"This assessment examines the costs and benefits of improving the fuel economy of passenger cars and light trucks for model years (MY) 2011- 2015.  It includes a discussion of the technologies that can improve fuel economy, analysis of the potential impact on retail prices, safety, lifetime fuel savings and their value to consumers, and other societal benefits such as improved energy security and reduced emissions of pollutants and greenhouse gases.

"In the previous rulemaking, the agency reformed the corporate average fuel economy (CAFE) standards for light trucks with a size-based standard based on footprint2.  This rulemaking continues this approach for both passenger cars and light trucks.  A continuous mathematical function provides a separate fuel economy target for each footprint.  Different parameters for the continuous mathematical function are derived for each model year.  Individual manufacturers will be required to comply with a single fuel economy level that is based on the distribution of its production among the footprints of its vehicles in each particular model year.  Although the same reformed CAFE scheme is proposed for both passenger cars and light trucks, they are established with different continuous mathematical functions specific to their design capabilities.

"The agency is proposing the “Optimized (7%)” alternative.  In this alternative the agency uses a 7 percent discount rate to value benefits and sets the proposed mpg levels where marginal costs equal marginal benefits.  It is one of six alternatives examined in the analysis..."

"This document proposes substantial increases in the Corporate Average Fuel Economy (CAFE) standards for passenger cars and light trucks that would enhance energy security by improving fuel economy. Since the carbon dioxide (CO2) emitted from the tailpipes of new motor vehicles is the natural by-product of the combustion of fuel, the increased standards would also address climate change by reducing tailpipe emissions of CO2. Those emissions represent 97 percent of the total greenhouse gas emissions from motor vehicles. Implementation of the new standards would dramatically add to the billions of barrels of fuel already saved since the beginning of the CAFE program in 1975."

DOT Responses to NAS Questions about OMB's Proposed Risk Assessment Guidance