NEW YORK (REUTERS) - The average price of a gallon of gasoline in the United States fell 25 US cents in the past two weeks, tumbling to its lowest level in more than five-and-a-half years, according to the Lundberg survey released Sunday.

Prices for regular-grade petrol fell to US$2.47 a gallon (86 Singapore cents per litre) in the survey dated Dec 19, down 25 US cents since the previous survey on Dec 5.

The recent drop has taken prices down more than US$1.25 a gallon since a recent peak in May of this year.

"This is mostly driven by crude oil prices, and absent a sudden spike we very well may see a drop of a few pennies more,"said the survey's publisher, Trilby Lundberg. "That said, demand is up at these low prices."

US crude futures have been sharply weaker of late, dropping for four straight weeks, as well as in 11 of the past 12 weeks. Crude prices fell 14.2 per cent over the past two weeks, though they rose 5.1 per cent on Friday, settling at US$57.13 per barrel.

The highest price within the survey area in 48 US states was recorded in Long Island at US$2.82 per gallon, with the lowest in Tulsa, at US$2.06 per gallon.