Gasohol -- a blend of 90 percent gasoline and 10 percent alcohol -- is sold in gas stations from coast to coast; in some places it's cheaper than pure gasoline, and in others it's the same price or more expensive.

You may have wondered if you can burn gasohol safely in your car, and what if any modifications to the engine will be needed. How will it affect performance? Are there any special problems? Gasohol's proponents say it can reduce our dependence on foreign oil, although the amount of ethyl alcohol (the type used in gasohol) produced is still minuscule compared to our daily gasoline consumption and many, if not all, of the plants that produce it are not as efficient as they could be.

So not only is the amount of ethyl alcohol produced a drop in the bucket, it very well may require more energy to produce it than it returns. It's also more expensive to produce than gasoline. But the Department of Enegry and other government agencies and people who are supposed to know say that with improved processing plants, and the increasing price of foreign oil, alcohol blended with gasoline will probably become increasingly widespread in the future. Even though ethyl alcohol is currently more expensive to produce than gasoline, gasohol at the pumps may be cheaper than gasoline in some places, because the government has eliminated some taxes from the gasohol -- artificially making it cheaper.

It won't hurt your motor, but whether your car will run better, the same or worse on gasohol depends on a lot of things.

On older cars in good running condition, gasohol may improve engine performance slightly. Older cars ran richer -- flowed more fuel through the carburetor at a given speed. Alcohol in the gasoline has a leaning effect on carburetion, so an older car may show a slight improvement in performance and mileage on gasohol.

On later-model cars, which are running about as lean as they can and still propel the car down the highway (because of emissions requirements), using gasohol may decrease performance somewhat. In general, if you run gasohol, expect anywhere from a 5 percent loss to a 5 percent gain in mileage.

The engine does not need to be modified to burn gasohol, and burning gasohol probably will not void your car's warranty (if your car is still under warranty). If you're concerned about this, check with your dealer first. Burning gasohol in Chrysler cars, for example, does not affect the warranty.

Still, there are a couple of points you should be aware of:

PHASE SEPARATION. A certain amount of water in your car's gas tank (or in the service station's storage tanks) can make the gasoline and alcohol separate. If you think you might have excessive water in your gas tank, you might want to have it drained before you start using gasohol.

FUEL FILTER. Alcohol can loosen rust, varnish and oxidized gasoline from gas tanks. If after burning a couple of tanks of gasohol you experience some engine performance problems (stumbling on acceleration, loss of power, etc.) take a look at the fuel filter. If it's clogged, replace it.