The average fuel economy (window-sticker value) of new vehicles sold in the US in March was 25.4 mpg (9.26 l/100km)—a 0.3 mpg improvement from the revised value for February and the best mark yet, according to the monthly report from University of Michigan Transportation Research Institute (UMTRI) researchers Dr. Michael Sivak and Brandon Schoettle.

This improvement likely reflects, in part, the recent increase in the price of gasoline, they suggested. Vehicle fuel economy is 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—edged upward to 0.80 during January, on the heels of its two best months at 0.78 during November and December (the lower the value the better).

This value indicates that the average new-vehicle buyer produced 20% lower emissions in January 2014 than in October 2007. 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).