive Fuel Economy Improvements and Consumers’ 

Surplus,” Transportation Research Part A 22A (3): 203-218. 

41 Goldberg, Pinelopi Koujianou, “Product Differentiation and Oligopoly in International Markets: The Case of 

the U.S. Automobile Industry,” Econometrica 63(4) (July 1995): 891-951; Berry, Steven, James Levinsohn, and 

Ariel Pakes, “Automobile Prices in Market Equilibrium,” Econometrica 63(4) (July 1995): 841-940. 

42 Gramlich, Jacob, “Gas Prices and Endogenous Product Selection in the U.S. Automobile Industry,” 

http://www.econ.yale.edu/seminars/apmicro/am08/gramlich-081216.pdf , accessed 5/11/09. 

43 Gramlich, Jacob, “Gas Prices and Endogenous Product Selection in the U.S. Automobile Industry,” 

http://www.econ.yale.edu/seminars/apmicro/am08/gramlich-081216.pdf , accessed 5/11/09. 

44 Espey, Molly, and Santosh Nair, 2005. “Automobile Fuel Economy: What Is It Worth?” Contemporary 

Economic Policy 23: 317-323. 

45 McManus, Walter, “Can Proactive Fuel Economy Strategies Help Automakers Mitigate Fuel-Price Risks?” 

Ann Arbor, MI: University of Michigan Transportation Research Institute; Munich Personal RePEc Archive 

Paper No. 3460, September 14, 2006; http://mpra.ub.uni-muenchen.de/3460/1/MPRA_paper_3460.pdf, accessed 

6/16/09. 

46 Gramlich, Jacob, “Gas Prices and Endogenous Product Selection in the U.S. Automobile Industry,” 

http://www.econ.yale.edu/seminars/apmicro/am08/gramlich-081216.pdf , accessed 5/11/09. 

47 Gramlich, Jacob, “Gas Prices and Endogenous Product Selection in the U.S. Automobile Industry,” 

http://www.econ.yale.edu/seminars/apmicro/am08/gramlich-081216.pdf , accessed 5/11/09; McManus, Walter, 

2007. “The Impact of Attribute-Based Corporate Average Fuel Economy (CAFE) Standards: Preliminary 

Results.” Ann Arbor, MI: University of Michigan Transportation Research Institute, Report No. UMTRI-2007-

31. 

48 For instance, Kleit, Andrew N., “Impacts of Long-Range Increases in the Fuel Economy (CAFE) Standard,” 

Economic Inquiry 42(2) (April 2004): 279-294; Austin, David, and Terry Dinan, “Clearing the Air: The Costs 

and Consequences of Higher CAFE Standards and Increased Gasoline Taxes,” Journal of Environmental 

Economics and Management 50 (2005): 562-582; Klier, Thomas, and Joshua Linn, 2008. “New Vehicle 

Characteristics and the Cost of the Corporate Average Fuel Economy Standard,” Federal Reserve Bank of 

Chicago WP 2008-13, at http://www.chicagofed.org/publications/workingpapers/wp2008_13.pdf (accessed 

5/6/09); Jacobsen, Mark, 2008. “Evaluating U.S. Fuel Economy Standards in a Model with Producer and 

Household Heterogeneity,” working paper, at http://econ.ucsd.edu/~m3jacobs/Jacobsen_CAFE.pdf (accessed 

5/6/09). 

49 Austin, David, and Terry Dinan, “Clearing the Air: The Costs and Consequences of Higher CAFE Standards 

and Increased Gasoline Taxes,” Journal of Environmental Economics and Management 50 (2005): 562-582. 

50 IEA. 2007. “Mind the Gap: Quantifying Principal-Agent Problems in Energy Efficiency.” Paris, France: 

International Energy Agency; Jaffe, Adam B., Richard G. Newell, and Robert N. Stavins (2001). "Energy 

Efficient Technologies and Climate Change Policies: Issues and Evidence." In Climate Change Economics and 

Policy, Toman, Michael A., ed., Washington, D.C.: Resources for the Future. p.171-181; Metcalf, Gilbert E., and 

Kevin A. Hassett (1999). "Measuring the Energy Savings From Home Improvement Investments: Evidence 

From Monthly Billing Data." The Review of Economics and Statistics 81(3): 516-528; Tietenberg, T. (2009). 

“Reflections – Energy Efficiency Policy: Pipe Dream or Pipeline to the Future?” Review of Environmental 

Economics and Policy. Vol.3, 2: 304-320. 
Draft Regulatory Impact Analysis 

8-30 

 51 Welch, David. “CAFE: A Prize for Making Gas-Guzzlers?” Business Week April 16, 2009, 

http://www.businessweek.com/magazine/content/09_17/b4128048030307.htm?chan=magazine+channel_what's

+next , accessed 7/7/09. 

