CAMARILLO, Calif. (AP) — The average U.S. price of a gallon of gasoline has dropped six cents over the past two weeks. It’s the first decrease in gas prices since late December.

The Lundberg Survey of fuel prices released Sunday says the price of a gallon of regular is $3.74. Midgrade costs an average of $3.91 a gallon, and premium is $4.04.

Diesel was down four cents to $4.13 gallon.

Of the cities surveyed in the lower 48 states, Billings, Mont., has the nation’s lowest average price for gas at $3.31. Los Angeles has the highest at $4.23.

In California, the lowest average price was $4.02 in Sacramento. The average statewide for a gallon of regular was $4.15, down three cents.

Copyright 2013 The Associated Press.