Maybe you've seen the television commercial: A man, swaddled in layers of flab and flannel, shivers audibly. His dog, ditto. "If the chill of winter has thrown you into shock," intones the announcer, "it's time you asked {yourself}, 'What are you waiting for?' ... Get warmer. Call Washington Gas."

As happens every year, the winter war between the gas company and other heat providers is on. But this year there's an additional weapon. Soaring oil prices are giving natural gas heat a huge price advantage over heating oil, and Washington Gas Light Co., like other gas utilities, is exploiting the edge.

Washington Gas has stepped up advertising that encourages oil heat customers to convert to gas and is offering a deferred payment plan that allows homeowners to spread the cost of installing a new furnace and switching to gas -- usually $1,200 to $3,500 -- over five years of gas bills, with no payments until June.

News reports about how oil prices have doubled since Iraq invaded Kuwait Aug. 2 don't hurt the gas business either -- at current levels, gas industry officials said, heating oil is about four times as expensive as the equivalent amount of natural gas.

Washington Gas officials won't discuss specific numbers, but they said they're converting twice as many homes from oil to gas heat this year as they did a year ago.

"We've been flooded with calls," said John Raymond, a spokesman for the utility. "We have done some advertising, but we mostly attribute it to the Middle East situation, people worried about what's going to happen."

Not surprisingly, the gas company's efforts have heating oil distributors and dealers hot under the collar. Two-thirds of the homes within Washington Gas's service area already have gas heat, while oil accounts for just 11 percent of the total -- a relatively small amount compared with the Northeast, where oil heat dominates. The third major local heating source is electricity, which is more expensive than gas or oil, though cheaper to install.

So local oil industry officials are chary about losing any more business.

"Certainly, heating oil customers are looking at a winter of higher prices if the situation continues in the Middle East," said Lock Wills, president of Southern Maryland Oil Co., a La Plata, Md., heating oil firm. "But I think it's false and misleading for the gas folks to say that their prices are at historically low levels."

"Any impact that our committee has had by advertising and promotion has been blunted" by the higher prices, said Walter J. Meighan, chairman and president of Griffith Consumers Co., a large Cheverly-based oil distributor, and chairman of the Better Home Heat Council, an industry group.

Still, he said, "We haven't gotten as much reaction as we thought" to high prices. "We're not seeing the dramatic increases in switching."

At the moment, the numbers are on the side of natural gas. The wholesale price of home heating oil stands at about $1 a gallon, or $42 a barrel. The equivalent wholesale price of natural gas is about $11 a barrel, according to gas industry officials.

Most of the blame for the wide gap can be assigned to Iraqi President Saddam Hussein. Oil supplies aren't particularly tight right now, but prices have soared on the New York Mercantile Exchange, the central source for oil prices, in the past 2 1/2 months because of fears that the Iraqi leader's attack on Kuwait, and the U.S. response to his actions, will lead to war in the Middle East that could cause a dramatic oil shortage.

However, almost all U.S. natural gas supplies are produced domestically, so prices have stayed at pre-invasion levels. Moreover, an eight-year oversupply of gas in the United States continues to keep down prices, although some industry experts believe that the gas "bubble" is near its end.

Such a wide disparity in prices is unusual. Traditionally, gas and oil prices have been fairly close to each other over the years. But the Middle East crisis derailed that relationship.

The gap also has been aided by major changes in the natural gas market in the last seven years, including price decontrol, increased competition among producers and pipeline companies, expanded supply and, lately, soft demand.

Oil industry officials say they hope the advantage will be short-lived. They note that gas prices have yet to begin their annual seasonal rise -- experts expect gas to rise to just under $3 per thousand cubic feet by January from about $2 currently. "When the weather gets cold, prices will start to rise, and consumers shouldn't look at prices today -- they should look at what the prices will be this winter," Wills said.

Still, even at that level, gas prices would be way below the equivalent current oil price. And the oil dealers admit that their best hope is a settlement of the Middle East crisis that could bring oil prices down quickly.

"Everything depends on the president's resolution of the Middle East, as far as do we see a crash in prices or do they edge up," Griffith Consumers's Meighan said. "Then our question is, how long does it take a consumer to pay off his investment if he puts $2,000 into a new furnace and then gas tracks oil" prices?

"People have to weigh that front-end cost versus what you save, $100 or $200 a year," said Edwin Rothschild, director of Citizen Action, a consumer advocacy group. "You're better off investing in efficiency things to reduce your consumption rather than investing in a whole new system."

Oil industry officials also say there are questions about gas supply capabilities, especially if the weather gets very cold, as many long-range forecasts predict. For a number of reasons, gas supplies tend to run tight in extremely cold weather, and about 1,100 large commercial customers in the Washington area switch from gas to heating oil for brief periods most winters because of supply shortages.

Gas industry officials, however, point out that those customers always come back to gas, because it's cheaper. And they said supplies are ample this year. "All the reasonable forecasts for gas supply are that we have a lot of natural gas for use," said Nicholas J. Bush, president of the Natural Gas Supply Association, a Washington-based trade group representing gas producers.