ANN ARBOR (WWJ) – A new study from the University of Michigan says the fuel economy of new vehicles dropped last month.

WWJ Newsradio 950′s Gary Lundy reports that after two months of increases, the average fuel economy of all vehicles sold in the United States fell by a half mile per gallon.

Researchers at the U-M Transportation Research Institute are making the claim in a new study siting the  lower gas mileage in new cars.

The average fuel economy of cars, minivans, light trucks and SUV’s purchased in December was 22.2 mpg. That’s down from 22.7 mpg in November.

Meanwhile, the EPA and the National Highway Safety Administration will hold a hearing this week in Detroit, on the proposed 54.5 mile per gallon fuel economy standard.

Find more details on the U-M study here.