The average price for gas dropped about 4 cents since last Friday, the biggest weekly decline in about three months.
Analysts say motorists should see further declines through autumn. But they warn that the decreases will happen slowly because of ongoing supply issues in some regions of the country.
Auto club AAA says the national average fell about a penny overnight to $3.833 per gallon. That's still nearly 12 cents more than a month ago.
Meanwhile, oil rose slightly, but is still headed for its biggest weekly decline since late June. Traders are uncertain about the global economy and oil demand has weakened while supplies are plentiful. Benchmark oil rose 73 cents to $93.16 in New York.