52 Berry, Steven, James Levinsohn, and Ariel Pakes (July 1995). “Automobile Prices in Market Equilibrium,” 

Econometrica 63(4): 841-940. 

53 Greene, David L., Philip D. Patterson, Margaret Singh, and Jia Li, “Feebates, Rebates, and Gas-Guzzler 

Taxes: A Study of Incentives for Increased Fuel Economy,” Energy Policy 33 (2005): 757-775. 

54 Peer Review Report Summary: Estimating the Energy Security Benefits of Reduced U.S. Oil Imports, ICF, 

Inc., September 2007. 

55 Estimated reductions in imports of finished petroleum products and crude oil are 95% of 108 MMB in 2015, 

353MMB in 2020, 637MMB in 2030,and 740MMB in 2040. 

56 Preliminary Regulatory Impacts Analysis, April 2008. Based on a detailed analysis of differences in fuel 

consumption, petroleum imports, and imports of refined petroleum products among the Reference Case, High 

Economic Growth, and Low Economic Growth Scenarios presented in the Energy Information Administration’s 

Annual Energy Outlook 2007, NHTSA estimated that approximately 50 percent of the reduction in fuel 

consumption is likely to be reflected in reduced U.S. imports of refined fuel, while the remaining 50 percent 

would be expected to be reflected in reduced domestic fuel refining. Of this latter figure, 90 percent is 

anticipated to reduce U.S. imports of crude petroleum for use as a refinery feedstock, while the remaining 10 

percent is expected to reduce U.S. domestic production of crude petroleum. Thus on balance, each gallon of fuel 

saved is anticipated to reduc total U.S. imports of crude petroleum or refined fuel by 0.95 gallons.. 

57 See http://ostpxweb.dot.gov/policy/Data/VOT97guid.pdf and 

http://ostpxweb.dot.gov/policy/Data/VOTrevision1_2-11-03.pdf

58 California Environmental Protection Agency, Air Resources Board. Draft Assessment of the Real-World 

Impacts of Commingling California Phase 3 Reformulated Gasoline. August 2003 

59 The 19.3 gallon average tank size is from EPA calculations conducted on the Volpe Model Market Data file 

used in NHTSA’s Model Year 2011 CAFE Standards Final Rule. 

60 These benefits are included in the value of fuel savings reported in Tables VIII-5 through VIII-9. 

61 These estimates were developed by FHWA for use in its 1997 Federal Highway Cost Allocation Study; see

http://www.fhwa.dot.gov/policy/hcas/final/index.htm (last accessed July 29, 2009). 

62 See Federal Highway Administration, 1997 Federal Highway Cost Allocation Study, 

http://www.fhwa.dot.gov/policy/hcas/final/index.htm, Tables V-22, V-23, and V-24 (last accessed July 27, 

2009). 

63 The Federal Highway Administration’s estimates of these costs agree closely with some other recent estimates. 

For example, recent published research conducted by Resources for the Future (RFF) estimates marginal 

congestion and external accident costs for increased light-duty vehicle use in the U.S. to be 3.5 and 3.0 cents per 

vehicle-mile in year-2002 dollars. See Ian W.H. Parry and Kenneth A. Small, “Does Britain or the U.S. Have 

the Right Gasoline Tax?” Discussion Paper 02-12, Resources for the Future, 19 and Table 1 (March 2002). 

Available at http://www.rff.org/rff/Documents/RFF-DP-02-12.pdf (last accessed July 27, 2009). 
Small Business Flexibility Analysis 

9-1 

CHAPTER 9:Small Business Flexibility Analysis 

The Regulatory Flexibility Act, as amended by the Small Business Regulatory 

Enforcement Fairness Act of 1996 (SBREFA), generally requires an agency to prepare a 

regulatory flexibility analysis of any rule subject to notice-and-comment rulemaking 

requirements under the Administrative Procedure Act or any other statute, unless the 

agency certifies that the rule will not have a significant economic impact on a substantial 

number of small entities. As a part of this analysis, an agency is directed to convene a 

Small Business Advocacy Review Panel (SBAR Panel or ‘the Panel’). During the Panel 

process, we would gather information and recommendations from Small Entity 

Representatives (SERs) on how to reduce the impact of the rule on small entities. 

The following provides an overview of small entities in the vehicle market. Small 

entities include small businesses, small organizations, and small governmental 

jurisdictions. For the purposes of assessing the impacts of the proposed rule on small 

entities, a small entity is defined as: (1) a small business that meets the definition for 

business based on the Small Business Administration’s (SBA) size standards (see Table 

9-1); (2) a small governmental jurisdiction that is a government of a city, county, town, 

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

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

operated and is not dominant in its field. Table 9-1 provides an overview of the primary 

SBA small business categories potentially affected by this proposed regulation. 

