Updated

U.S. gasoline prices (search) climbed another 3 cents per gallon in the past two weeks on the strength of high crude oil prices, tight capacity and soaring demand, an analyst said Sunday.

The nationwide average for all gasoline grades, including taxes, was nearly $1.86 per gallon on Friday, up 3.07 cents from April 9, according to the Lundberg Survey (search) of 8,000 stations nationwide.

The average price "has broken all-time record highs for two months straight," although it remained about $1 a gallon lower than the peak price of March 1981 when adjusted for inflation, Trilby Lundberg said.

Since Dec. 19, the average gas price has risen 34.55 cents, she added.

The latest increase was prompted by crude oil prices that have topped $36 per barrel coupled with OPEC (search) production cuts and a growth in crude oil demand, chiefly in the United States and China, Lundberg said.

She said the U.S. market prices are affected by growing gasoline demand — despite the higher prices — thanks to an improving economy, a tight refining capacity, and new federal rules for formulating less-polluting gasoline which add to the cost and make it harder to import foreign supplies that don't meet the new specifications.

Lundberg said it was impossible to know whether prices will continue to increase but "it seems more likely than not" as the peak summer travel season approaches.

The national weighted average price of gasoline, including taxes, at self-serve pumps Friday was about $1.83 for regular, $1.92 for mid-grade and $2.01 for premium.

Overall, California continued to have the highest average prices even though the average price for regular dipped a dime per gallon in the past two weeks.

There was a "sizable gap" between California supply and demand but Lundberg said that has shrunk as refineries which were shut down for maintenance and retooling to meet new formulation requirements came back online.

The average California prices were $2.12 per gallon for regular, $2.23 for mid-grade and $2.33 for premium, Lundberg said.

San Diego had the highest U.S. average price for self-serve regular, at $2.17 per gallon, down more than 5 cents in two weeks.