Should you use an octane rated higher than your vehicle needs? No. It’s mostly a waste of money. The suggested octane rating for most vehicles is 87, or regular fuel. Some people believe using a higher octane gas may help performance and gas mileage, but you are likely to see 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.
Octane Rating and Performance
The numbers on the pump at the gas station — generally, 87, 89, 91, and 93 — refer to the octane rating. Octane is a measurement of the amount of compression your vehicle’s fuel can withstand before it combusts. One way to look at it is the higher the octane number, the better the fuel burns in the engine. This, however, does not mean every car needs high-octane fuel to function properly.
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 performance. 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, 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. That being said, 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, it’s up to you to decide what you want to put in your car.
Using an Octane Rated Lower Than Your Vehicle Needs
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 — or 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.
Most modern cars will adjust their tune to accept lower-grade fuel, though your performance will suffer somewhat.
Using an octane rated higher than your vehicle: savvy or senseless? 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.
You can use an octane rating higher than your car needs, but it is not necessary, and there are little to no benefits when driving under normal conditions. It’s not advised, however, to use a lower octane rating than is suggested by your car’s owner’s manual. For more on gas quality, see our articles: Kroger Gas Quality: Is Kroger Gas TOP TIER? Who Supplies Kroger Gas? and Is 76 Gas Good? and Costco and Sam’s Club Fuel Quality: Pump or Pass