The average price of gasoline has dropped 7 cents over the past three weeks to $2.22 a gallon for regular grade.
Industry analyst Trilby Lundberg said Sunday lower oil prices and an abundant gasoline supply caused the decline. She says the price is 60 cents less than it was a year ago.
The Lundberg Survey found the average price of midgrade unleaded is $2.51 a gallon and $2.72 for premium.
The highest average price for regular gasoline in the Lower 48 is $2.83 a gallon in the San Francisco Bay Area. The lowest is $1.81 in Charleston, South Carolina.
The U.S. average diesel price is $2.39 per gallon, down three cents from two weeks ago.