This final rule reforms the structure of the Corporate Average Fuel Economy (CAFE) program for light trucks and establishes higher CAFE standards for model year (MY) 2008-2011 light trucks. Manufacturers may comply with CAFE standards established under the reformed structure (Reformed CAFE) or with standards established in the traditional way (Unreformed CAFE) during a transition period of MYs 2008-2010. In MY 2011, all manufacturers will be required to comply with a Reformed CAFE standard. Under Reformed CAFE, fuel economy standards are restructured so that they are based on a measure of vehicle size called "footprint," the product of multiplying a vehicle's wheelbase by its track width. A target level of fuel economy is established for each increment in footprint. Smaller footprint light trucks have higher targets and larger ones, lower targets.