Where to Check the Model Number of a Spark Plug?

[StJason]

Spark plug model numbers can be viewed on the casing. Spark plugs are installed on the side or top of the engine. In earlier models, spark plugs were connected to the distributor via ignition cables, but over the past decade, most car engines have transitioned to direct connection between ignition coils and spark plugs. Main types of spark plugs include: Standard spark plugs, extended insulator spark plugs, electrode spark plugs, seat-type spark plugs, pin-type spark plugs, and surface-gap spark plugs. How spark plugs work: The ground electrode of a spark plug connects to the metal casing, which is threaded into the engine block via the cylinder head. The insulator primarily isolates the metal casing from the center electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and center electrode, it ionizes the medium between the center electrode and ground electrode to generate a spark, thereby igniting the air-fuel mixture in the cylinder.