Whatever happened to compressed natural gas? In a word, politics, according to a Boston Globe investigation, which noted that despite the fact that European drivers can choose vehicles from eight separate manufacturers, the United States has exactly one CNG-powered car on sale—the Honda Civic GX—of which exactly 459 copies were sold last year. And CNG sells for about $2.69 per gallon, which is a couple of bucks less than what gasoline, diesel, and biofuels sell for today.

"In the United States, use of natural-gas-powered vehicles is limited mostly to commercial and municipal fleets, including 360 MBTA buses, but such vehicles are making a significant dent in the European consumer auto market as oil trades above $130 a barrel," the report said. "The fuel, compressed at high pressures and called CNG, burns cleaner and produces fewer greenhouse gas emissions than other petroleum fuels."

But there's a distinct lack of natural gas fueling stations in our country. Automakers have tried selling CNG-powered cars in the past, but in each case eventually pulled them off the market due to that fact, as well as their high manufacturing costs.

"The president gets up there and says, 'It's going to be ethanol, it's going to be hydrogen.' Well, when's the last time you heard him say it's going to be natural gas?" said Richard Kolodziej, who runs the natural-gas lobby NGVAmerica. "We don't get that kind of visibility."

(Image credit: Boston Globe)