Associated Press: Gas mileage for new cars and trucks in the U.S. averaged a record 24.1 miles per gallon last year, but gains in fuel economy are slowing.
The Environmental Protection Agency says fuel economy last year rose one-half mile per gallon over the 2012 model year, mainly because automakers have improved gas engines and transmissions and added turbochargers to give smaller motors more power.
Although last year's gain fell short of the 1.2 mpg improvement from 2011 to 2012, fuel economy is up almost...