Open Road

High-octane gas key to improved performance?

Open Road

(Photo: Wisconsin Department of Natural Resources | Flickr)

Serious drivers look to a gasoline's octane rating for a higher performance guarantee. Unfortunately, there are misconceptions and old wives' tales that leave you paying more than you have to for already pricey gasoline. Then again, there is a time when the premium is the only choice.

Why care about the octane rating in the first place?

When fueling up your vehicle, the fuel-air mixture undergoes significant compression prior to detonating, and many performance engines derive more energy from the premium fuel. Using an improperly low octane rating can lead to abnormal combustion patterns and the infamous engine knock.

Why buy high-octane gas when the regular stuff is cheaper?

Your car's engine is designed for a high-octane fuel. Your owner's manual will tell you if your car should be powered with high-octane gasoline. Ignoring this requirement can set off abnormal combustion and greatly decreases your engine's ability to draw energy effectively from the gasoline.

Your engine pings. Even if you still have the original engine in your car, and even if the owner's manual suggests a lower-octane rating, you can make the case for using high-octane gasoline instead. Exxon notes that "manufacturing variability, mileage, type of operation and general condition" can result in the need for the more expensive fuel even if the owner's manual begs to differ.

It is interesting to note that the pings may only occur under certain conditions. For example, if you take a trip through Death Valley in the middle of July, or if you’re towing a horse trailer, the increased load can cause result in a loss in engine performance due to knocking, or the ECU retarding ignition timing. Giving it a treat of high-octane gasoline may increase power.

Of course, it pays to know the old wives' tales that are out there as well. High-octane gasoline will not clean your engine any better than the low-octane fuel, and engines designed for lower octane fuel won’t see a bump in performance in using jet-grade fuel. The Federal Trade Commission notes that this is a frequent performance rumor that simply does not hold any truth.

Content by Sylvia Cochran.

View Comments