GASOHOL WILL RUN your car very nicely, and expanding its production is a good idea-up to a point. Gasohol is a mixture of gasoline and alcohol made, usually, from grain. The point at which it becomes a bad idea is when it threatens to cut into food supplies. A House Agriculture subcommittee has been holding hearings on a bill that would put the country into the gasohol business in a big way with, among other things, sharply increased price supports for corn. The bill tries to solve one shortage by risking another of a much more serious kind.

The enthusiasm for gasohol is warmest in those parts of the country that produce corn. It is widely felt there that farm prices are much too low. Some of the farmers see the automobile as a potential customer that will strengthen their markets. But in other parts of the country, the prevailing opinion seems to be that food costs are already high enough.

Alcohol can also be made from a great variety of wastes-garbage, the leftovers from food processing, grain that is spoiled or substandard. A small distillery can be fueled with almost any sort of trash that will burn. If the gasohol industry stays within those limits, the administration estimates, gasohol might be 3 percent of gasoline consumption by the early 1980s. But if it goes onto a larger scale, it begins to require commercial ingredients and fuels.Under those circumstances, more oil would go into raising the crops and running the distillery than the gasohol can save.

This country possesses the largest expanses of first-rate agricultural land in the world, and it has responsbilities not only to feed its own people but many others abroad. To divert good grain from the food markets to make motor fuel would be a wanton waste. It would attempt to mitigate the shortages of gasoline here by aggravating food shortages around the world.

Gasoline, it can be argued, is a necessity for many Americans. But among all the things that are necessity for many Americans. But among all the things that are necessary to daily life, it hardly ranks first. At the top of the list are the absolute and immediate necessities-food, air and water. It is striking that the large-scale solutions proposed for the energy shortages almost invariably jeopardize water supplies or the quality of the air or, as in this case, food stocks. As the country tries to cope with short deliveries of gasoline, it's useful to remember that some necessities of life are more necessary than others.