Using an Octane Rated Higher Than Your Vehicle Needs: Pros & Cons

The suggested octane rating for most vehicles is 87 (or “regular fuel), and using an octane rated higher than your vehicle needs is generally a waste of money. Some people believe using a higher octane gas may help performance and gas mileage, but there is likely to be little to no benefit. However, if your car requires high-octane fuel — such as mid-grade or premium — it is not a good idea to use an octane rated lower than what’s recommended for your vehicle. This can result in engine damage and can even void your warranty. For more about using a fuel octane higher or lower than your vehicle’s needs, see below.

Octane Rating and Performance

The numbers on the pump at the gas station — typically 87, 89, 91, and 93 — refer to the fuel’s octane rating. Octane is a measurement of the amount of compression your vehicle’s fuel can withstand before it combusts. Essentially, the higher the octane number, the better the fuel burns in the engine. This, however, does not mean that every car needs high-octane fuel to function properly. Additionally, higher octane fuel does not have more detergents or helpful additives that clean your engine — the Environmental Protection Agency (EPA) sets detergent standards across all octanes.

The suggested octane rating for most vehicles is 87, or regular fuel. You can check your car’s owner’s manual to confirm the manufacturer’s fuel recommendations. Also, keep in mind that octane requirements can change based on operating and environmental conditions; consult a mechanic or car dealership for guidance.

High-performance cars like sports cars require fuel that is mid-grade or premium. Mid-grade gasoline is rated 88 to 90, and premium gasoline is rated 91 to 94, according to the Department of Energy. There are higher pressures in performance vehicles, requiring higher octane fuel to avoid damage to the engine.

Using an Octane Rated Higher Than Your Vehicle Needs

High-octane fuel is not necessary for all vehicles, but some people believe that using a higher octane than required improves fuel economy and/or decreases carbon emissions. However, under normal driving conditions, you are likely to see little to no benefit. If you are towing a trailer or driving in particularly hot weather, high-octane gas may marginally help gas mileage and performance.

Before you decide what to use at the pump, you’ll want to consider the price of high-octane fuel. It’s considerably more expensive than standard gasoline because the fuel components that are present in high-octane fuel are more expensive to produce. If your vehicle requires mid-grade or premium fuel, it’s worth it to spend the extra money at the pump to avoid costly repairs to your engine. But, if your vehicle doesn’t require premium fuel, buying higher octane fuel is generally a waste of money, according to the U.S. Federal Trade Commission (FTC).

Using an Octane Rated Lower Than Your Vehicle Needs

While using a fuel octane higher than your car needs is not harmful to your car, it is not advised to use a lower octane rating than your car needs. This can lead to engine “knocking,” which occurs when the fuel burns unevenly in the engine. Persistent knocking can lead to long-term engine damage. Lower octane fuel in a vehicle that requires premium can also cause the engine to operate poorly, which can lead to malfunctioning of the engine and emissions control system. Additionally, using a lower octane fuel than recommended can void your warranty.

TOP TIER Gasoline

If you’re looking for gasoline that will benefit your car, consider buying your fuel from a retailer that sells TOP TIER gasoline. TOP TIER gas was developed by a group of auto manufacturers, and it contains more than three times the amount of detergent additives mandated by the EPA, and the additives are found in all octane levels. This type of gasoline is known to be helpful for improving engine performance and preventing deposit buildup.

For more about retailers that sell TOP TIER gas, see our articles about the gas quality at 76, ARCO, Mobil, Sunoco, and Valero.

In Summary

It’s best to use the octane rating suggested for your car by the manufacturer — most vehicles only require standard fuel. You can check your car’s owner’s manual to confirm the manufacturer’s fuel recommendations. There are little to no benefits to using an octane higher than your car needs, but if you use a lower octane than your car needs, you risk damaging the engine. If you’re looking for the highest quality fuel, consider getting your gas from a TOP TIER licensed retailer.