The national average gas price fell about 5 cents to $3.57 a gallon for regular, the third consecutive weekly decrease, as refinery inventories rise.
The Energy Department's U.S. Energy Information Administration said the national average weekly gas price is still 14 cents higher than it was a year ago.
Prices fell in all the regions it tracks except the Central Atlantic, where gas prices increased by about 1 cent, and the West Coast, where it increased by 6 cents.
Patrick DeHaan, senior petroleum analyst with GasBuddy, said higher refinery production, or rising inventories, have been driving prices lower, "especially after earlier refining spats have cleared up and production has resumed at the affected facilities."
Most notably, prices in the Great Lakes have fallen sharply, DeHaan said.
Vacationers who will hit the road over the Fourth of July can look forward to a cheaper vacation if the price drop continues.
DeHaan said he expected the national average to be around $3.50 over the July 4 weekend.
Even though prices are still higher than they were last year, Americans don't seem to be holding themselves back at the pump.
"Sadly, Americans are becoming used to these prices and they are no longer shocking," DeHaan said.
The Environmental Protection Agency offered some tips to drive more efficiently:
1. Drive sensibly.
Aggressive driving (speeding, rapid acceleration and braking) wastes gas and can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town, the EPA said.
2. Observe the speed limit.
While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 50 mph. The EPA said you can assume that each 5 mph you drive over 50 mph is like paying an additional $0.25 per gallon for gas.
3. Remove excess weight.
An extra 100 pounds in your vehicle could reduce your MPG by up to 2 percent based on the percentage of extra weight relative to the vehicle's weight and affects smaller vehicles more than larger ones, the EPA said.
4. Avoid excessive idling.
Idling can use a quarter to a half gallon of fuel per hour, depending on engine size and air conditioner (AC) use. The EPA advises drivers to turn off your engine when your vehicle is parked.
5. Use cruise control.
Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas, the EPA said.
6. Use overdrive gears.
When you use overdrive gearing, your car's engine speed goes down, which saves gas and reduces engine wear, the agency said.
ABC News' Alana Abramson contributed to this report.