Are You Wasting Your Money on Premium Gasoline?

You may have heard that premium gasoline is better for your car, but in most cases that statement is wrong! Many people buy premium over regular, but this expensive fuel is only needed in very few vehicles. But doesn't it make the car run better? What about the engine being cleaner? And of course there is the fact that you get better gas mileage right? Sorry, but the answer to these questions is no. Premium is a waste of the average consumer's money.

So what is the difference between premium gasoline and regular? It is all about preventing engine knock. Regular fuel has a lower anti-knock index (AKI) while premium gas has a higher AKI. The higher the AKI, the more knock protection offered. Knocking happens when fuel ignites before the spark plug ignites. If this happens you will hear a knocking sound, something that sounds like marbles rattling around in a can. Knocking can damage an engine and this is why higher AKI fuels are available to combat this problem. The knocking will cease with premium gas since it burns more slowly than regular, requiring more heat before it can ignite.

So what else does premium gas offer? Absolutely nothing. Basically all you get out of spending that extra cash is anti-knock protection. And guess what? Most cars don't need that extra protection. You only need a higher AKI fuel if your engine knocks without it or if you have an engine with a supercharger. Premium gas won't give you better performance, make you go faster, or get you better mileage. And it also won't lead to a cleaner engine, since any "cleaners" present in the premium gas aren't available in sufficient quantities to do any real good.

In fact, there are some instances when premium works against your car. Because of the fact that premium is harder to ignite, some engines won't start as quickly or run as smoothly as they do with regular gas. Higher AKI fuels can also pose a problem in cold weather for the same reason. In addition to the start up problem, premium gas is slightly denser than regular gas which can lead to buildup of waste in the engine.