Sen. Henry M. Jackson (D-Wash.) warned yesterday that President Carter's program to decontrol domestic oil prices will cost American motorists an additinal 15 to 20 cents a gallon by 1981.

That would be 3 to 4 times more than what the White House claims.

"We have two differing figures," Jackson, chairman of the Senate Energy Committee, told a reporter.He recalled that previous administration estimates of other decontrol measures had been too low.

"In the past," he said, "we have understimated the price impact [of decontrol] of heating oil and aviation gasoline."

At a White House briefing for reporters Thursday, a senior administration official said the decontrol package would raise gasoline prices 4 to 5 cents by September 1981, when controls expire. If Jackson is correct, Americans will be paying as much as $1 a gallon for unleaded premium gasoline before domestic price controls are removed totally.

Asked whether Congress will act on Carter's appeal to Congress to enact a windfall profit tax that would return 50 percent of the oil companies' additional earnings under decontrol, Jackson said flatly that Congress "won't pass a windfall profits tax."

In the House, Rep. John D. Dingell (D-Mich), chairman of the Commerce subcommittee on energy and power, offered a similar view, saying, "Prospects are not good for passage."

Although the tax measure has yet to be sent to the Hill formally, the proposal was assailed vigorously by the Business Roundtable, a powerful industry-wide lobbying group, a number of major and independent oil companies and some members of Congress.

"I am disappointed the president wishes to tax these proceeds, and I hope the Congress carefully considers the needs of the nation as it reviews the administration's proposal," O. P. Thomas, head of the Business Roundtable's Energy Users Task Force and chairman of B. F. Goodrich Co., said yesterday in Akron.

Unlike the windfall profits tax, which must be passed by Congress, decontrolling of oil prices administratively by Carter can begin on June 1, under existing law.

Not all the reaction to Carter's energy plan was negative.

An ABC News/Louis Harris poll on energy, conducted just after Carter's energy address to the nation Thursday night, indicates that a 73-to-18 percent majority approves of his new program to make the United States more selfsufficient in its energy use.

House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass) said yesterday he could live with Carter's decontrol plan if the windfall is passed. "No possible decision could be popular," the speaker said.

Meanwhile, House Minority Leader John J. Rhodes (R-Ariz). gave the president unexpected support, saying that Congress will pass a plan to prevent the oil industry from earning windfall profits, but with modifications.

Sens. Bob Dole (R-Kan.) and John H. Chafee (R-R.I.) also asked fellow Republicans in the Senate not to reject the windfall tax out of hand, asking that the tax "be structured to ensure increased exploration and production of domestic oil."

The strongest criticism leveled at Carter's plan came from House and Senate liberals.

Sen. Edward M. Kennedy (D-Mass.) said, "It is sad to see the president deliver this unnecessary self-inflicted wound to his own anti-inflation program."

And in the House, Rep. Toby Moffett (D-Conn.) warned that the administration's package of standby mandatory conservation measures-gasoline rationing, mandatory thermostat settings, a ban on decorative lighting and weekend gasoline station closing-are likely to run into new opposition. "They will be turned down-everything but thermostat settings," Moffett said in a telephone interview.

The president has called on Congress to approve all four measures, and said that he will ask to have thermostats in nonresidential buildings set at 80 or 65 degrees, depending on seasons.

Seeking to answer some of the criticisms of the president's proposals, the administration's chief inflation fighter, Alfred E. Kahn, said yesterday that higher oil prices would have beneficial "offsets," such as reduced reliance on imports and ultimately some downward pressure on world oil prices.

As for the windfall profits tax, Kahn told reporters, "I want consumers . . . to get out there and fight like hell for that tax."

Carter had been urged by some members of Congress and a few of his own advisers to make decontrol dependent on Congress first passing a windfall profits tax. He rejected that advice.

One of the strongest criticisms leveled at the carter plan came from House Ways and Means Committee member Fortney H. (Pete) Stark (D-Calif.). "Carter sold out to the oil companies and [Department of Energy Secretary James R.] Schlesinger," Stark said. He estimated that about 16 of 36 members of the House tax-voting panel would vote against Carter's version of the windfall profits tax. "You only have to pick up two more to defeat it," he said. CAPTION: Picture 1, Reps. Clarence J. Brown (R-Ohio), Rhodes and Joseph M. McDade (R-Pa.) during news conference on energy. By James K. W. Atherton-The Washington Post; Picture 2, Energy Secretary Schlesinger discusses higher oil prices on the "Today" show. AP