Nationwide gas prices are averaging roughly $3.63 as the summer months approach, not an outrageous figure compared to recent spikes in oil costs. However, with those prices soaring well over $4 in some metropolitan areas, drivers will be looking for relief, both for their wallets.

That relief could take different forms, from an increase in public transportation use to a larger number of cyclists out on the roads, all the way to a boost for ever-more attractive hybrid and electric car models. But while electric cars can help drivers save on fuel costs–and while the government is encouraging their wider use–a report published Tuesday by the USA Today says that energy-efficient cars may not be as environmentally-friendly as advertised.

On Tuesday, the United States Department of Energy reported that electric vehicles can cut fuel costs by as much as two-thirds: while most drivers are paying in the high $3 or low-to-mid $4 range for gas, the energy department’s report noted that users of electric cars are only coughing up a cool $1.14.

That number has been grabbing headlines, with electric car manufacturers shoehorning it into their PR campaigns, and numerous advocates of alternative energy using it as a new-found battle cry.

But while a $2 to $3 price cut per gallon indicates the kind of wide-scale savings that would attract any driver, the USA Today cautioned readers not to take the price differences as the deciding factor for the electric car argument. According to the report, penned by journalist James R. Healey, doing so would be to make the mistake of equating “cheap fuel” with “clean fuel.”

“The reason electric cars are so cheap to run is because of cheap electricity to recharge their batteries,” Healey wrote.  “The reason electricity is cheap is because of cheap, if not always clean-burning, coal, and cheap, if not necessarily carbon-emission-free, natural gas.”

In the article, Healey argues that electric cars burn fuel every bit as carbon-based (and climate-affecting) as the gas that burns in the majority of highway vehicles. And while it’s probably unrealistic to expect still-recent electric car models (such as the Chevrolet Volt) to provide an entirely clean alternative to fossil fuels, Healey’s claim, that electric cars are two-thirds powered by dirty fuels, is eye-opening.

But even if electric cars were 100% friendly to the environment, the $1.14 fuel cost figure would probably still be misleading due to the higher vehicle costs that those electric models carry. Electric and hybrid cars are expensive–the cheapest Chevy Volt demands nearly $30,000–as are the devices and batteries that power them. And while electric charging locations are becoming more common at fuel service stations, the electric car niche has a long way to go before it can match gas-powered vehicles in pure convenience.