(November 2009) Edmunds.com has submitted a recommendation to make new car window stickers more useful to car shoppers by highlighting usage costs rather than miles per gallon numbers.

The recommendation was submitted to the Environmental Protection Agency (EPA) and the Department of Energy and available for viewing at http://www.edmunds.com/industry-car-news/monthly-fuel-cost-letter.html

 Window stickers currently display "miles per gallon" ratings, undeniably useful for consumers looking to compare vehicle choices.  However, for an increasing number of vehicles, gallons of gasoline are not being consumed.  Under current proposals, all-electric vehicles and other alternative fuel vehicles are expected to be given "MPG-equivalent" ratings generated by complex algorithms that attempt to translate other forms of energy into a comparable measurement.

 "Consumers have used the existing MPG ratings primarily to get a sense of the relative cost of operating a vehicle on a day-to-day basis," Edmunds.com CEO Jeremy Anwyl told GreenCarAdvisor.com

"However, using energy equivalents can easily cause consumers to draw erroneous conclusions.   For example, a new Toyota Prius earns 50 MPG.  General Motors is reporting that its new Chevy Volt will possibly be rated at 230 MPG-equivalent.  From this consumers could reasonably assume the Prius is more than four times more costly to operate than the Volt.  But that would be wrong."

 The chart below sets forth the projected monthly fuel costs for a variety of vehicles.

"Looking at this analysis we find that electric vehicles do enjoy a cost advantage over their counterparts powered with other technologies — but this advantage is nowhere near as great as the proposed EPA ratings would imply," noted Anwyl.

 The EPA already provides "annual usage costs" data on window stickers, and makes the required assumptions necessary to do so. Edmunds.com suggests that consumers will benefit if the window stickers simply highlighted these amounts instead of the MPG numbers.  And when using EPA figures in marketing, automakers should be required to use EPA-provided monthly cost estimates.

While this proposal is being considered, Edmunds.com is providing a list of monthly fuel costs for all 2009 and 2010 model year vehicles so that shoppers can make realistic comparisons today (at http://www.edmunds.com/industry-car-news/fuel-mileage-equivalency.html). To produce this list, Edmunds.com's statisticians used data and assumptions that mirror those used in Edmunds.com's True Cost to Own® tool.