AT LEAST FIVE different service stations in Washington have come up with the same bad idea for making money to offset decreases in their gasoline sales: they're seeking licenses to sell beer and wine--which has got to be the worst possible mixer for a tankful of gas short of hard liquor. True, many markets in the states are permitted to dispense six-packs and high-octane on the same site; and on more than a few blocks in the District, a thirsty motorist can practically one-stop-shop for gas and beer, anyway.

Besides, the station owners argue, drunk driving won't necessarily increase if they are allowed to sell beer and wine. Perhaps not, but it would take some awfully compelling evidence to make a case that drunk driving would decrease as a result of their sales. It is also difficult to prove that any neighborhood in this city is short on places to buy beer and wine. In fact, the biggest concern these days is the relative convenience of these stores already to the suburbs--where raising of the drinking ages is sure to send more teen-agers than ever into the city in their cars.

The Metropolitan Police would remind us that alcohol was a factor in 16 traffic fatalities in the city last year. And as many neighborhood civic organizations have noted in their protests against the license applications, at a time when the country is trying to curb drunk driving, the District should not be embarking on a program that even appears to sanction driving and drinking at the same time.

Sentiment within the service station industry is mixed. Paul Longley, president of the Greater Washington-Maryland Service Station Association, is on record against granting the beer and wine licenses: "We need to make it as hard as possible for people behind the wheel to get hold of alcohol." Legislation outlawing any sale of alcoholic beverages at service stations is under consideration by the D.C. Council. It should be passed.