Fuels splash octane

Octane ratings  

Understanding octane ratings.

About octane ratings

Octane rating is a measure of a fuel's ability to resist ‘knock’. The octane requirement of an engine varies with compression ratio, geometrical and mechanical considerations and operating conditions. The higher the octane number the greater the fuel’s resistance to knocking or pinging during combustion.

The octane ratings of Esso gasoline

  • Esso Regular Unleaded Octane 87
  • Esso Extra Unleaded Octane 89
  • Esso Supreme Unleaded Octane 91
  • Esso SUPREME+ Unleaded Octane 93

The right octane level for your vehicle

The recommended octane level for most vehicles is usually octane 87, but be sure to check your owner’s manual. Some car models have high-compression engines, which are designed to utilize octane levels of 89, 91 or higher. Ordinarily, your vehicle won’t benefit from using an octane higher than your owner's manual recommends. But if your engine knocks or pings at the recommended octane level, you may need a higher octane gasoline to prevent knocking.

FAQs about octane ratings

A small percentage of vehicles may require higher octane gasoline under certain operating conditions because of variations in engines of the same model due to manufacturing tolerances, or because of an unusual build-up of engine deposits. A small percentage of vehicles may knock because of variations in engines of the same model due to manufacturing tolerances, or because of an unusual build-up of engine deposits. Other factors such as extremely hot weather, changes in altitude or hard driving conditions (like towing a heavy load) may also cause knocking. Many modern vehicles are equipped with an electronic device that detects and eliminates light knocking before you hear it.
In general, the octane a vehicle needs aligns with the manufacturer’s recommendation. However, each vehicle is different, owing to factors such as manufacturing variability, mileage, type of operation and general condition. As a result, some vehicles may require a higher octane, particularly after an initial period of operation. If knocking or pinging begins to occur, using a higher octane grade may resolve the problem.
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Esso and Esso Extra are trademarks of Imperial Oil Limited. Imperial Oil, licensee.
**Improvements, such as fuel economy, are based based on Synergy-branded gasoline, where available, compared to gasoline meeting minimum Canadian government detergency standards. Actual benefits will vary depending on factors such as vehicle type, driving style, and gasoline previously used. All trademarks used herein are trademarks or registered trademarks of Exxon Mobil Corporation or one of its subsidiaries.