WILMINGTON, Del. — General Motors Corp. officially blew up its old business model yesterday, closing four pickup truck and sport utility vehicle factories, announcing a new small car that could get 45 miles per gallon and shedding 8,350 jobs in the process.

Now the world's largest automaker by sales needs to figure out how it can sell enough cars to make money in a shrinking U.S. market.

The automaker said it will idle pickup and SUV factories in Janesville, Wis.; Oshawa, Ontario; Moraine, Ohio; and Toluca, Mexico, as it tries to deal with a consumer shift to smaller vehicles brought on by $4-a-gallon gasoline. GM also said its Hummer brand, one of the largest vehicles on U.S. highways, will either be sold or get a remake.

The national average price of a gallon of regular hit a record $3.978 yesterday, with Hawai'i and 12 other states reporting gas above $4 a gallon, according to the AAA Daily Fuel Gauge Report. In a recent survey of AAA members in Hawai'i, 21 percent said they are responding to higher gas prices by driving vehicles that are more fuel-efficient.

GM said the truck plant cuts, which will reduce its production capacity for pickups and large SUVs by about 35 percent, will save it $1 billion a year, and when combined with earlier measures, by 2011 will save $15 billion over 2005 costs.

GM's moves, which come after a series of restructuring measures since 2005, are the result of a huge shift in U.S. consumer preferences toward small cars and crossovers in the past two months.

"We at GM don't think this is a spike or temporary shift," chief executive Rick Wagoner said. "We believe that it is, by and large, permanent."

The automaker now will have to try to parlay its strong overseas sales and lower North American costs into a profit by selling cars in the $15,000 to $20,000 range, half the price of its high-profit SUVs and pickups.

"The new cars ... tend to make money, just not as much money compared to the nice margins on the SUVs and large trucks," said Pete Hastings, a senior analyst at Memphis.-based Morgan Keegan & Co.

"I don't think they can get to profitability quickly if the economy stays where it is," he added.

GM lost $3.3 billion in the first quarter and burned through $3.4 billion in cash from January through March. Its May sales were down 28 percent compared with last May.

The pace of the cash burn may force GM back to the capital markets for more borrowing, Hastings said.

"They've got a lot of liquidity now," Hastings said. "They are burning through it faster than they thought they would earlier in the year."

Just before the annual shareholders' meeting, Wagoner also announced that the automaker will build a new-generation small car starting in mid-2010 at a factory in Lordstown, Ohio, that now makes the Chevrolet Cobalt. GM said that with a manual transmission, the new model will get up to 45 mpg on the highway.

In the past, costs generally were too high for Detroit automakers to turn a profit on small U.S.-built cars. But Wagoner said GM has lowered costs enough with new labor contracts and other measures to turn a profit.

"The direct answer is we need to," Wagoner told reporters. "We believe we can build a car there profitably."

Wagoner also announced that the board has approved production of the Chevrolet Volt plug-in electric car, expected in showrooms by the end of 2010. Fully charged, the Volt could drive about 40 miles without any gasoline, and a small conventional engine would recharge the vehicle, allowing it to get the equivalent of 150 miles per gallon.