AP Photo/Michael Conroy
A Swifty gas station in Kokomo, Ind., advertises a discount for cast as gas sold for $3.17 in Kokomo, Ind., Thursday, Oct. 24, 2013. Local gasoline prices are swinging up and down ever more drastically, a result of a national fuel system that is operating with a shrinking margin for error.
Gas prices are dropping across most of the country — with 15 percent of stations selling it for less than $3 a gallon — but volatility is making it hard for many drivers to celebrate.
Swings of 20 cents a gallon or more in a day are happening more often, at a rate not seen since 2008, according an Associated Press analysis of data collected by GasBuddy.com.
"The lack of consistency makes it hard for people to plan," said Michael Green, a spokesman for the AAA. "If Starbucks changed the price of coffee every day, people would be angry about that, as well."
The problem is that refiners have lowered the amount of fuel they keep on hand, and short-term disturbances — like a storm or fire that throws a refinery off line — have an immediate impact.
For instance, construction at BP's Whiting Refinery in Northwest Indiana kept output down in the first half of the year. The result? Gas prices in Kokomo, Ind., regularly fluctuate 10 or 20 cents in a single day, the AP found.
"If I don't have to buy gas in Kokomo, I don't," Jim Brooks, who works at a Chrysler transmission plant in town, said recently as he bought soda and chips — but no fuel — at a filling station.
The good news is that on the whole, prices are on the downswing. The national average of $3.25 a gallon could sink to $3.10 by the end of the year, Green said.
"Ten or more states could see average prices below $3 per gallon by the end of the year," he said.
Missouri's average was $2.91 at the start of this week, but Arkansas and Texas were flirting with the threshold at $3 and $3.01, respectively.
Prices follow a seasonal cycle: highest in the summer when demand spikes and supply is low because of spring repairs to refineries, and lowest in winter when people cut back on driving.
At the moment, supply is 7% higher than it was a year ago, the AAA said.
Green attributes that, in part, to production increases at many refineries to handle growing North American oil production. There have been fewer major outages. And Mother Nature is cooperating: There hasn't been a major hurricane this season playing havoc with supply.
Even with prices generally low, though, many consumers are unsettled by the variations at the pump.
Mike Barnett, who spends about $250 a day on fuel for his small business in Kokomo, puts just a quarter or half a tank of gas in his vans and trucks when the price gets high and then waits for a better deal to fill up.
"You just can't come and get gas like you used to," he said.
The Associated Press contributed to this report.