New government ads proclaim that the increased energy conservation President Bush is pushing amid the Persian Gulf war can come with no pain if everyone helps a little.

They say millions of gallons of oil can be saved daily through just checking air tire pressure, driving five miles an hour slower, using lower octane fuel and convincing drivers with more than one car to use the most gas-efficient vehicle more often.The only large lifestyle change promoted at all in the new nationwide Department of Energy ads is the increased use of car pools. The government has spent $500,000 on that ad campaign, which would otherwise cost $14 million, because of volunteer design by the Advertising Council and free space from the media.

But critics say the government is not being aggressive enough if it wants to achieve true conservation.

"I think they may as well have saved their $500,000. I've never seen government by exhortation work. It was something favored by the Soviets," said Llewellyn King, publisher of Energy Daily.

He said the only way to really achieve conservation would be to make it necessary economically by imposing a heavy gasoline tax of about 50 cents per gallon - which he admits is politically virtually impossible.

And Kenneth Bosson with the Public Citizen Critical Mass Energy Project, founded by consumer advocate Ralph Nader, agreed that the ads and President Bush are not aggressive enough. "Anyone driving around in a boat that gets two miles to the gallon at the time of the Iraqi invasion is not doing enough."

But Mary Joy Jameson, Department of Energy director of public affairs, said her department and its advertising agency of Bozell Inc. believed it would have the most success if it tried to persuade Americans to make only small changes in their habits.

"Our advertisers didn't think we could convince people to change their lifestyle," Jameson said. "We are showing people they don't have to change their lifestyle to be energy efficient."

She added, "Does it have to hurt to be efficient? No. Look at the numbers."

The Department of Energy figures that if just 20 percent of Americans would more regularly check to ensure tires are properly inflated, it would save 2.1 million gallons of gasoline a day. Ads promote that by showing an air pump with the headline, "Free gas at this pump."

If just 20 percent of Americans would begin riding in car pools or using mass transportation, Jameson said it would save 3.7 million gallons a day.

If just 20 percent of Americans would merely drive the speed limit or reduce usual speed by five miles an hour, it would save 2.1 million gallons a day.

If just 20 percent of Americans with more than one car would use the most efficient one more often, it would save 1.5 million gallons a day.

And if just 20 percent of Americans would use lower octane gasoline (which saves energy because higher octane fuel requires more energy to produce), it would save 2.7 million gallons a day.