Average U.S. mpg edges up to 25.5 in May

The average fuel economy of light vehicles sold in the U.S. was up 0.3 mpg in May, according to the University of Michigan Transportation Research Institute.

“The improvement likely reflects the increased price of gasoline in May,” UMTRI researcher Michael Sivak said in a statement Wednesday.

The average window-sticker value of new cars, SUVs, vans and pickups purchased in the U.S. was 25.5 mpg in May, up from 25.2 in April.

May is the 16th consecutive month that average fuel economy has been at least 25 mpg. The average fuel economy of new vehicles has increased by 5.4 mpg since UMTRI researchers Sivak and Brandon Schoettle began keeping track in October 2007.

The average fuel economy for the first eight months of the 2015 model year -- October 2014 through May 2015 -- sits at 25.3 mpg. This is the same average recorded during the fist eight months of the 2014 model year.

Last month’s fuel economy average is still just below the record of 25.8 mpg set in August.

The institute also tracked the average monthly greenhouse gas emissions of each new-vehicle driver in the U.S. during March with its Eco-Driving Index. The EDI takes into account both the fuel used per distance driven and the amount of driving done in the month studied.

In March, the EDI remained flat at 0.82 for the third month in a row. Since the institute began keeping track in October 2007, greenhouse gas emissions of new-vehicle drivers are down 18 percent.