Gasoline prices in the Washington area have dropped to a six-year low and are falling so rapidly that a survey released yesterday is already out of date. Before summer, prices could dip another 20 cents, according to projections by the American Automobile Association.

Average gasoline prices in the area have fallen 11.5 cents a gallon since December, according to a survey released yesterday by AAA's Potomac Chapter. The biggest drop was in the price of unleaded gasoline at self-service pumps, which averaged $1.05 per gallon, 15 cents less than three months ago, according to the survey. The latest survey also found average per gallon prices of 99 cents for leaded gasoline and $1.21 for premium gasoline.

The AAA survey of 100 area gasoline stations was completed last Thursday, but industry specialists said individual gasoline stations in the area are dropping prices daily by as much as 5 cents a gallon.

"The lowest price when we did the survey was 91.9 [cents]," AAA spokesman Douglas Neilson said yesterday.

On Georgia Avenue in Silver Spring, Amoco station owner Reza Kolahdouzan dropped his price for leaded gasoline yesterday morning to what AAA officials said was probably then the lowest inside the Beltway: 87 cents a gallon.

In some of the area's outer counties, such as Fauquier in Virginia, stations were charging 87 cents yesterday for the higher priced unleaded gasoline.

Next door to Kolahdouzan's station, Gulf station owner Glen Cade was charging a penny more than Kolahdouzan for all grades of gasoline yesterday.

But Cade, whose station was the backdrop for the press conference on the AAA findings, said he planned to drop his prices below his nearest competitor that night, his second price change in 24 hours.

"I was the lowest one around here until 9 a.m.," Cade said yesterday. "It's been like this every day, every week."

Despite the daily declines, area prices are still above those charged in other parts of the country. Unleaded gasoline is available for as little as 60 cents a gallon Omaha and other cities.

Washington area prices have historically been higher than those in other regions because of fewer independent stations, higher local taxes, less competition and the lack of middlemen or "jobbers" who sell to individual station owners at prices below those of the major oil companies.

Yesterday, service station representatives said one of the reasons for the disparity between area and nationwide prices is higher wholesale charges. According to the AAA survey, while wholesale charges to local service stations are 13 cents a gallon less than they were in December, wholesale costs have dropped nationally by almost 23 cents since the beginning of the year.

"The biggest factor [in higher prices] is the oil company price. That's pure and simply it," according to Michael DeSanto, governmental affairs director of the Greater Washington Metropolitan Service Station Dealers Association. "The prices you are seeing are bare-bones, bottom prices for dealers to compete," he said.

Gulf owner Cabe said he was selling his leaded fuel yesterday at cost, for 88.9 cents a gallon. But by selling unleaded for 95 cents a gallon and premium for $1.12, he makes 6- and 17-cent profits respectively, he said.

Gasoline prices typically fall between December and March, however, when motorists buy less fuel. The average price of gasoline in the area a year ago was only 6 cents higher than today's prices, according to the AAA.

Industry specialists predict that a heavy demand during the summer will reduce gasoline supplies, slowing a decline that could take prices in the Washington area to 70 cents a gallon even if world oil prices stabilize.

Businessmen Kolahdouzan and Cabe are contributing: "Today when I came in I saw his price and I went down," Kolahdouzan said yesterday. "I try to keep my prices a penny below him no matter what."