How many spark plugs are typically replaced per cylinder?

In a standard internal combustion engine, each cylinder typically contains one spark plug. The function of the spark plug is to ignite the air-fuel mixture, enabling combustion to occur within the engine's cylinders. Therefore, the number of spark plugs that need replacing directly corresponds to the number of cylinders in the engine.

When considering typical engine configurations, most passenger vehicles have between four to eight cylinders, meaning replacement would involve four to eight spark plugs. Therefore, the response suggesting 30 spark plugs does not fit within the standard range seen in typical engines.

The insight into the number of spark plugs is foundational in understanding engine maintenance and performance. Each spark plug works independently to produce the necessary spark for combustion, thus having one for each cylinder ensures that the engine operates efficiently.