Sep
4
High-Octane Nonsense
How much do you pay for gasoline? Do you pay extra for the high-octane, “premium” grade? If you get the premium stuff because it’s supposed to run hotter & cleaner, which is better for your engine, chances are, you’re getting taken for a ride.
People with an opinion on the subject can be quite passionate, especially those that say they’d never run their vehicles on anything less than “the best”. They insist that it gives them more power and keeps ’em running smooth. But, is premium grade fuel really worth the 20 cents or more extra per gallon than low-octane? What if my owner’s manual says I’ll get better performance with premium? Does it do what its fans say it does? Well, it really depends.
Many years ago, I remember bringing this up with my mechanic — one of those rare birds, an honest mechanic, with whom we had some friends in common. If I recall correctly, he indicated that higher-grade fuel does burn hotter, which in turn helps keep the engine running cleaner. He suggested testing it for myself to see if I got better performance. I wasn’t sure, but I ended up alternating Premium or Plus with the Regular for many years. (As gas prices went up, the frequency of the Plus fill-ups went down. Now, my car is on its last legs, anyway, so it gets a straight diet of Regular.)
When it comes down to it, most cars these days don’t really need the high-octane fuel, even if the owner’s manual recommends it. If you have an older car that knocks and pings, you should try a higher grade gas to see if you can eliminate that. (The knocking is caused by high pressure in the cylinders.) But, nowadays, engines come with advanced “knock sensors” that automatically adjust settings for various octanes. Thus, any anti-knock properties of premium gas may be superfluous.
The only other exception is “high performance” vehicles — i.e., luxury imports (e.g., Mercedes, Acura, Jaguar) and the occasional American sports/muscle cars (e.g., Corvette, Mustang). They are specifically designed with high-compression, high-revving engines, which need high-octane fuel to run smoothly. But, even they can run on Regular.
“Our cars must be able to drive all over the world, and so we are able to run on regular,” says Jakob Neusser, director of powertrain development at Porsche’s R&D center.
Yes, the low-octane will result in things like slightly reduced fuel efficiency and reduced power (probably no more than 5%). But, the average owner/driver will probably not even notice the difference.
As for the rest of us, putting a higher-octane mix in our engines when the manufacturer doesn’t even recommend it will not buy us better mileage, more power, or a cleaner engine.
One last thing… If you have a chance to get your gas at Wal-Mart or someplace like that rather than the big brand stations, go for it. As John Stossel sums it up in his book Myths, Lies, and Downright Stupidity:
“All gasoline, brand-name and no-name, comes from the same refineries. Brand names do use some different additives, but there’s no evidence that makes them superior. Save your money.”
