University of Michigan graphic
The University of Michigan recently announced that average fuel economy of newly purchased vehicles hit an all time record high, averaging 24.1 miles per gallon during October, 2012.

The new record represents the highest level yet, up 4.0 mpg from October 2007 (the first month of monitoring by U-M). This 20% improvement in fuel economy (mpg) corresponds to a 17% reduction in fuel consumption (gallons per mile).

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 0.81 in August, an improvement of 19% since 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). Please visit this University of Michigan page for a brief description of what the EDI is, how it is calculated, and the current and recent values of the EDI.

The University notes that all values are now corrected for the changes in the EPA ratings for the Hyundai/Kia vehicles that were issued on November 2.