District gasoline dealers near the Maryland border experienced a painful drop in business yesterday as some motorists drove the extra mile to buy cheaper gasoline on the first day of the city's new 6 percent gasoline tax. b

The tax adds eight cents per gallon at current prices. Even before the new tax became effective, D.C. gas taxes were a penny higher than Maryland's -- meaning that yesterday most District stations were charging nine cents to a dime more than those in Maryland.

Full-service stations in the District were generally charging between $1.32 and $1.35 for a gallon of unleaded gasoline yesterday, while it could be found in Maryland for about $1.25 a gallon.

At Brentwood Gulf, about half a mile beyond the District line on Rhode Island Avenue, business was up by more than 30 percent, according to cashier Rhea Lamb. The station was crowded with cars with District license plates, many of them cabs whose drivers spend $25 to $30 a day on gasoline.

Cabdriver Arthur Elmes, 52, said he usually fills up at a station on Georgia Avenue NW in the District but yesterday he bought just $5 worth at his regular station -- because he was empty -- and then went out to Brentwood for the rest.

"I've got to avoid that tax," he said. "It takes gas to get out here, but it's still cheaper."

Lamb said that normally the station does around $750 in business before 1 p.m. Yesterday, she said, the station had sold more than $1,000 worth of gas during the same period.

Less than a mile away -- inside the District -- 56 year-old Stanley Anderson talked of selling the Exxon station he opened eight years ago.

Anderson's station is on Rhode Island Ave. N.E., no more than 200 feet inside the District.

"It' been awfully slow," he said. While a reporter talked to Anderson for 20 minutes yesterday, one car drove in. The customer bought a dollar's worth of gas.

Anderson said that of the 14 neighborhood businesses that buy gas from him regularly, six have called to cancel their accounts because of the new price differential. Those six customers usually buy nearly one-third of his 50,000 gallon-a-month allocation. Anderson said.

"I took care of my customers during the gas crisis, and they said they appreciated that" Anderson said. "They said they would probably stay with me if the difference was three or four cents. But not for a dime.

Anderson, who has lived in the District for 40 years, said he planned to lay off both of his employes at the end of the month and work the station by himself until he is able to sell it.A nearby auto dealership has asked about buying the station as a tax write-off, Anderson said.

"They came to see me again this morning, and asked if I was ready to talk about a deal," said Anderson. "I told them, 'Just about.'"

Kwan Kim, owner of an Exxon station just inside the District line on Georgia Ave. NE, said several persons drove in yesterday, but drove right out again after checking the prices. Kim, who bought the station two weeks ago, hoping the on-again, off-again tax wouldn't take effect, paid the tax himself on some kinds of gasoline to keep the customers he has.

But just beyond a large sign saying "Welcome to Silver Spring," Amoco station oowner Kenneth Kadala said he expects to order 20,000 extra gallons of gas this month to supplement his regular 40,000-gallon allotment. Kadala said that normally a third of his customers are from the District, but yesterday, the figure was two-thirds.

Still, Kadala said he doesn't like the tax.

"It's pitting brother against brother," he said. "The tax is definitely throwing business my way, but it's bad money. You can't make money out of other people's bad luck."

City officials said they had anticipated an overall decline in gasoline consumption in the District of about 16 percent because of the tax. But they have figured this into their projections that the tax will raise $13 million in revenues for the District.

"Of course, the impact would be greater near the (Maryland) line," said Carolyn L. Smith, director of the city's Department of Finance and Revenue. "Stations in the inner city may feel no impact at all."

She suggested that stations near the border try decreasing their profit margins, but some stations owners said this is impossible for them. Most service stations simply added the eight cent tax at the pump, rather than try to compute it after the sale is made.

Smith's deputy, Ed Meyers, said there apparently were no major problelms reported in administering the tax -- just phone calls from stations near the border who said their business was disappearing.