With all the choices at the pump now, what exactly is the difference between “regular” and “premium” unleaded gasoline? Both are made from the same raw material; however, regular and premium gas differ in a few ways. Knowing the differences helps you make an educated choice when buying fuel, and may save you a bit of money at the pump or service station.
There are three major distinctions between regular-grade gasoline and premium-grade gasoline.
Price
The first (and most apparent) difference is readily viewable on any gas station sign: the price. Typically, the price of premium gasoline ranges from 20-30 cents more per gallon. Depending on how often you fill up at the pump, that can be an increase in fuel costs up to $200 a year.
Octane Rating
The second (and less understood) difference is the octane rating. Regular gasoline usually has an octane rating of 87. Premium gasoline tends to have an octane rating somewhere between 91-93. Mid-range gasolines fall in the middle of the spectrum.
Octane rating measures the fuels ability to resist specific engine noise as gasoline ignites. The higher the rating, the greater the fuel’s resistance to knocking or pinging during combustion.
When fuel in the combustion chamber prematurely ignites, engine knock occurs -- disrupting the engine’s operation.
Additives
The third (and often shooed) difference is gasoline additives. While all gasolines produced by major manufacturers today contain some form of cleansing additives, premium gasolines are advertised as having extra, or more powerful detergents to help clean engine components. Carbon build-up and other engine crud can hurt performance over time -- hence, additives in gas.
The Choice is Yours
Debates over which fuel is best for your vehicle run rampant on the internet. We’re not going to lay down any law here; however, here are a few keys to consider.
You may have a vehicle with a high-compression engine. These engines typically run best using a higher-octane. Check your owner’s manual for recommendations.
Consistent engine knock may be a sign that fuel is igniting too early in the combustion process. Using gasoline with a higher octane rating may help eliminate the knock.
Over a course of a car’s life, even under typical loads, engines will eventually collect some grime. Switching to a premium-grade gas with more additives may help flush the system faster than regular gasoline.
What’s your preference at the pump? Let us know in the comment section below.