An internal combustion engine needs three things to get going: Air, fuel, and spark. The throttle body and intake plenum feed air, while injectors spray the right fuel mix into the combustion chamber.

Spark plugs are one of those maintenance items that, along with things like brake fluid and thermostats, are easily overlooked but extremely important to your car's safety, longevity, and performance.

A spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed aerosol gasoline by means of an electric spark. Spark plugs have an ...