The average fuel economy (window-sticker value) of new vehicles sold in the US in January 2016 was 25.1 mpg—up 0.2 mpg from the value for December 2015, and the first increase in eight months, according to the latest monthly report from Dr. Michael Sivak and Brandon Schoettle at University of Michigan Transportation Research Institute (UMTRI). This increase likely reflects the month-to-month seasonal decrease in sales of pickup trucks and SUVs, they said. Fuel economy is down 0.7 mpg from the peak reached in August 2014, but still up 5.0 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 0.82 in November 2015, down 0.01 from the revised value for October 2015 (the lower the value the better). This value indicates that the average new-vehicle driver produced 18% lower emissions in November 2015 than in October 2007, but 4% higher emissions than the record low reached in August 2014.
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).