### 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY

2000 TRAVERWOOD DRIVE
ANN ARBOR, MI 48105

- 2498

OFFICE OF

AIR AND RADIATION



### Memorandum

From: Edward Nam, Director, Light Duty Vehicle an d Small Engine Center

, Assessment

and Standards Division

To: Docket EPA

- HQ

- OAR

- 2010

- 0799

Date: August 10, 2012 Subject: Comparison of the Calendar Year Analyses for the Greenhouse Gas Emissions

and Fuel Economy Programs for Model Year 2017

- 2025 Stan dards

This memorandum compares the benefits shown in the EPA’s and NHTSA’s respective analyses in the context of calendar years 2030, 2040 and 2050. 1 

### A comparison of the agencies’ analyses shows the EPA GHG standards are projected to produce additional greenhouse gas emission reductions and fuel savings in these years. These additional savings are due to several

differences between the GHG and CAFE standards, as discussed in P reamble Section I.C. 2 

### The most significant of these include:

The GHG standard s account for hydrofluorocarbon ( HFC ) emission reductions not required under CAFE. The HFC leakage control program will account for significant

additional GHG benefit s relative to the CAFE standards.

Under the EPA GHG program, there is no ability for a ma nufacturer to pay civil penalties in lieu of meeting the standard. Under EPCA, however, vehicle manufacturers are allowed to pay civil penalties as an alternative to compliance with applicable CAFE standards. NHTSA’s analysis explicitly (and properly) esti mates the level of voluntary civil penalty payment by individual manufacturers, which reduces NHTSA’s estimates
of both the costs and benefits of the CAFE standards. In contrast, as noted, the CAA does not allow for civil penalties in lieu of compliance wi th emission standards.

A number of smaller differences in the implementation of program flexibilities (flexible fueled vehicle credits during MY 2017

- MY 2019, intermediate volume manufacturer standards, different treatment of alternative fueled vehicles, e tc).

Modeling differences, as discussed in Preamble I.C. 3

1 Results are from preamble tables III

- 62, IV

- 67 and IV

- 68 in the Final Rulemaking 2017 and Later Model Year Light

- Duty Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Economy Standards

2 A similar discussion of the di fferences in the EPA and NHTSA statutory authorities and resulting modeling techniques is shown in the MYs 2012

- 2016 rule (75 FR at 25343).

3 As noted in preamble tables I

- 1 and I

- 2, NHTSA projects a fleet average shortfall of 2.3 MPG between the

achieved and the required fuel economy in MY 2025. Under NHTSA Environmental Impact Analysis approach A1, fuel economy levels are held constant after MY 2025, and this gap continues indefinitely. See Final EIS page 2

- 36 ( Docket No. NHTSA

- 2011

- 0056 ).

### 2 Table 1

- Comparison of Calendar Year B enefits 4

GHG reductions

GHG stds. (MMT CO2eq) CAFE stds.

(MMT CO2 ) Additional Benefit

from GHG stds. (%) Additional Benefit

from GHG stds. (MMT CO2eq)

2 030 271 224 17% 47

2040 455 349 23% 106

2050 569 416 27% 153

Fuel Savings (B. Gallons)

GHG stds. (B. Gallons) CAFE stds.

(B. Gallons) Additional Benefit

from GHG stds. (%) Additional Benefit

from GHG stds. (B. Gallons)

2030 23 21 9% 2

2040 39 32 1 8% 7

2050 49 39 20% 10

4 Results ar e from preamble tables III

- 62, IV

- 67 and IV

- 68