Fill her up! Gas prices drop before Labor Day weekend

LOS ANGELES, CA - JULY 16: A man pumps gas at a 76 gas station on July 16, 2013 in Los Angeles, California. Higher gas prices have spurred a 0.5 perce...
Gas prices have dropped 4 cents per gallon in the last two weeks due to plentiful supplies. The average price is $3.56 -- 20 cents lower than a year ago, according to the Lundberg Survey. Kevork Djansezian

Just in time for the Labor Day weekend -- gas prices have fallen again.

The average price for a gallon of gasoline slipped in the last two weeks, losing almost 4 cents due to abundant supplies, according to the Lundberg survey.

Gasoline cost $3.5596 per gallon on average on Aug. 23, down from $3.5895 on Aug. 9, based on a survey of about 2,500 retail stations in the 48 contiguous states. The average price per gallon had slipped 8 cents per gallon in the previous two-week period and is now 20 cents lower than a year ago.

Trilby Lundberg, editor of the Lundberg survey, said the drop in gasoline prices was due to increased supply of the motor fuel as U.S. refiners kept production capacity high.

"There's ample supply of gasoline," she said.

(Read more: AAA: Public less worried about dangerous driving)

The most expensive gasoline in the states surveyed was found in Long Island, New York, and San Diego, California, at $3.89 per gallon, while the cheapest was found in Charleston, South Carolina, where it cost $3.22 per gallon.

On Friday, crude oil futures traded in New York rose 1.4 percent to settle at $106.42 per barrel.

(Read more: Believe it or not, Americans are driving less)

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