Janet Guthrie has been pouring methanol into her race car's fuel tank since 1977, when she became the first woman to drive in the Indianapolis 500.

"You're obliged to run methanol at the speedway," notes Guthrie, 43, "because it's safer fuel. It burns cooler and is not as explosive as gas."

Last week she drove an alcohol-powered "regular" car 3,000 miles across country -- from Los Angeles to Washington, D.C. -- to demonstrate "that it's techonologically feasible to run a car on the alcohol we produce right here in this country."

Guthrie was one of four drivers -- and two pilots -- who marked American Energy Week by traveling in a cross-country caravan of alcohol-fueled vehicles. The cars, borrowed from the Ford Motor Co. Experimental Fuel Fleet, and their fuels:

Mercury Lynx: modified to run on pure ethanol (an alcohol produced from grain or agricultural wastes);

Ford Escort: modified to operate on pure methanol (an alcohol made from wood, coal or natural gas);

Ford Escort: burning gasohol comprised of 10 percent ethanol and 90 percent gasoline (standard mixture sold in commerical gasohol pumps);

Mercury Lynx: gasohol comprised of 8 percent methanol, 90 percent gasoline and small percentage of t-Butanol (a petroleum product that eliminates problems of separation of the methanol and gasoline).

A single-engine airplane using pure ethanol, piloted by astronaut Gordon Cooper and Bill Paynter, followed the car caravan when weather permitted. The alcohol fuels were supplied by Mar-Cam Industries, United Energy Co., Diamond Shamrock Corp. and U.S. Alcohol.

"There's ablolutely no difference in performance between alcohol fuels and gasoline," says Guthrie, who drove the ethanol-powered Lynx."You couldn't tell what's in the tank from driving it, expect the exhaust (from the alcohol fuels) smell funny.

"The engine ran very cool, even going up mountains, with no knocking or pinging. Alcohol has a higher octane rating, is very clean-burning and can be more efficient in the engine."

The caravan stopped in 17 cities to talk with schoolchildren, citizens groups, civic organizations and politicans. "Everywhere we went," Guthrie says, "there was enormous grassroots interest in alcohol fuels.

"Truckers would call us on their CBs to ask 'What're you burning?' and 'How's it running?' People would follow us into rest stops to talk about the cars and tell us their alcohol fuel stories.

"A farm couple in Oklahoma asked me to get Washington moving on alcohol fuel to get rid of their surplus grain. We heard about a school bus in Massachusetts that runs on alcohol.

"People everywhere seemed interested in using America's resources and not sending any more money to Arab countries."

While methanol and ethanol "are equally good fuels," says Ford principal staff engineer Roberta Nichols, "we lean toward methanol because of our country's tremendous resources of coal and natural gas. Also, it's cheaper to produce than ethanol."

Although alcohol is a more efficient and cleaner fuel than gasoline, she notes that it results in lower mileage than petroleum fuels. Methanol gets about 60 percent and ethanol about 85 percent of the mileage delivered by gasoline.

Methanol -- available through chemical -- supply companies -- sells for about $1 a gallon and ethanol for about $1.80. "But when these fuels are produced in sufficient quantities to support a nationwide fuel system," says Nichols, "we would expect the price to drop."

A gas-fueled car, she says, can be switched back and forth between standard gasohol and gasoline with no problem. But converting a car that runs on gas to operate on the pure alcohol fuels (methanol or ethanol) "costs about $2,000 per vehicle, which is not economically sensible.

"But the parts for an alcohol-fueled car are no more expensive than for a gas-fueled car. So if you're running a production line, an alcohol-fueled car would cost no more to build."

(A gas-fueled car could be converted to run on alcohol with some minor modifications to the carburetor and timing, says Nichols, but would not take full advantage of the alcohol fuel's efficiency and engine parts that come in contact with the alcohol could be damaged.)

Ford manufactures in Brazil an alcohol-fueled car (Corcel) that sells for about $5,500. About 60 percent of Ford's sales in Brazil -- "a leader in converting to an alcohol-fueled fleet" -- are in alcohol-fueled cars. l

"They lack domestic oil," says Nichols, "but they've got lots of sugar that can be made into ethanol. Their goal is to become energy self-sufficient by 1985, and it looks like they'll make it."

The limited availability of alcohol, she says, "makes it impractical for the company to produce these vehicles in the United States at the present time."

But Ford is working with independent groups who want to experiment with alcohol-fueled vehicles. One such group is Los Angeles County, which plans to assemble a fleet of 40 methanol-fueled Escorts.

"Because of the long lead times required to build production facilities and work out the complex supply and distribution systems," says Nichols, "the most optimistic forecasts say, if we started today, it would be some time in the 1990s before we could approach energy independence."