ANN ARBOR—Gas mileage of new vehicles sold in the U.S. dipped slightly in December, say researchers at the University of Michigan Transportation Research Institute.

The average fuel economy (window-sticker value) of new vehicles sold last month was 24.9 mpg—down 0.1 from November. For the year, new cars and light trucks sold in 2016 averaged 25.2 mpg—also down 0.1 mpg from the year before.

Overall, fuel economy is down 0.6 mpg from the peak of 25.5 mpg reached in August 2014, but still up by 4.8 mpg since October 2007—the first full month of monitoring by Michael Sivak and Brandon Schoettle.

In addition to average fuel economy, Sivak and Schoettle issued a monthly update of their national Eco-Driving Index, which estimates the average monthly emissions generated by an individual U.S. driver. The EDI takes into account both the fuel used per distance driven and the amount of driving—the latter relying on data that are published with a two-month lag.

During October, the EDI remained unchanged at 0.83 (the lower the value, the better) for the second straight month. The index currently shows emissions of greenhouse gases per driver of newly purchased vehicles are down 17 percent, overall, since October 2007—but 4 percentage points higher than the record low reached in November 2015.

More information:

• Fuel economy (with graph and table of current/recent mpg)
• Eco-Driving Index (with graph and table of current/recent values)
• Michael Sivak
• Brandon Schoettle

U-M Sustainability fosters a more sustainable world through collaborations across campus and beyond aimed at educating students, generating new knowledge, and minimizing our environmental footprint. Learn more at sustainability.umich.edu.