According to a University of Michigan study, fuel economy of newly purchased vehicles hit a new record all-time high in January.

The average fuel-economy (window-sticker) value of new vehicles sold in the U.S. in January reached a record of 24.5 mpg--up 0.4 mpg from the revised December value and up 4.4 mpg (or 22%) from the value in October 2007 (the first month of our monitoring). The recent improvements reflect the improved fuel economy of the 2013 model year vehicles.

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--stood at 0.82 in November. This value indicates an improvement of 18% since October 2007. 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 average sales-weighted fuel economy was calculated from the monthly sales of individual models of light-duty vehicles (cars, SUVs, vans, and pickup trucks) and the combined city/highway fuel-economy ratings published in the EPA Fuel Economy Guide (i.e., window sticker ratings) for the respective models.

For both monthly and model year averages, sales-weighted arithmetic means were calculated. (The arithmetic mean was used here to determine the average of window sticker ratings, not the average fuel consumption rate.) The fuel-economy information was available for 99.8% of vehicles purchased.