PEOPLE USED TO SAY it was impossible to cut energy use in American industry without crippling economic growth. They were wrong. Practically everyone said -- you heard it dozens of times -- that, higher prices or not, they certainly weren't going to cut back their driving. But a lot of them have done just that. A lot of people also said that Americans had made their whole pattern of national life so deeply dependent on oil and gasoline that no significant reductions could be made without severe disruptions of business and society. But, so far, there have been no great disruptions.

Energy conservation works, and the experience of the past several years is a demonstration of it. American industrial production rose 12 percent from 1973 to 1978. But in 1978, industry was using slightly less energy than it used in 1973. Most engineers think that the greatest gains still lie ahead, as the present generation of production machinery is retired and replaced with new models specifically designed for a time of rising fuel costs. On the highway, you can see the swing to smaller cars that get more miles to the gallon. In industry, less visibly but even faster, the same kind of swing to efficiency is taking place.

Speaking of cars and gasoline, this country has surprised itself by its ability to adjust to less deiving. Gasoline suplies over the sumer and right up to the present have been no higher than they were last May and June, when the lines at the filling stations were at their longest. The first reaction to the shortage was a rush to get in line and get a full tank. There was a spasm of hoarding throughout the distribution system. But, as the weeks passed, people got fed up with sitting in lines -- and the lines began to evaporate. The refineries weren't producing any more gasoline than they did last spring. People were just buying a little less. The average American car is apparently being driven about 175 miles a week, down from 190 miles a week last year.

In October, preliminary figures suggest, oil comsumption for all purposes in this country was running a bit over 17 million barrels a day. A year earlier, it was up to 18.4 million barrels a day. Almost half of that reduction is the result of less driving.

It's important not to sentimentalize conservation. For some people, life is a little chillier and a little less convenient than it used to be. But it's equally important to keep in mind that there has been a substantial drop in oil consumption without any drastic impact on American comfort and prosperity. The soaring price of oil is contributing to the slowdown of the economy. But the drop in oil consumption and, specifically, driving has not resulted in any sharp increase in unemployment or business failures or public protest. It will be reassuring to keep the past year's experience in mind if -- and it seems very likely -- there's another squeeze on the oil line next year.