"It's good gas," he said while fueling up at a station in this Twin Cities suburb. "I haven't noticed any difference in gas mileage performance or engine performance as well."

The station's sign showed the savings: $2.07 per gallon for unleaded and $1.62 for E85.

Interest in E85 has been growing recently because of spikes in gasoline prices. Promoters say it's not only cheaper, it reduces dependence on foreign oil and burns cleaner. And it's a boost to the Midwest farm economy because it is distilled mainly from corn.

More than 4 million flexible fuel vehicles — which can run on blends of up to 85 percent ethanol — are on the road in the United States, the government says.

In Hawai'i, most gasoline sold will contain 10 percent ethanol starting in April 2006, but at present the National Ethanol Vehicle Coalition doesn't list any Hawai'i outlets selling E85.

The number of places nationwide selling E85 is rising, said Tim Gerlach, director of outdoor air programs for the American Lung Association of Minnesota and a leader in the E85 push.

Minnesota has close to 150 E85 pumps, Gerlach said, more than any other state by far. Illinois, a top corn-producing state that has been another leader in promoting E85, has about 20 stations.

"It's mainly a Midwestern corn-ethanol thing right now but it is spreading, and I think once it catches on you're going to see a lot of attention on it," he said.

Availability on the East and West Coasts is likely to grow if Congress approves a proposed tax incentive for stations to install E85 equipment, said Michelle Kautz, spokeswoman for the National Ethanol Vehicle Coalition. That provision is part of the energy bill approved by the Senate on Tuesday, but is not in the House version and is one of several differences that must be reconciled in conference committee.

The National Ethanol Vehicle Coalition has a nationwide station locator on its Web site.

Availability isn't usually a problem for Sara Westberg, who drives a government-owned flexible fuel 2000 Ford Taurus for her job with the Minnesota Department of Health. She said that in the past year she'd rarely resorted to regular gasoline.

"I drive probably 20,000 miles a year, maybe more," she said. "So the E85 makes a huge difference for me — and for the state."

General Motors, Ford, DaimlerChrysler, Nissan, Isuzu and Mazda make flexible-fuel versions for certain models, sometimes only for fleet vehicles. The differences under the hood are relatively few, so prices are similar. But E85 should not be used in vehicles not designed for it.

One way to tell if a vehicle can use E85 is to check the owners manual. Many flexible-fuel cars also have decals inside the fuel door saying they can use it. The National Ethanol Vehicle Coalition keeps a comprehensive list on its Web site, as well as a guide for telling definitively from the vehicle identification number.

Mileage is somewhat lower with E85 depending on the vehicle, Gerlach said, ranging from 2 percent less for some newer vehicles to 17 percent less for some older engines. But drivers say the lower cost per gallon more than makes up for that. By comparison, the E85 Nye pumped into his car was 22 percent cheaper than regular unleaded at the same pump.

While regular gasoline prices have been rising, ethanol prices have stayed down because of a rapidly growing ethanol supply and federal tax subsidies. That's meant E85 running anywhere from 30 to 60 cents a gallon cheaper than gasoline.

Mike Jorgenson said he could save big money if he had a flexible-fuel vehicle for his daily 130-mile round-trip commute. His '97 Chevy Blazer gets a depressing 15.5 miles per gallon, he said, as he filled it up with regular unleaded from a pump that also offered E85 for 45 cents less.