Table 9-1: Primary Vehicle SBA Small Business Categories

 NAICSa

 Codes Defined by SBA As a 

small business if less than 

or equal to :b

Light-duty vehicle manufacturers 336111 1,000 employees. 

Vehicle importers 81111, 811112 $7 million annual sales. 

Alternative fuel vehicle converters 811198 $7 million annual sales. 

a. North American Industry Classification System 

b. According to SBA’s regulations (13 CFR 121), businesses with no more than the listed 

number of employees or dollars in annual receipts are considered “small entities” for 

RFA purposes. 

We compiled a list of vehicle manufacturers, independent commercial importers 

(ICIs), and alternative fuel converters that would be potentially affected by the proposed 

rule from our 2008 model year certification databases. These companies are already 

certifying their vehicles for compliance with applicable EPA emissions standards (e.g., 

Tier 2). We then identified companies that appear to meet the definition of small 

business provided in the table above. We were able to identify companies based on 

certification information and previous rulemakings where we conducted Regulatory 

Flexibility Analyses. 

Based on a preliminary assessment, EPA has identified a total of about 47 vehicle 

entities, 33 of which are vehicle manufacturers. Of a total of 33 manufacturers, 2 
Draft Regulatory Impact Analysis 

9-2 

manufacturers fit the SBA definition of a small entity. These businesses produce vehicles 

for small niche markets, and all of these entities manufacture limited production, high 

performance cars. Independent commercial importers (ICIs) are companies that hold a 

Certificate (or Certificates) of Conformity permitting them to import nonconforming 

vehicles and to modify these vehicles to meet U.S. emission standards. ICIs are not 

required to meet the emission standards in effect when the vehicle is modified, but 

instead they must meet the emission standards in effect when the vehicle was originally 

produced (with an annual production cap of a total of 50 light-duty vehicles and trucks). 

There are currently eight ICIs, all of which are small entities. Alternative fuel vehicle 

converters are businesses that convert gasoline or diesel vehicles to operate on alternative 

fuel (e.g., compressed natural gas), and converters must seek a certificate for all of their 

vehicle models. Model year 1993 and newer vehicles that are converted are required to 

meet the standards applicable at the time the vehicle was originally certified. Converters 

serve a small niche market, and these businesses primarily convert vehicles to operate on 

compressed natural gas (CNG) and liquefied petroleum gas (LPG), on a dedicated or dual 

fuel basis. We identified six alternative fuel converters in the light-duty vehicle market, 

and three of these would qualify as small entities under SBA’s definition. Together, we 

estimate that small entities comprise less than 0.1 percent of total annual vehicle sales 

and deferring standards for them will have a negligible impact on the GHG emissions 

reductions from the proposed standards. 

EPA has not conducted a Regulatory Flexibility Analysis or a SBREFA SBAR 

Panel for the proposed rule because we are proposing to certify that the rule would not 

have a significant economic impact on a substantial number of small entities. EPA is 

proposing to defer standards for manufacturers meeting SBA’s definition of small 

business as described in 13 CFR 121.201. EPA would instead consider appropriate GHG 

standards for these entities as part of a future regulatory action. This includes small 

entities in three distinct categories of businesses for light-duty vehicles: small volume 

manufacturers, independent commercial importers (ICIs), and alternative fuel vehicle 

converters. EPA has identified about 13 entities that fit the Small Business 

Administration (SBA) criterion of a small business. EPA estimates that these small 

entities comprise less than 0.1 percent of the total light-duty vehicle sales in the U.S., and 

therefore the proposed deferment will have a negligible impact on the GHG emissions 

reductions from the proposed standards. 

To ensure that EPA is aware of which companies would be deferred, EPA is 

proposing that such entities submit a declaration to EPA containing a detailed written 

description of how that manufacturer qualifies as a small entity under the provisions of 13 

CFR 121.201. Small entities are currently covered by a number of EPA motor vehicle 

emission regulations, and they routinely submit information and data on an annual basis 

as part of their compliance responsibilities. Because such entities are not automatically 

exempted from other EPA regulations for light-duty vehicles and light-duty trucks, absent 

such a declaration, EPA would assume that the entity was subject to the greenhouse gas 

control requirements in this GHG proposal. The declaration would need to be submitted 

at time of vehicle emissions certification under the EPA Tier 2 program. EPA expects 

that the additional paperwork burden associated with completing and submitting a small 
Small Business Flexibility Analysis 

9-3 

entity declaration to gain deferral from the proposed GHG standards would be negligible 

and easily done in the context of other routine submittals to EPA. However, EPA has 

accounted for this cost with a nominal estimate included in the Information Collection 

Request completed under the Paperwork Reduction Act. Additional information can be 

found in the Paperwork Reduction Act discussion in section III.I.2. Based on this, EPA 

is proposing to certify that the rule would not have a significant economic impact on a 

substantial number of small entities.