The decline of more than 12 percent in crude oil prices last week shaved about 1 percent from prices at the pump as consumers paid less for gasoline and diesel fuel, the government said on Monday.
The national price for regular, self-service gasoline declined almost a nickel over the last week to $4.06 a gallon, according to the federal Energy Information Administration's survey of service stations.
The average pump price was still up $1.11 a gallon from a year ago, mirroring crude oil costs that remain far above historical levels.
This fall in fuel costs was due to the $16 per barrel decline in the price of crude oil, or about 12 percent.
Every $1 drop in the price for a barrel of oil results in a 2.4 cent decline in a gallon of gasoline, according to the EIA.
If crude oil stays down near $130 a barrel, pump prices are expected to keep falling over the next few weeks, the forecasting agency said.
But the EIA said refiners may not pass all the savings on to the pump and may take a bigger profit from making gasoline with cheaper crude.
In the agency's weekly survey, gasoline was the most expensive on the West Coast at $4.36 a gallon, down 5.2 cents.
Los Angeles had the highest big city price at $4.48, down 5.9 cents.
The Gulf Coast states had the lowest regional price at $3.94 a gallon, down 2.9 cents.
Houston had the lowest pump price, up a penny at $3.92.
The EIA also reported gasoline prices were down 5.7 cents at $4.46 in San Francisco, down 5 cents at $4.28 in Seattle, down 7.5 cent at $4.23 in Chicago, down 3.3 cents at $4.14 in New York City, down 4.8 cents at $4.13 in Miami, down 1.5 cents at $4 in Denver and down 10.6 cents at $3.92 in Cleveland.
Separately, the average price paid for diesel fuel fell 4.6 cents from last week's record to $4.72 a gallon, but still $1.83 higher from a year ago, the EIA said.
Both the New England and central Atlantic states had the most expensive diesel at $4.87 a gallon each, down 2 and 4.3 cents, respectively.
The Midwest had the cheapest fuel at $4.65, down almost a nickel.