SAN FRANCISCO (MarketWatch) — Fill’er up! The good times at the gas pump will continue to roll.

U.S. drivers paid the least for a gallon of gas in four years, and retail gasoline prices are likely to fall by another 15 cents to 20 cents nationwide by New Year’s Day, travel and leisure company AAA said Wednesday.

Gasoline futures in New York, meanwhile, settled at a five-year low on Wednesday after a government weekly supply report showed an unexpected uptick in gasoline stockpiles in the last week. Lower gasoline futures usually lag a week or two to translate into lower retail gasoline prices.

“Gas prices have fallen at a remarkable pace that would have been unthinkable just a few months ago,” said Avery Ash, a AAA spokesman. “Lower gas prices represent real doorbuster savings as everyone begins their holiday shopping.”

Gasoline futures were caught flat-footed Wednesday by an Energy Information Administration report showing gasoline supplies up by 2.1 million barrels in the week ended Nov. 28. Analysts surveyed by Platts had expected gasoline stockpiles to be unchanged in the week.

At gas stations, lower oil prices have provided a boon to U.S. drivers and to U.S. businesses. Wednesday’s national retail average price of $2.75 a gallon was the lowest average since Oct. 5, 2010, according to AAA.

Retail prices are about 52 cents cheaper than last year’s, and AAA estimated U.S. residents are saving about $200 million a day on gasoline compared with a year ago.

The average retail gas price has fallen about 95 cents since reaching a high of $3.70 in April.

These lower prices are due to lower oil futures prices. Oil has cratered in recent sessions, hitting a five-year low last week in the aftermath of a meeting of the Organization of the Petroleum Exporting Countries, where the group decided to keep its production unchanged.

Crude futures trading in New York ended Wednesday up modestly, but they have lost nearly 40% since a peak in June. Read Oil jumps after surprise U.S. supply decrease.

“Gas prices likely will remain relatively low this winter,” AAA said.