ANN ARBOR—Fuel economy of new vehicles sold in the U.S. backed off its record high last month, but average monthly emissions are now at an all-time low, say researchers at the University of Michigan Transportation Research Institute.

Average fuel economy (window-sticker values) of cars, light trucks, vans and SUVs purchased in April was 25.2 mpg, down 0.2 mpg from March, but still up 5.1 mpg from October 2007, the first full month of monitoring by UMTRI researchers Michael Sivak and Brandon Schoettle.

“This change likely reflects the increased proportion of light trucks among newly purchased vehicles,” Sivak said.

On the other hand, vehicle emissions from new vehicles are at a record mark, according to Sivak’s and Schoettle’s 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.

The EDI fell to 0.77 (the lower the value, the better) during February from a revised mark of 0.81 in January. The index currently shows that emissions of greenhouse gases per driver of newly purchased vehicles are now down 23 percent, overall, since October 2007.

Related Links:

• Fuel economy calculations, along with a graph and table of current and recent mpg: www.umich.edu/~umtriswt/EDI_sales-weighted-mpg.html
• Eco-Driving Index calculations, along with a graph and table of current and recent values: www.umich.edu/~umtriswt/EDI_values.html

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.