Posts Tagged: pre-ignition

Pre-ignition and detonation (knock) — What’s the difference?

There’s a difference between pre-ignition versus detonation (knock) Many car “experts” use the terms pre-ignition and detonation interchangeably or blame pre-ignition on low octane fuel. Let’s set the record straight; pre-ignition and detonation are not the same, they occur in different phases of the four-stroke process and only one is caused by using low octane fuel. What is pre-ignition? Pre-ignition is defined as starting the combustion process BEFORE the spark plug fires. It occurs during the compression stroke. Pre-ignition is caused when a hot object/area in the combustion chamber ignites … Read More