UPDATE: U.S. Fleet Fuel Economy at Record High

New cars and light trucks in the U.S. climbed to a record-high average of 24.9 mpg in the 2017 model year, according to the Environmental Protection Agency.

The average rose from 24.7 mpg in 2016 in spite of a huge market swing from cars to less efficient SUVs and pickup trucks.

Honda Motor Co. ranked best in corporate average fuel economy for 2017 at 29.4 mpg. Other top performers are Mazda (29.0 mpg), Hyundai (28.6 mpg) and Subaru (28.5 mpg).

The worst averages were posted by Ford and General Motors (each at 22.9 mpg) and Fiat Chrysler Automobiles (21.2 mpg). All three companies sell a high proportion of SUVs and pickup trucks, which lower their averages.

EPA says early data suggest that marketwide average fuel economy for the 2018 model year climbed to 25.4 mpg.

But the agency also cautions that 10 of the market’s largest 13 carmakers achieved their regulatory goals in 2017 only by using credits. Companies may apply credits saved from prior years when they surpassed their goals, or by buying them from other producers that did so.

The agency says the rising use of credits raises “legitimate concerns” about the auto industry’s ability to meet ever-rising fuel economy targets. The Trump administration, buttressed by an EPA analysis last spring, intends to freeze those goals after 2020.

Doing so would scrap emission rules set during the Obama era that would impose annual fuel efficiency gains of about 5% between 2020 and 2026 and lead to a fleet average target of 36 mpg.