The premature combustion of the fuel–air mixture in an internal combustion engine.
- ‘To run an engine on unleaded fuel it may be necessary to retard the initial timing to prevent detonation and/or pre-ignition.’
- ‘Early ignition or runaway pre-ignition causes higher combustion chamber temperatures that can wreck the engine.’
- ‘High-octane fuel simply allows the higher pressures and temperatures in these high-output engines by preventing pre-ignition.’
We take a look at several popular, though confusing, punctuation marks.