106 mpg 'air car' creates buzz, questions

You've heard of hybrids, electric cars and vehicles that can run on vegetable oil. But of all the contenders in the quest to produce the ultimate fuel-efficient car, this could be the first one to let you say, "Fill it up with air."

That's the idea behind the compressed air car, a vehicle its backers say could achieve a fuel economy of 106 miles per gallon.

Plenty of skepticism exists, but with many Americans trying to escape sticker shock at the gas pump, the concept is generating buzz.

The technology has been the focus of MDI, a European company founded in 1991 by a French inventor and former race car engineer.

New York-based Zero Pollution Motors is the first firm to obtain a license from MDI to produce the cars in the United States, pledging to deliver the first models in 2010 at a price tag of less than $18,000.

http://www.cnn.com/2008/TECH/08/08/air.car/index.html

According to the story, the car runs on compressed air at speeds less than 35 MPH. At speeds above 35 MPH, fuel is burned to heat the compressed air and expand it, thereby increasing its range.