In some parts of the U.S., gas is down to nearly $1 a gallon. But not in California. 
 
 The average price of regular gas in California is $2.50 a gallon, or about 80 cents higher than the national average. 
 
 Here's why. 
 
 California has one of the highest gas taxes in the country at about 40 cents a gallon -- roughly 10 cents more than the national average. 
 
 California also has tougher gas standards than those of the federal government and mandates the use of cleaner gas with fewer emissions. 
 
 Experts tout California gas as one of the cleanest-burning in the world, but the distinction doesn't come cheap. 
 
 It costs more to refine because it's a special oxygenated blend that meets California's strict air-quality rules. Refineries have to use a specialized process, and only a few refineries are able to make California-approved gas. 
 
 Related: Gas is near $1 a gallon in some places 
 
 That means the loss of a refinery can wreak havoc. An explosion last year at a major Exxon Mobil refinery in Torrance, California, put a crimp in the supply of gas. The facility is expected to come back online the middle of this year -- and that should help bring prices down closer to the national average. 
 
 "Right now California is a bit like Pluto revolving around the sun of crude oil. But it's going to move closer to the national average when that refinery reopens," Tom Kloza of the Oil Price Information Service said. 
 
 Kloza also noted that the wholesale cost of gas in California -- a bellwether of future prices at the pump -- finally dropped below $1 on Monday. (California was the last state to hit this milestone out of all 50 states.) 
 
 Still, California is doing something right. 
 
 "Criticize California all you want, but the air quality has improved dramatically over the last 20 years," Kloza said. "It has cleaned the air." ||||| The fall in average regular unleaded gasoline prices to about $2 a gallon has helped keep a lid on inflation. (Photo: AP) 
 
 Gasoline prices may soon dip below $1 per gallon at some stations in the Midwest, putting the price of unleaded fuel in the same category as a pack of gum or a bag of pretzels from the vending machine. 
 
 "The cheapest gasoline prices in over 12 years are showing up in some lucky states in the heart of the nation, with previously unthinkable 99-cent gasoline becoming a strong possibility as wholesale gas prices plunge amidst growing supply," GasBuddy.com senior analyst Patrick DeHaan said in an email. 
 
 Prices have plunged to 12-year lows in Michigan, Wisconsin, Illinois, Minnesota, North Dakota, Oklahoma, Indiana, Ohio and Kansas, according to GasBuddy. 
 
 To be sure, 99-cent gas "still will be isolated," DeHaan said — likely because of the highly regional nature of refining costs, oil inventories and shipping. 
 
 But the plunging price of gasoline is beginning to conjure nostalgic 20th Century memories of rock-bottom fill-ups at the corner station, where lollipops and licorice were also prized commodities. 
 
 For U.S. consumers, it's fantastic news, providing instant savings — particularly for low-income consumers for whom gas represents a high percentage of their budget. 
 
 The nationwide average is $1.721 per gallon as of 1:15 p.m., down 6.8 cents from a week ago, 25.6 cents from a month ago and 45.5 cents from a year ago. 
 
 But for oil companies, it's a mess, fueled principally by the global surplus in oil production. 
 
 The benchmark U.S. crude oil, known as West Texas Intermediate (WTI), fell 3.2% in mid-day trading to $28.75. The global benchmark, Brent crude, fell 5.2% to $31.16. Both commodities traded below $30 simultaneously at one point in January, reaching lows not seen since 2003. 
 
 The stocks of Chevron, BP and Exxon Mobil slipped 4%, 3.3% and 1.8%, respectively, in afternoon trading Tuesday. 
 
 An International Energy Agency report released Tuesday projected a downturn in global oil demand growth in 2016 from a five-year high of 1.5 million barrels per day in 2015 to 1.2 million barrels per day, primarily because of economic sluggishness in Europe, China and the U.S. 
 
 Lower demand could exacerbate low prices. Compounding matters is that the Organization of the Petroleum Exporting Countries (OPEC) increased production in January by 280,000 barrels per day to 32.6 million. 
 
 "A sanctions-free Iran, Saudi Arabia and Iraq all turned up the taps," IEA reported. 
 
 Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey. 
 
 Read or Share this story: http://usat.ly/1XguKJi ||||| Gas prices in at least nine states have fallen to their lowest levels in a dozen years, with some even approaching $1 a gallon in the Midwest. 
 
 Gas prices in Texas, Missouri, Ohio, Indiana, Illinois, Michigan, Oklahoma, Kansas, and North Dakota have reached their lowest average point since 2004, according to Gasbuddy.com . Oklahoma has the cheapest average cost of the bunch, at $1.37 for a gallon of regular, while North Dakota has the "highest" price point of the nine states, with an average that's still dirt cheap, all things considered: $1.63. 
 
 Even better, there are also at least eight states where some stations are peddling fuel for less than $1.25 a gallon, CNN Money reported . With gas priced at $1.11 a gallon at one 7-Eleven location, Oklahoma City currently hosts the cheapest gas in the country. (More than a dozen other stations in that city sell fuel for $1.14 or less.) 
 
 "Incredible as it sounds, we wouldn’t be shocked to see a few stations in these states as low as 99 cents a gallon," said Patrick DeHaan, senior petroleum analyst at Gasbuddy.com. 
 
 An oversupply of gas—due to factors such as increased U.S. production and a halting of sanctions on Iran—is saturating the market and bringing down prices at the pump. The average price of a gallon of regular gas in the U.S. is now $1.74, the cheapest since January 2009. Roughly one out of four gas stations in the country is now selling fuel for $1.50 or less per gallon. According to AAA , the national average for a gallon of regular is currently 44 cents cheaper than it was one year ago at this time. 
 
 But don't expect the bargain fuel prices to last forever, even if oil prices continue to plummet. Since oil refineries aren't profiting off this market, some may take the unfavorable conditions as a chance to shut down and conduct maintenance, Tom Kloza, chief analyst for the Oil Price Information Service, told CNN Money. The decreased supply of gas is expected to drive prices up again.
– You're not imagining things: Gas prices could soon fall as low as $1 per gallon at some US gas stations, USA Today reports. Some Midwest states—Michigan, Wisconsin, Illinois, Minnesota, North Dakota, Oklahoma, Indiana, Ohio, and Kansas—are already seeing the lowest prices in 12 years. And one in four US gas stations is currently selling gas for $1.50 per gallon or less, according to Time. “Incredible as it sounds, we wouldn’t be shocked to see a few stations in these states as low as 99 cents a gallon,” says one expert. As of Tuesday afternoon, the nationwide average was $1.72 per gallon. That's approximately 7 cents less than last week, 26 cents less than last month, and 46 cents less than last year. It's the lowest average price the US has seen in six years. The low prices—caused by a combination of falling demand and increasing production in the US and Middle East—are good news for consumers but bad news for oil companies. Oil prices hit 13-year lows last month, and the stocks of companies like BP and Exxon Mobil were down Tuesday. But not everyone is enjoying the savings. CNN reports the average price of gas in California is around $2.50 per gallon. That's due to both a larger-than-average gas tax and cleaner-than-average gasoline. California's requirement for gasoline that creates fewer emissions keeps prices higher but has made a huge impact on the state's air quality. One expert warns the rest of the country better enjoy low gas prices while it can. Refineries not turning a profit at these prices may close down for maintenance, sending gas supplies down and prices up.