CAMARILLO, Calif. (AP) — The average U.S. price of a gallon of gasoline has dropped six cents over the past two weeks.

The Lundberg Survey of fuel prices released Sunday says the price of a gallon of regular is $3.65. Midgrade costs an average of $3.82 a gallon, and premium is $3.96.

Diesel was down two pennies to $4.05 gallon.

Of the cities surveyed in the lower 48 states, Billings, Mont., has the nation's lowest average price for gas at $3.33. Chicago has the highest at $4.05.

In California, the lowest average price was $3.86 in Sacramento. The highest was in San Francisco at $4.03. The average statewide for a gallon of regular was $3.99, down four cents.

Check out CBS13's Pump Patrol to find the cheapest gas.

Copyright 2013 The Associated Press.