A Tale of Three Petrols: Regular, Premium and Diesel

Driving is already expensive, but the kind of gas you use can make it even worse. Fortunately, you will almost never get benefit from anything more costly than regular low-octane fuel.

There are not any engine cleaning benefits, and costly gasoline usually doesn’t mean a longer-lasting engine. It’s mostly just a marketing ploy. Read the owner’s manual. If premium fuel isn’t listed specifically, you will never need it. If the requirement isn’t there, avoid premium and save cash.

When automobile engines aren’t designed for premium fuel, they never benefit from the higher-octane fuel. It has to do with how the fuel is ignited. Premium gas ignites at a higher temperature, so it can handle high levels of compression without reigniting. Pricier fuel also has a lower concentration of heptanes, which also prevents reignition. Even the government regulators agree – there’s no advantage for it in the average tank.

If your owner’s manual does call for premium fuel, 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 timing properly. With premium-designed engines that are intended to use premium fuel, the lower ignition rate can mean better performance. The expensive unleaded gasoline also prevents pinging or knocking noises. However, if you’re not going fo top performance, the difference in performance is minimal but the cost is far greater. The only exception is for cars that have knocking noises when regular fuel is in the tank, even under normal driving conditions. For these vehicles, do a little more research or ask our ACE-certified mechanics about using the right fuel.

Is There a Diesel vs. Gasoline Difference?

Premium and regular can mix, but not with diesel. You could stall the engine and make it unusable. You’ll need a complete flush. Diesel is a little grimier and much thicker than unleaded, and the engines are different in a few ways. These don’t include spark plugs. Instead, the fuel is ignited by the heat of compressed air, which is compressed before the fuel is injected directly into the combustion chamber. With gas engines, fuel and air are mixed first and then the spark plugs cause ignition.

Contact Christian Brothers Today

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 technicians in Allen, TX a call. We can help with everything from inspecting automobiles you’re considering purchasing to tune-ups and repairs.