If the decline continues, it could buoy consumers, retailers, and carmakers.
For the first time since June 5, the average price of gasoline in the United States has fallen below $4 a gallon.
It hit $3.98 a gallon overnight for unleaded gas, according to GasPriceWatch.com, down 3 cents a gallon from Thursday.
The drop in gasoline prices mirrors a fall of about $20 a barrel in oil prices over the past two weeks. Economists believe if gasoline prices continue to fall it could give consumers a psychological boost. It could also help retailers and even the Detroit automobile companies.
"One of the first things the falling gasoline price does is potentially help consumer confidence," says Dennis Jacobe, the Washington-based chief economist at the Gallup polling company. "Even though prices are still high, if they are going in the right direction that helps a little bit."
Falling gasoline prices may also help bolster the stock market. In recent months stock prices have been under pressure as investors worried about the affect of high energy prices on the economy. If prices were to continue to fall, it might also help Detroit, which has large stockpiles of SUVs, as well as retailers, who are preparing for the back-to-school season.
"If parents start to see this drop in prices, it might give them an extra $20 to $30 toward their child's back-to-school expenses," says Kathy Grannis, a spokeswoman for the National Retail Federation in Washington.