Edmunds.com wants to help customers better compare vehicle efficiency online

The debate over how to revise fuel-economy sticker ratings to accommodate new fuels continues, with auto shopping website Edmunds.com now asking the government to mandate a figure based on the cost of a typical month of operation.

Such a rating, it says, would let consumers compare vehicles regardless of the fuel they use.

The Environmental Protection Agency is studying formulas that could accurately tell people how fuel-efficient electric vehicles are and compare them with other types of cars. Because advanced electric cars will run only partially, or not at all, on gas, "miles per gallon" makes no sense.

Edmunds.com CEO Jeremy Anwyl says the EPA should consider a cost-to-operate figure that would let consumers compare what they'd spend on energy for a vehicle, whether it uses gasoline, electricity, hydrogen, ethanol or some combination. The current "mpg" number is useful because consumers can compare efficiency among cars. That comparison could be lost, he says, if the EPA adopts multiple ratings or numbers that don't accurately reflect the cost of operation.

For example, General Motors, using an EPA draft proposal, calculated its electric Chevy Volt will get 230 mpg. Comparing that with a Toyota Prius, rated at 50 mpg, makes it appear the Volt is at least four times cheaper to run.

But the Volt will cost about $48 a month for the plug-in charge and gas vs. about $62 a month to fuel the non-plug-in Prius, according to Edmunds.com's analysis.

"There's still a difference, but it's not as large as the mileage ratings would suggest," Anwyl says.

The EPA is expected to rule on the matter by the end of 2009 or early 2010. The National Renewable Energy Laboratory, a government agency working with the EPA on the issue, has said they believe the new rating system will give buyers two pieces of data, although what they will be has yet to be decided.

It matters to automakers, too. GM has been touting the 230 mpg figure for the Volt, even though it hasn't been confirmed by regulators. And Nissan says its Leaf will get 367 mpg. Nissan used different proposed government formulas for its figures.

Whatever the government decides, Anwyl says, Edmunds figures, which it will calculate based on average fuel and electricity prices and assuming people drive 1,000 miles a month, will be useful for car buyers.

That's why Edmunds plans to post the numbers on its website to help buyers compare vehicles.

Source: USAToday