Cheap gaso­line. It's back.

Minnesota's av­er­age price for un­lead­ed regu­lar gaso­line dropped be­low $3 this week, ac­cord­ing to pric­ing ser­vices GasBuddy.com and the AAA Daily Fuel Gauge Report.

"It is a whale of a deal — it is like it's on sale," said Todd Brazman of St. Paul as he pumped a tank­ful of $2.89-per-gal­lon gaso­line Tues­day morn­ing into his pickup truck at Capitol City Station in St. Paul.

In­side the ad­ja­cent re­tail store, a smil­ing own­er, Todd Knudten, said his pre­pay pol­icy for cash cus­tom­ers is hav­ing an un­u­su­al side ef­fect.

"Peo­ple are pay­ing what they typ­i­cal­ly pay and hav­ing to come back in for change," he said.

Gaso­line prices across the na­tion have fallen as world oil prices have dropped to the low­est lev­els in years.

Minnesota is one of 10 states where regu­lar unlead­ed is sell­ing at or under $3 per gal­lon, ac­cord­ing to GasBuddy.com, which uses crowdsourcing to col­lect U.S. gaso­line prices. Minnesota gas prices are down 29 cents compared with the September average, according to GasBuddy.

This week is the first time since late December 2013 that Minnesota's average unleaded regular price has dropped below $3.

On Tuesday, prices dipped below $2.90 at a handful of stations around the metro, including Food & Fuel in Minneapolis on Central (2.85), Costco in Maple Grove ($2.84) and Clark in Inver Grove Heights ($2.85).

At Jensen's Care Care on Penn Avenue S. in Minneapolis, Ben Premack pumped gas into his car beneath a neon sign that read $2.98.

The Marathon-brand station dropped the price below $3 on Monday, said employee Kaehn Hale.

Premack didn't get the sub-$3 price because his car requires more expensive premium fuel. Even so, he said, "I will take any savings I can get."

Al­though the East and West coasts are still see­ing $3.50 gaso­line, the av­er­age price nationwide was $3.18 per gal­lon on Tues­day.

GasBuddy's chief oil an­a­lyst, Tom Kloza, has been predicting that gas prices would drop dra­mat­i­cal­ly this fall. He said in an inter­view Tues­day that it has hap­pened rap­id­ly, and may not be over.

"It's oc­cur­red quick­er than we thought it would," Kloza said. "If you ask the ques­tion, 'Are we near the bot­tom?' the an­swer is a big resounding no at the mo­ment."

Crude oil down

The benchmark world oil price slumped to its lowest level in four years on Tuesday, settling at just over $85 per barrel, down about 30 percent from four months ago.

The decline is driven by weaker oil demand worldwide and a decision by OPEC countries to maintain output and sell into the glutted, lower-priced market, according to Bloomberg.

Midwest refineries, including two in the Twin Cities area that supply much of Minnesota, are usually able to purchase crude oil at lower-than-world prices from North Dakota and Canada. North Dakota light sweet crude was priced at $70.25 per barrel in the most recent Oct. 9 Flint Hills Resources bulletin, down from $75.50 per barrel a week earlier, and from $78.46 per barrel in August.

Those slumping oil prices could mean lower profits in North Dakota, but the drop has not yet reached the point of no returns for most drillers. According to the North Dakota Division of Mineral Resources, drillers in the four most active North Dakota counties can break even at crude oil prices ranging from $28 per barrel to $42 per barrel.

Gasoline isn't the only fuel that's dropped in price. Kloza said jet fuel, diesel and heating oil also are benefiting from low crude oil prices.

Ethanol also is cheap right now, thanks to low corn prices and increased output from reopened plants, including two this year in Minnesota. The price doesn't have a big effect at the pump because most gasoline contains only 10 percent ethanol.

Yet low ethanol prices are evident at stations selling the highest ethanol blend E85, which is 85 percent ethanol and can be used only in flex fuel vehicles. On Tuesday, E85 was selling for as low as $2.05 per gallon in Minnesota, according to E85prices.com.

Staff writer John Ewoldt contributed to this report.

david.shaffer@startribune.com • 612-673-7090