While driving home you hear a beeping sound form your car that brings to your attention the yellow light on your dash, signifying your low on gas. The closest gas station you can find is one of those discount brand stations. You’re not sure if the significantly cheaper gas is good for your cars engine? You’re not sure if the low octane gas is good for your engine or if the premium is better? No matter the make or model of your vehicle you should be aware of the proper quality and octane level of gas is right for the optimal performance of the engine. Not all cars require high octane gas so knowing your vehicles needs is the best for the longevity of its engine.
The Difference Between Unleaded & Premium Gas
Before we discuss the difference between gasoline brands. It’s best to know the difference between unleaded regular and high octane premium gas. When discussing the difference its best to have some knowledge of how combustion in a cars engine works. Every gasoline powered engine uses the process of internal combustion.
During this process gasoline is injected into the engine compartment where it is ignited by the spark plugs. when this happens the remaining fuel and air mixture explodes above the engines cylinder driving it downward. all the cylinders in the engine fire in a timed cycle called the firing order. The firing off the cylinders in time force the pistons to move, which turns the crankshaft.
What Is Preignition, Aka Engine Knock
If the air fuel mixture fires off too soon or leak out before the spark plug ignites the injected fuel, it causes what is known as an engine knock.
Knocking is a clicking or pinging sound you may hear from the engine while driving. Engine knock is very bad for your cars engine. Why would an engine allow the air and fuel mixture to be fire off too soon?
What is the right Octane Level for my car?
Crude oil is a mixture of different chemicals called hydrocarbons. Gasoline is just one of the refined elements distilled from crude oil. Gasoline is made up of individual molecules that have both carbon and hydrogen atoms. Different kinds of fuels have different combinations of hydrocarbons.
The more octane added to gasoline, the higher the resistance it has to spontaneous exploding (preignition). So the higher the octane fuel has less chance to make your cars engine knock. Premium gas is usually going to have an octane level around 91. While regular gasoline is around 85 to 87 octane. Higher octane fuel burns at a slower rate than lower octane fuel.
Premium does not necessarily indicate a fuel is “better” for your car as much as whether it is “right” for your car. Cars designed for standard unleaded fuel could perform worse with high octane gasoline with a burn rate that is slower. High performance vehicles require the slower burn rate of high octane fuel to defend against engine knock, which is not optimal for performance and longevity of its engine.
Is Premium Gas Better?
Premium levels of octane are designed for aggressive, high performance engines. Non-performance engines don’t need premium fuel.
Check you vehicles owners manual to determine if your car or truck needs premium fuel or is fine with just regular octane gas. If you have a vehicle such as a BMW, Mercedes, Porsche or just about any vehicle designed specifically for high performance, then premium fuel Premium fuel is best. If your engine isn’t designed for high octane, then it will do nothing for your vehicle but cost you more per fill-up.
Cheap Station Gas Or. Name Brand Gas
Now that you have a better understanding of gasoline octane levels, we can get back to the question whether or not cheap brand or name brand is better for your vehicle. Both types of gas stations are going to have similar octane level fuel. The low octane gasoline may have an 85 octane level instead of an 87. An occasional fill-up with this fuel isn’t going to harm your engine. Name brand gas stations have a specialized formulas they create that have different chemical elements designed to clean your engine. For the most part there is no noticeable difference in performance. Go with what’s cheap unless you feel that you want to fill up with higher end detergent gasoline that can increase the longevity your newer vehicles engine.
For a greater understanding of gas quality, checkout this article on edmunds.com