William Kolodner pulled his shiny silver-green car up to the pump at the St. Paul Street BP station and committed what some purists would consider Jaguar abuse.
The Baltimore lawyer bypassed the $2.87-a-gallon high-test and pumped midgrade Amoco Silver gasoline - with a paltry 89 octane level and a $2.78 price - into a car whose manufacturer recommends Supreme fuel with octane of at least 92.
"There's absolutely no difference in how the car operates. The real question is, should I trade further down?" Kolodner said.
That's a question motorists - even those well-heeled enough to drive Jaguars - have been asking around the country as prices at the pump have soared by more than 70 percent in the past year.
Many of them have decided that the answer is to buy regular 87 octane gas no matter what their car's maker says is "recommended" or - in some cases - "required." Kolodner said he's been putting midgrade gas into his 1996 Jaguar Vanden Plas for the past six months because of high gas prices. Now he defies the manufacturer's dictates and uses 89 octane gas in his Lexus, too.
Kolodner's trading down reflects a long-term trend and short-term market forces. Regular gas, which accounted for 70 percent of sales in 1994, captured more than 86 percent of the market last year, according to the federal Energy Information Administration. This year, sales of regular have increased by almost 5 percent while midgrade and premium (91 octane and up) sales have fallen more than 3 percent.
Jeff Dolch, owner of the station at St. Paul Street and Mount Royal Avenue where Kolodner pumped his gas, said he's seen a big drop-off in premium gasoline sales within the past few months. At his station this week, the spread between the price of regular and premium was 18 cents - less than the prevailing national differential of about 25 cents.
Dolch said that until recently he would have sold about 13,000 to 14,000 gallons of 93 octane high-test by this time of the month. Last month, that sank to 12,000 gallons, and this month it stands at 11,000, he said. Meanwhile his sales of regular are up.
So does that mean local mechanics can expect a spike in business in a few months as octane-starved high-performance engines sputter and wheeze into service bays?
Not likely, says Jim Spires, general manager of Hillmuth Certified Automotive, an independent, family-owned shop in Clarksville.
"There's no harm done. The reason for the premium gasoline is simply to get better performance," he said.
And except for a few who are persnickety about performance, Spires said, drivers wouldn't notice a difference in the ride of a luxury vehicle running on regular gasoline.
David Cole, chairman of the Center for Automotive Research, drew a distinction between a manufacturer's recommendation and a requirement.
"If it isn't mandatory in an owner's manual, I think people are basically wasting money when they use premium fuel," said Cole, whose center is an independent spinoff from the University of Michigan. "If it says it's mandatory, then you'd better stick with the premium grade of gasoline."
Internet postings show that some owners of luxury vehicles worry that if they use lower-octane gas, the engine could be damaged and the manufacturer could void the warranty.
Robert Moran, a spokesman for Mercedes Benz USA, says that his company "requires" the use of premium gasoline and that he believes most customers comply. He said he knows of no cases where a warranty has been voided over fuel use.
"From a customer standpoint, as far as we're concerned, it's not really an issue," he said.
Shane Ewing, service manager at Laurel Jaguar, said many of his customers have traded down to lower-octane fuel grades because of rising costs. He said he's seen a "minimal" number of cases where that might have caused fuel-injector problems.
"It's been unusual that I've seen evidence of lower-octane fuels causing problems with the car's running," he said.
John Cogan, spokesman for the Energy Information Administration, said many motorists have misconceptions about premium gasoline.
"Premium's not cleaner than regular gasoline. Premium doesn't have more energy contained in it than regular gasoline," he said. All it means, he said, is that it contains more octane, a chemical that prevents premature ignition.
One point on which most authorities agree is that putting premium or midgrade gasoline into the vast majority of cars and light trucks that are built to run on regular is a nondeductible charitable contribution to the oil industry.
"If you're driving a Honda Civic and you insist on putting a premium gas into it, it's still going to be a Honda Civic. It's not going to turn into a Viper," Spires said, referring to the ultra-high-performance sports car from Dodge.
Despite rising prices and advice to the contrary from such sources as the federal government and Click and Clack of public radio's Car Talk, a belief persists among some motorists that premium gasoline can improve the performance, extend the working life and improve the mileage of any car.
Postings on many car-related Web sites show that some motorists have an almost religious devotion to high-octane gasoline, worrying that even occasional use of "the cheap stuff" could ruin their engines.
"I'd be willing to bet that there's a lot of urban legends that have been passed on from generation to generation," said Ed Kriston, an Approved Auto Repair specialist for AAA Mid-Atlantic.
Some motorists said they had been told by mechanics that they should periodically buy a tank of premium - even though their cars were built to use regular - to keep the engine free of deposits.
Cole, of the Center for Automotive Research, said that is a "myth" and that the detergents in regular gasoline are sufficient to keep an engine clean. "One of the greatest purveyors of these myths is mechanics," he said.
Cole said that before the 1970s, when the use of leaded gasoline was phased out, many more cars needed premium gas to control engine knocking.
"That era has been gone for many years," he said, noting that modern cars have electronic "knock sensors" that adjust engines to account for the fuel grade.
Cole said that cars with high-compression engines might get better fuel efficiency with premium than with regular but probably not enough to offset the higher cost.
"If everybody used what made the best sense for them, I think the use of premium gas would diminish quite greatly," he said.
Some people have excellent reasons for pumping high-test.
Legal assistant Avon E. Tripps, who stopped by the St. Paul Street BP this week to fuel an Infiniti QX 4 SUV with its manufacturer-recommended premium gas, wouldn't consider jeopardizing the performance of a vehicle his prestigious law firm uses to transport clients. And he doesn't blink a eye at the $40-$45 it takes to fill the tank.
"They pay for the gasoline, so it doesn't come out of my pocket," he said.
What are octane ratings?
Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature iggition of the compressed fuel-air mixture in one or more cylinders.
Is all "premium" or "regular" gasoline the same?
The octane rating of gasoline marked "premium" or "regular" is not consistent across the country. One state may require a minimum octane rating of 92 for all premium gasoline, while another may allow 90 octane to be called premium. To make sure you know what you're buying, check the octane rating on the yellow sticker on the gas pump instead of relying on the name "premium" or "regular."