Do I need to use premium gas in my car?

As an auto dealer, this is a question we get a lot, and this blog post is intended to help clear up some of the myths and misconceptions about whether you need premium gas or not. By using the right kind of gas in your car, you could potentially save hundreds of dollars a year!

Generally speaking, the only difference between different grades of fuel is the octane rating, despite what oil companies' marketing would like you to believe. In order to ensure compatibilitiy with carmakers' requirements, even regular gas contains more than the mimimum levels of additives and detergents required by all automakers. Octane ratings are defined by the ability of gasoline to resist preignition of the fuel/air mixture in the engine's cylinders. Some sports cars or cars with high-performance engines operate under a high compression ratio. If such engines require premium fuel and you put in regular fuel, the preignition can cause a pinging noise, called knock. Knocking can damage engines and is to be avoided at all costs. The best way to find out what kind of fuel you should use in your car is by consulting your owner's manual or filler flap. Here, you'll find what grade of gas you should be using. You're likely to find three phrases that indicate what kind of fuel to use:

1. Premium fuel REQUIRED - Your car's engine was designed to use premium gas, and if you don't, the engine could knock and cause damage.

2. Premium fuel RECOMMENDED - For maximum performance and MPGs, you should use premium gas. Today's cars have sophisticated electronics onboard, and combined with a device called a knock sensor, they have the ability to detect knock and make automatic adjustments to prevent damage. You can use regular fuel, but there might be a small hit in performance or economy.

3. No recommendation or requirement for premium fuel - Your car wasn't designed for it, so it doesn't need it.

Save your money - you won't gain anything from using premium fuel. Hopefully this clears the air a bit, and if you've been using premium fuel but didn't need it all along, you stand to be a few hundred dollars richer every year!