Posted on: Sunday, May 23, 2004

The only thing premium may be price

By Jeff Plungis
Detroit News

WASHINGTON — If you're one of those consumers who puts a premium on high-quality gasoline, you might be getting hosed.

Premium blends of gasoline guarantee higher octane ratings. But there is an extra cost for the higher energy content, and experts say in most cases it's not worth it.

Motorists nationwide can expect to spend an average of $2.19 a gallon on premium this week, compared with $2.02 for regular unleaded, according to the federal Energy Information Administration. (According to the AAA travel club survey posted Thursday, premium in Hawai'i averaged $2.447 a gallon compared to $2.272 for regular.)

Some motorists buy better blends under the belief that better gas will deliver better performance. Oil companies have advertised that premium blends are better on the engine.

Experts say these are two of the most common myths about premium gasoline. And one way to save money at the pump is to switch to a lower grade.

"Unless it specifically says it is required in your owners' manual, you don't need it," said Jim Rink, spokesman for AAA Michigan.

Some models have high-performance engines specifically designed for high-octane fuels, typically luxury models or sports cars. If you own a car like this, the owner's manual and the sticker on your fuel tank door will clearly spell it out.

But even these cars can often run on regular gasoline, with just a marginal loss of performance.

The difference between grades of gasoline is posted on the pump. Regular generally has an octane rating of 87, mid-grade 89 and premium 93. A higher-octane fuel will combust more completely in the engine.

The rule of thumb to knowing whether you are not using high enough octane is listening to your engine. If it knocks or pings while it is running, you need to switch to a higher grade of gas.

Jim Williams, a senior manager at the American Petroleum Institute in Washington, advises consumers to try regular grades of gasoline and monitor their engine's performance.

"I'd start with the regular," Williams said. "If it doesn't knock, that's what I'd use."

Williams said he would try mid-grade gas and check for knocks before trading up to premium. He said he uses a mix of regular and premium in his own car in which premium is recommended.

But Brian Moody, road test editor for Edmunds.com, an online car-buying guide, cautions that there is a long-term risk to wearing out some engine components, like the catalytic converter, by using too low a grade of gasoline.