The price of oil shot above $51 a barrel for the first time since late October on Tuesday, probably condemning motorists to another round of gasoline price increases.
The benchmark U.S. grade of crude oil for March delivery soared $2.80, or 5.8%, to $51.15 on the New York Mercantile Exchange. It was the commodity's biggest one-day percentage gain since June.
The jump rekindled fears of a slowdown in U.S. economic growth and helped depress the stock market.
Pump prices have been climbing in response to an earlier upswing in oil, which accounts for about half the retail price of each gallon of gasoline.
Seasonal maintenance at refineries, which crimps supplies as oil companies switch from winter to summer blends of fuel, also has helped lift prices at the pump.
The average price for self-serve regular in California rose this week for the fifth straight week, gaining an additional 5.9 cents to $2.15 a gallon, according to the Energy Department.
Now, with crude prices spurting higher again, "gasoline prices are on a trajectory that is going to take them above last year's highs," especially once the busy summer driving season begins, predicted Tom Kloza, chief oil analyst at the Oil Price Information Service, a company that tracks fuel prices.
Already, prices at some service stations in California are well above the $2.15 statewide average.
"I was shocked" to see regular selling for $2.519 at a Chevron in downtown Los Angeles, said Keith Mallett of La Mesa. But he added: "You've got to pay, so what can you do?"
Oil prices are trading at lofty levels because global supplies of crude are stretched thin, while the world's thirst for oil -- especially in the U.S. and China -- keeps climbing steadily.
The energy markets have been repeatedly roiled over the past year by various events, such as terrorism in the Middle East and political tensions in Russia, that posed a threat to those tight supplies.
Given those conditions, the energy markets recently had anticipated that oil might again surpass $50 a barrel. Yet the sudden surge Tuesday caught some analysts by surprise because it wasn't triggered by one major development.
"Fundamentally there was nothing we saw that could justify the move," said Steven Bellino, a senior vice president at Fimat USA Inc., a commodities brokerage in New York.
Traders returning from the three-day holiday weekend seized on several factors to bid prices higher not only for crude oil but also for gasoline and heating oil.
