Mercedes-Benz Brand Assets

Mercedes-Benz Brand Assets

505 W. Franklin St., Chapel Hill, NC 27516

Ask a Technician: Should I Opt for Premium Gas?

by Client

Q. My owner’s manual says that regular unleaded is fine for my vehicle. Would it be better for my car if I splurged on premium gas or is that an unnecessary waste of money?

A. Save your money. If your Client owner’s manual recommends regular unleaded, then regular unleaded is perfectly fine. You’re just wasting precious pennies if you pay for a higher octane fuel. Most of today’s cars, with the exception of high-performance engines, are tuned to run on regular unleaded fuel. And there’s no advantage to be gained by using premium.

Here’s the Skinny:

Your engine’s cylinders hold a mixture of gas and air. The cylinder compresses that mixture very quickly and your spark plug ignites it. That little explosion (like a cannon firing) is the combustion in an “internal combustion engine” and creates the energy to make your car go. The octane of a gasoline tells you how much compression it can stand before it ignites spontaneously. The higher the octane, the higher the compression it can take.

Most cars have an eight-to-one compression ratio, which is perfect for regular unleaded gas. That means the cylinder is compressing the gas/air mixture at just the right rate.

If the gas isn’t a high enough grade for the compression rate of the cylinder, it’ll ignite early, before the spark from the spark plug. And that’s bad for your engine. Those early explosions result in knocking and pinging. So, if you don’t hear any knocking and pinging, you’re using the right grade of gas. If you do hear those sounds, try upgrading to a premium gas. But, for most cars, using a premium gas doesn’t give you or your engine any advantage.

Now you know! If you have any more questions, feel free to contact us or head over to our dealership at 505 W. Franklin St., Chapel Hill, NC 27516.