Average fuel economy (window-sticker value) of new vehicles sold in the US in May 2016 was 25.4 mpg (9.26 l/100 km)—up 0.2 mpg from the value for April 2016, according to the latest monthly report from Dr. Michael Sivak and Brandon Schoettle at University of Michigan Transportation Research Institute (UMTRI). This 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, they suggested.
Fuel economy is down 0.4 mpg from the peak reached in August 2014, but still up 5.3 mpg since October 2007 (the first month of their monitoring).
The University of Michigan Eco-Driving Index (EDI)—an index that estimates the average monthly emissions of greenhouse gases generated by an individual US driver—was 0.84 in March 2016, up 0.03 from the value for February 2016 (the lower the value the better). This value indicates that the average new-vehicle driver produced 16% lower emissions in March 2016 than in October 2007, but 6% higher emissions than the record low reached in both August 2014 and August 2015.
The EDI takes into account both vehicle fuel economy and distance driven (the latter relying on data that are published with a two-month lag).