According to a monthly report by Michael Sivak and Brandon Schoettle from the University of Michigan, the average fuel economy of newly purchased vehicles declined during the month of April.

The average fuel-economy (window-sticker) value of new vehicles sold in the U.S. in April was 24.5 mpg. This value is down 0.1 mpg from the record high reached in March, likely reflecting the recent decrease in the price of gasoline. Despite this small drop, the fuel economy is up 4.4 mpg since October 2007 (the first month of our monitoring). For a description of the calculations and the recent mpg values, click here.

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 February. 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). Please click here for a brief description of what the EDI is, how it is calculated, and the current and recent values of the EDI.

According to GasBuddy data, the price of gasoline during the month of April declined 11 cents per gallon, and since prices peaked in February, the U.S. average has shed 23c/gal, likely leading to the shift in priorities of American's when looking at a new vehicle.

However, as Americans look at gas guzzlers and less fuel efficient vehicles, gasoline demand may rebound, and cause those motorists a dizzy ride as they become trapped in a less fuel efficient vehicle as prices could rise should demand pick back up.