Does premium gas have the kick it claims, or is it a big waste of money?
Charles Brown bought his Nissan Maxima in 1999. The car's manual recommended that he use only premium gasoline, so he did. But within a week, the East Hampton, Conn., resident was filling up his car with the lowest octane fuel available.
"The extra cost seemed like a waste, and I've never had any problems with it," said Brown, an aeronautical engineer.
He is still driving the Maxima eight years later and has never needed a mechanic.
With gas prices high, consumers are fretting over the cost of filling up the tank. Those driving some of the most popular models, like the Honda Civic or the Chevy Impala, may not realize that they don't need to spend the extra 30 cents a gallon for high-octane gasoline.
"Some people think that their cars run better on a higher octane," said Sarah Miller, editor of World Gas Intelligence, which reports on trends in the natural gas market. “But if your car is built for regular and you put premium in it, you are wasting your money.”
With premium making up 15 percent of all gasoline pumped last year, it is clear that many Americans believe it adds to their car's mileage or lifespan.
The belief that high-octane gas is a better product likely stems from the years of advertising by oil companies, which claimed it “goes the extra mile” and “gets the knocks out.” Engine "knocks" occur when gas detonates too quickly, sending the piston up early and making the car lurch. This can lead to a decrease in performance and even engine damage.
But many experts say modern technology has eliminated the need for high-octane gas.
“Knock used to be a really big thing in the '70s and '80s,” said Philip Reed, author of "Strategies for Smart Car Buyers" and editor of Edmunds.com, an auto information Web site. “The computerization of cars has made engines much more sophisticated. Now they have sensors that can determine what you put in them and then make adjustments.”
In 1996, the Federal Trade Commission filed a false advertising complaint against Exxon that led to the end of television commercials promoting high-octane gas. As part of an agreement with the commission, Exxon produced new advertisements stating that regular gas was appropriate for most cars.
However, names like “V-Power,” “Super,” and “Power Plus” still seem to convey to many consumers that the high-octane versions are somehow superior.
That may be true, according to American Petroleum Institute, an industry association that represents a number of the larger gas companies, including Exxon Mobil, BP and Chevron. But if so, it has nothing to do with that magic octane number at the pump.
“Certain retailers, particularly major brands, will put in more than their share of required additives in their premium than in their regular gas,” said Patrick Kelly, a spokesman for API. “What you're taking advantage of is the extra additives, and not the higher octane.”
He said such additives were for “deposit control” and helped prevent carbon buildup in the engine that can cause the dreaded knocks.
“The knocking is a sign that there is something very wrong with the engine, and higher octane should eliminate that sound,” he said. “I usually blend the two, because my engine has high mileage, so I will typically top it off with some premium.”
Experts generally agree that some high-performance cars, including the Dodge Viper and Chevrolet Corvette, should use premium. Sports cars have different fuel chamber designs for faster speeds and acceleration, necessitating higher octane.
Standard SUVs, it turns out, don’t need the extra attention. These include models like the Chevy TrailBlazer, Jeep Grand Cherokee and Ford Explorer.
Reed of Edmunds.com advises drivers to study their owner's manuals to determine if a car should use premium gas. (They can also find the information on Edmunds.com.) Drivers should keep in mind that using low-octane gas in violation of a manufacturer's requirement might negate the warranty, Reed said.
Other experts say there is simply no better way to tell than to just test the gas.
“If a car engine knocks burning regular gas, then a premium is required,” said Dr. Roger Anderson, an energy expert at Columbia University. “If not, then you don't need the extra cost. The knocking is not destructive to the engine on an occasional basis, so I tell my students to try a tank of the cheaper gas and see.”
Hector Portorreal independently followed that advice with his 1999 Lincoln Town Car. The dealer who sold him the vehicle recommended regular gasoline. But at a Shell station in Manhattan recently, Portorreal eschewed regular at $2.61 in favor of the “V-Power” grade for 28 cents more a gallon.
“When I don't, it starts to run like this,” he said, violently shaking his fists up and down to simulate knocks.
As for the additives, Reed said any improvement in performance or gas mileage would be so slight it would probably not be worth the extra money.
But Anderson believes the additive detergents help keep his own engine clean.
“The soap, or detergent as it is officially called, was mainly to keep carburetors clean. But new fuel injection technologies don't need cleaning,” Anderson said.
Still, “I use premium in my Lexus for the soap.”