Many of our customers think that using premium fuel will mean a longer-lasting engine, and they repeat unfortunate myths about premium fuel having better detergents than regular fuel. It’s just marketing. If you’re unsure about what to use to fuel your engine, first check your owner’s manual. If premium is ever going to be helpful, it will be listed. Don’t waste your cash.

When automobile engines aren’t designed for premium gas, they never need the higher-octane fuel. It is all about combustion. Premium gasoline ignites at a higher temperature, so it can handle high levels of compression without reigniting. It also has lower levels of heptanes, which also prevents re-ignition. Even the government regulators agree – there’s no reason for it in the average tank.

If your owner’s manual does call for premium gasoline, chances are you don’t always want it. Especially if you drive a 1996 or later because those engines are likely to have technology that adjusts to different octanes. With higher-performance engines that are intended to use premium gasoline, the low-temperature can mean better performance. The premium fuel also prevents knocking or pinging sounds. But the difference is usually unnoticeable, and the price difference is dramatic. The only exception is for cars that have knocking noises when regular fuel is being used, even under everyday driving conditions. For these vehicles, do a little more research or talk to one of our ACE-certified auto experts about using the right gasoline.

Is There a Diesel vs. Gasoline Difference?

Premium and regular can mix, but not with diesel. If you drive a diesel, filling the tank with gasoline will cause it to fail completely. Then, you’ll have to pay the high costs of flushing the system of gas. Diesel is thick and oily compared to gas, and gasoline engines are different in many ways. These don’t have spark plugs. Instead, the fuel is injected directly and ignited by heat. With gasoline, air and fuel are mixed first and then the spark plugs do their work.

Contact Christian Brothers

If you have questions about how to fill your gas tank or if you’re having any problems with your fuel system, give our trusted mechanics in Fort Mill, SC a ring. We can help with everything from looking at cars you’re considering purchasing to maintenance-related spark plug tune-ups or even diagnosis and repair of bigger problems.