Octane rating (RON)

The octane rating shows how well petrol resists self-igniting under compression, which causes knocking (detonation). It does not measure energy content: higher-octane fuel does not contain more power by itself.

European pumps show RON (Research Octane Number), typically 95 and 98. In the USA pumps show an average of RON and MON, so “91” there is roughly equal to 95 RON here. Always follow the minimum octane in your owner's manual.

High-compression sports engines may need 98 to perform as designed; most commuter, scooter and off-road engines run fine on 95. Using higher octane than required brings no gain. Note E10 compatibility for older bikes and carburettor engines, and use E5 or stabilised fuel for long storage.