The average fuel economy (window-sticker value) of new vehicles sold in the US in September was 25.2 mpg (9.33 l/100 km)—down 0.1 mpg from the value for August, according to the latest monthly report from Dr. Michael Sivak and Brandon Schoettle at University of Michigan Transportation Research Institute (UMTRI) This decline likely reflects the increased proportion of light trucks among the vehicles sold, they suggested.
Fuel economy is down 0.6 mpg from the peak reached in August 2014, but still up 5.1 mpg since October 2007 (the first month of their monitoring). The model year 2016 average was 25.3 mpg (9.29 l/100 km)—the same as model years 2015 and 2014.
The University of Michigan Eco-Driving Index (EDI)—an index that estimates the average monthly emissions of greenhouse gases generated by an individual U.S. driver—was 0.82 in July 2016, down 0.01 from the value for June 2016 (the lower the value the better). This value indicates that the average new-vehicle driver produced 18% lower emissions in July 2016 than in October 2007, but 4% 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).