The University of Michigan said last month the average "window sticker ratings" for fuel economy of vehicles in July was 24.8 miles per gallon.
The Energy Department said it was backing 38 different projects with a combined $45 million to improve fuel efficiency, lower transportation costs and cut down on greenhouse gas emissions.
Energy Secretary Ernest Moniz said Wednesday the research would eventually help save consumers money at the pump.
Motor group AAA reports U.S. consumers paid, on average, $3.58 for a gallon of regular unleaded gasoline Thursday, about 25 cents less than the same time last year. Refinery issues in the U.S. Midwest pushed gasoline prices above the $4 mark in some retail markets early this year.
Washington last year called for a fleet fuel economy of 54.5 mpg by 2025. Most of the projects targeted by the Energy Department's investment are for lightweight materials and advanced batteries.