The average U.S. price of a gallon of gasoline has fallen about 8 cents over the past two weeks.

The Lundberg Survey of gas prices released Sunday says the price of a gallon of regular is $3.60. Midgrade costs an average of $3.78 a gallon, and premium is $3.92.

Lundberg Survey President Trilby Lundberg says refiners are over-producing gasoline and slashing their wholesale prices to move product.

Of the cities surveyed in the Lower 48 states, Charleston, S.C., has the nation’s lowest average price for regular gasoline at $3.27 a gallon. Chicago and San Diego have the highest average price at $3.92.

The lowest average price in California is $3.72 in Sacramento. The average statewide for a gallon of regular is $3.86, down 11 cents from two weeks ago.

(AP)