Most major automakers raced past expectations for U.S. sales in March as buyers flocked to smaller, more fuel-efficient cars in response to rising gasoline prices at the pump.

Executives at General Motors Co. and Ford Motor Co., which reported sales gains of 11.4 percent and 19 percent, respectively, also said they did not see the Japan crisis biting into sales in the near term.

The strong sales, combined with the Labor Department’s report about solid U.S. job growth last month, boosted hopes that consumers will have more money in their wallets and feel confident enough to buy more cars and trucks, investors said.

“When I look at the overall picture, I say ‘Hey, this recovery’s intact. It’s still going strong in the U.S.,’ ” said Gary Bradshaw, a portfolio manager with Hodges Capital Management, which owns Ford shares. “More people going back to work, they can afford cars.”

GM shares closed up 4.4 percent on the New York Stock Exchange on Friday, while Ford gained 1.6 percent.

Auto sales represent one of the first snapshots every month of U.S. consumer demand, and 34 economists surveyed by Reuters estimated March sales would rise 12 percent on average.

The stronger-than-expected results at many automakers echoed the good news on the labor front as U.S. employment on Friday recorded a second straight month of solid gains in March and the jobless rate fell to a two-year low of 8.8 percent.

GM sales chief Don Johnson does not expect a “significant” impact from the Japan disruptions on sales at this time, while Ford said any fluctuations in manufacturing caused by last month’s Japan earthquake, tsunami and resulting nuclear crisis will not upset demand.

“The developments should not derail the recovery in the U.S.,” Ford senior U.S. economist Jenny Lin said.

However, a Ford executive also warned that the company’s inventory of small cars has been “pinched” by the heavy demand, and other automakers are likely seeing the same thing.

GM and Ford executives said they expect U.S. sales this year to total  13 million to 13.5 million, up from 11.5 million last year.

However, some still worry that the rising gasoline prices and the uncertainty caused by events in Japan could still hurt sales in April and May.

“The recovery is fragile,” Edmunds.com analyst Michelle Krebs said, adding that sales in March weakened later in the month as gasoline prices rose. “The consumer does not like uncertainty, and they had a heavy dose of it in March.”

GM said total U.S. sales in March for its four brands rose 11.4 percent from last year to 206,621 vehicles. Including its four former brands — Hummer, Pontiac, Saab and Saturn — GM sales rose 9.6 percent.

Edmunds had expected a gain of 11 percent including the former brands, and TrueCar.com and JP Morgan also said the results missed expectations.

GM’s incentives per vehicle on average were $600 to $800 lower last month than February, and the automaker would be prudent and disciplined with its deals going forward, Johnson said.

Ford, Chrysler Group LLC and Nissan Motor Co. all reported stronger-than-expected results and Ford outsold GM for only the second time since 1998.

Chrysler sales jumped 31 percent, while Nissan’s rose 28.4 percent. Sales at Hyundai Motor Co., Honda Motor Co. and Daimler AG’s Mercedes brand rose 32 percent, 18.9 percent and 12.6 percent, respectively.

Sales at Toyota Motor Corp., which has been affected heavily by the Japan crisis, fell 9.2 percent.

However, light trucks, which include pickup trucks and sport utility vehicles, make up a little more than half of U.S. auto sales and account for a disproportionate share of profits at the U.S. automakers because of their higher prices.

“With gasoline prices eclipsing $3.50 a gallon, consumers are placing a high priority on fuel efficiency in every size and kind of vehicle,” said Ken Czubay, Ford’s vice president of U.S. sales.

Gasoline prices rose more than 3 cents, to $3.60, a gallon over the last week, the Energy Department said. The average price of regular gas is 80 cents higher than a year ago as conflict in Libya and rising tensions in the Middle East have sent the cost of crude oil to above $100 a barrel.

Another focus is the aftermath of the Japanese earthquake and subsequent tsunami last month which caused many supplier plants there to close or cope with power outages.

Industry executives said they are monitoring the situation closely, but have declined to speculate on its impact. GM’s Johnson said the U.S. automaker has a “very good” level of vehicle inventory going into April.

Ford said it is pursuing other sources of supply for affected parts as necessary, but was able to maintain its previously announced first-quarter production plans.

However, the U.S. automaker warned that further problems in Japan in the weeks ahead could force it to reduce or idle output, including suspending output at a truck plant in Kentucky next week. It is suspending production next week at a plant in Flat Rock, Michigan, which builds Ford Mustang cars, due to weaker demand.

Nissan said it was shifting non-production days scheduled for later in the second and in the third quarters to April.