Steve Williams does what millions of American motorists can't: Fill up on cheaper, ethanol-based fuel from a local gas station.

Advocates, including farmers and President Bush, have offered E85 — a blend of 85 percent ethanol and gasoline — as an affordable way to help the nation grow itself toward energy independence with a cleaner-burning fuel. They would like to see more people like Williams, who filled up his 2003 Ford Explorer with E85 on a recent morning.

But there's a big hitch for this fuel of the future. There are too few pumps. While there are about 5 million "flexible fuel" vehicles on U.S. roads that can handle E85, there are only 1,145 public stations that offer the fuel nationwide, according to the National Ethanol Vehicle Coalition. Meanwhile, domestic automakers have promised to double their production of flexible-fuel vehicles by 2010.

The nation's roughly 167,000 retail gas outlets have been slow to invest the tens of thousands of dollars it takes to add E85 — especially when certification for the dispensers is in limbo and the market is so new. Many drivers don't even know their recent-model flexible fuel cars can handle E85.

"A lot of times a car is a person's largest investment, so they're cautious. 'I'm putting alcohol in there? What!? Are you kidding?'" said Christian King, whose Mobil stations in Albany and 70 miles north in Warrensburg are the only ones in New York offering E85 to the public.

E85 is cheaper than regular unleaded gasoline. King's station near the University at Albany recently retailed E85 for $2.599 a gallon versus $3.149 for regular unleaded. But since ethanol has less energy than gasoline, fuel economy drops 10 to 15 percent when cars run on E85.

Michelle Kautz, deputy director of the ethanol coalition, said E85 needs to be priced proportionately less than standard gasoline to provide the value to drivers. She said ethanol prices tend to be lower in the Midwest corn belt, but higher on the coasts because of transportation costs. There are no pipelines to transport ethanol, so the fuel has to be trucked or shipped by rail.

New York officials tried to give E85 a boost through a series of incentives last year under former Gov. George Pataki, who made ethanol a signature environmental issue. New York waived the roughly 40 cents a gallon in state gasoline taxes, offered to pay up to 50 percent of the installation costs for station owners up to $50,000, and approved a law giving stations the legal right to sell alternative fuels from outside distributors.

Despite all the effort, King in May became the first station owner in New York to offer E85 to the general public. Ralph Bombardiere of the New York State Association of Service Stations and Repair Shops said his members have been slow to sink money into dispensers and tanks because of "unknowns" in the market.

"They shy away from making the investment because no one knows how much product they're going to sell," he said.

Oil companies have done little to promote E85, which, after all, is a product they do not make. But consumers can still buy the alternative fuel at "branded" stations selling gasoline from big oil companies, like the Albany Mobil.

Exxon Mobil Corp. allows E85 sales at branded stations as long as long certain conditions are met, such as making sure the E85 is clearly marked as a non-Exxon Mobil product, said company spokeswoman Prem Nair. She said the company wants to make sure motorists don't accidentally fill up with a fuel their vehicle cannot handle.

"This is a product that we cannot testify to because we don't manufacture or supply them," said Nair, who was aware of about 20 branded Exxon Mobil sites either selling E85 or planning to.

Complicating matters is that Underwriters Laboratories since last October has been undergoing a lengthy review to see if E85 dispensers are worthy of the UL seal. The widely respected safety and standards lab — the little, round "UL" mark appears on everything from smoke detectors to cribs — was concerned that ethanol could corrode fuel dispensers. Stations can still put the pumps in with local approval. But a lack of certification — and the attending potential of liability issues — has had a chilling effect.

"The UL decertification has hindered us significantly," Kautz said.

Some larger box-store retailers were close to adding a significant number of E85 fueling stations before October, she said, but "once they heard of the UL decertification, they stopped."

In New York, the UL move sidetracked a plan to offer E85 at 10 rest stops in the New York State Thruway by the end of this year. One unit in New Baltimore, N.Y. sits unused and construction in nine other places has been halted as the Thruway Authority awaits certification.

The monthslong certification process has been frustrating for ethanol backers. In March, 14 farm-state senators urged UL to certify the dispensers.

John Drengenberg, manager of consumer affairs at UL, said E85 certification is a priority. But he stressed that it's not like approving a new toaster since they have to create a new set of safety standards.

"This is just the way that safety standards are developed," Drengenberg said. "We don't cut corners."

The lab expects to finish its certification standards by the end of this year.