DETROIT — 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 5 mpg since 2004, according to an annual report released by the agency Wednesday. The EPA is predicting slower growth for this year, but officials still expect the industry to meet government standards that require the fleet to average 54.5 mpg by 2025.
The EPA, which bases its calculations on cars and trucks produced for sale in the U.S., is only predicting a 0.1 mpg increase from 2013 to 2014 as pickup truck and SUV production rises 2 percent.



