Gas-powered internal combustion engines need spark plugs to (literally) ignite and complete the combustion stroke, enabling the motor to produce power. They may seem unusual to the untrained eye, but ...

The spark plugs in a gasoline engine are not universal, one-size-fits-all components. Plugs are made of a variety of materials with different electrode setups and thread configurations, and knowing ...

For hot rodders, spark plugs are often nothing more than inspection tools that reveal whether an engine is running too rich, too lean, or just right. Street guys look for a nice tannish-brown tint on ...