The current

Downgrading gasoline

As the price of fuel continues to climb, more drivers are trying to save 20 or so cents a gallon by using regular or midgrade gasoline, even when their owner's manuals recommend premium.

For gas station managers, fuel suppliers and motorists across the country, the run on the cheaper fuel has led to more uncertainty at the pumps, as some stations have run out of the cheaper grades.

"Even people with the high-end cars are cutting corners and using the cheaper stuff," said Dominick Vallera, manager of a Shell station in Hartford, Conn. "It's got us constantly guessing how much to order."

For nearly 48 hours last week, Vallera had to put yellow bags on regular gas pump handles because he had run dry.

Brian Alterio said he visited three stations one day last week in New York City before finding one with regular gasoline left to fill his 2004 Acura.

Even though the car's manual says he should use premium, Alterio, 59, said the occasional pinging from his engine, caused by using the lower-octane gasoline, is worth the savings.

Automotive experts say following the manufacturer's instructions is advisable, and some high-performance cars when accelerating can experience knocking and hesitation -- and possibly some engine damage -- if regular is used when a higher grade is recommended.

The shift toward regular and midgrade gasoline is part of a longer-term move away from higher-grade fuel.

In 2007, premium accounted for 9.4 percent of all gasoline sales in the nation, down from 16.6 percent 10 years ago.

Jeff Lenard, a spokesman for the National Association of Convenience Stores, said the biggest shift over the last year had been from premium to midgrade.

"The only thing I've noticed is more money in my wallet," said Steve Altman, standing alongside a black 2007 Mercedes-Benz in Arlington, Va.