The average price of a gallon of regular-grade gasoline dropped 7 cents nationally over the past two weeks, to $2.32.

Industry analyst Trilby Lundberg of the Lundberg Survey said Sunday that the drop reflects lower costs for crude oil.

She says the national average is 4 cents a gallon below the price a year ago.

Gas in San Francisco was the highest in the contiguous United States at an average of $3.06 a gallon. The lowest was in Charleston, South Carolina, at $1.91 a gallon.

The U.S. average diesel price is $2.53, down 3 cents from two weeks ago.

(AP)