The average U.S. price of gasoline has fallen 4 cents a gallon over the past two weeks and 20 cents since this time last year.
The Lundberg Survey of gas prices released Sunday reports that a gallon of regular now costs $3.56. Midgrade costs an average of $3.74 and premium is $3.88.
Of the cities surveyed in the Lower 48 states, Charleston, S.C., has the nation's lowest average price for regular at $3.22. The Long Island, New York, region has the highest at $3.82.
In California, the lowest average is Sacramento's $3.63.
The highest is San Diego's $3.82.
Rounded off, San Diego's price is the same as Long Island's. But analyst Trilby Lundberg says the California city's is actually a few percentage points of a penny less.