Detonation in a car's engine, otherwise known as spark knock, occurs when fuel fails to burn smoothly and consistently, instead combusting unpredictably. It occurs when there is too much heat and pressure in the combustion chamber, the part of the engine where the fuel is burned.
Detonation typically occurs when a car is accelerating or being driven in too low of a gear for the engine speed and load conditions. This could be when passing on the highway, towing a trailer or climbing a steep hill.
The most obvious symptom of detonation is a knocking or pinging noise coming from the engine. If allowed to continue for any length of time, detonation may cause damage to the engine pistons or failure of the head gasket.
One of the easiest ways to prevent detonation is to use high-octane fuel. Mechanically, fitting a cold-air intake is a relatively easy and inexpensive way of preventing detonation, too.
