In its monthly report, the University of Michigan Transportation Research Institute indicates that the average fuel economy for light vehicles increased to 25.4 mpg in May, up 0.2 mpg from April.

Overall, fuel economy ratings were down 0.4 mpg from a peak of 25.8 mpg in August 2014 but remain up 5.3 mpg from a low of 20.1 mpg recorded when the institute began monitoring in October 2007.

Michael Sivak, Director of Sustainable Worldwide Transportation at the university, indicates in the release that the improvement “likely reflects the increased price of gasoline in May, and the consequent increased interest in more fuel-efficient vehicles by buyers of all vehicle classes.”

The University of Michigan Eco-Driving Index (EDI) was .84 in March, up 0.03 from February 2016. The index estimates the average emissions of greenhouse gases generated by U.S. drivers on a monthly basis.

Overall, the EDI value for March was 16 percent lower than emissions reported compared to October 2007 but up 6 percent over record lows reached in August 2014 and August 2015.