Truck Boom Stalls U.S. Fuel Economy Gains

Surging truck sales in the U.S. left the country’s new-car fuel economy average stalled at 24.3 mpg in 2014, unchanged from the upwardly revised average for 2013, the Environmental Protection Agency reports.

The national average climbed 0.7 mpg from 2012 to 2013, when fuel prices were higher.

Last year, light trucks captured 52% of the U.S. market compared with 50% in 2013, according to Autodata Corp. Their share ballooned to 55% through the first 11 months of this year and reached nearly 59% in November.

Still, carmakers have increased their fuel economy average 26%, or by 5 mpg, over the past decade, EPA calculates. And since 2011, the companies have held greenhouse gas emissions from their vehicles to levels significantly below allowable limits.

EPA notes that carmakers earn credits by selling flex-fuel vehicles, electrics and hybrids. They also can buy credits from other carmakers whose vehicles exceed the annual targets, as 11 of the market’s 13 highest-volume producers did in 2014.

Honda, Nissan, Tesla and Toyota have sold credits to other companies over the past five years, the agency says. During the same period, Daimler, Ferrari and Fiat Chrysler Automobiles bought credits to avoid penalties.