Mike Gaffa, a 39-year-old Continental Airlines reservation clerk, bought a used Ford F-150 pickup for $10,500. The vehicle came with a bonus: a previous owner added three extra tanks that fill the bed of his pickup.

"I don't even keep track of gasoline prices anymore," Gaffa boasted. "You'd be hard-pressed to find another vehicle that can go 600 miles on a fill-up."

And when he runs out of natural gas, he can switch over to a regular gasoline tank for a total range of more than 850 miles.

Utah has caught the attention of Honda, which can't make CNG-equipped Civic GXs fast enough at an Ohio plant. For now, it makes the compact available for sale to individuals only in California and New York, but executives say Utah could be next on their list.

Aside from fleet sales, no other automaker offers a CNG-powered car in the U.S.

Most Utah buyers must turn to the used-car market. They are tracking down vehicles on the Internet, some made earlier by the Detroit automakers. Some dealers here are hauling used CNG vehicles to Utah by the truckload.

"The demand in Utah is huge," Kolodziej said. "It's sucking all the used vehicles from around the country."