(Phys.org) —For the second month in a row, fuel economy of new vehicles sold in the United States remains at a record high, say researchers at the University of Michigan Transportation Research Institute.

Average fuel economy (window-sticker values) of cars, , minivans and SUVs purchased in February held steady at 24.5 mpg, the same as in January and up 4.4 mpg from October 2007, the first month of monitoring by UMTRI researchers Michael Sivak and Brandon Schoettle.

In addition to average fuel economy, Sivak and Schoettle issued their monthly update of their national Eco-Driving Index, which estimates the average monthly emissions generated by an individual U.S. driver. 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.

During December, the EDI stayed at 0.80 for the third straight month after a record-setting 0.79 in September (the lower the value, the better). The index currently shows that emissions of per driver of newly purchased vehicles are down 20 percent, overall, since October 2007.

More information: Fuel economy calculations, along with a graph and table of current and recent mpg: www.umich.edu/~umtriswt/EDI_sa … es-weighted-mpg.html

Eco-Driving Index calculations, along with a graph and table of current and recent values: www.umich.edu/~umtriswt/EDI_values.html