Octane ratings
Understanding octane ratings
Octane ratings are the measure of a fuel’s ability to resist autoignition (commonly referred to as “knock”). Octane requirements of engines vary with compression ratios, geometrical and mechanical considerations and operating conditions. The greater the fuel’s ability to resist knocking or pinging during combustion, the higher the octane rating.
Mobil™ gasoline octane ratings
- Mobil Regular gasoline – Octane 87
- Mobil Extra gasoline – Octane 89
- Mobil Supreme+™ gasoline – Octane 91–93
What octane level is right for your vehicle?
To determine the recommended octane level for your vehicle, refer to your vehicle’s owner’s manual.
Want to learn more about octane ratings?
View our FAQs-
Get more out of every trip
Explore our comprehensive list of tips to help you improve fuel efficiency and get more out of every trip.
Get fuel tips -
Quality fuels to get you where you're going
Discover what steps we take to ensure the quality of our fuels.
About our quality -
Stay safe around fuel
Simple steps to protect you and your family when fueling up or storing gas.
View safety tips -
Understanding ethanol types
Learn about ethanol in fuel and how to choose the right fuel type for your vehicle.
Explore ethanol types
Engine keep-clean benefits based on Exxon Supreme+™ and Mobil Supreme+™ premium gas compared to regular gas in port fuel injected engines. Deposit removal, fuel economy and wear benefits based on comparison of Exxon Supreme+ and Mobil Supreme+ premium gas to gasoline that meets minimum government standards. Wear reduction was measured based on an industry standard lubricant test. Actual benefits are based on continuous use and may vary depending on vehicle type, driving style, and gasoline previously used. Concentration and availability of our proprietary additive package may vary.