In this Friday, July 29, 2011, photo, President Barack Obama walks down a ramp after delivering a speech at a gathering where he announced new fuel efficiency standards for cars and light trucks at the Washington Convention Center in Washington.The average gas mileage of new cars and trucks will have to nearly double by 2025 under regulations that were finalized Tuesday, Aug. 28, 2012, by the Obama administration. The new rules would require the fleet of new cars and trucks to average 54.5 miles per gallon in 13 years, up from 28.6 mpg at the end of last year. (AP Photo/Manuel Balce Ceneta)

Photo by: Manuel Balce Ceneta

In this Friday, July 29, 2011, photo, President Barack Obama walks down a ramp after delivering a speech at a gathering where he announced new fuel efficiency standards for cars and light trucks at the Washington Convention Center in Washington.The average gas mileage of new cars and trucks will have to nearly double by 2025 under regulations that were finalized Tuesday, Aug. 28, 2012, by the Obama administration. The new rules would require the fleet of new cars and trucks to average 54.5 miles per gallon in 13 years, up from 28.6 mpg at the end of last year. (AP Photo/Manuel Balce Ceneta)