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 ...

Read a good spark plug lately? We hope so, for your engine's sake. But spark plug reading—the traditional way to check your fuel mixture and monitor other vital conditions in the combustion chamber ...

The spark plugs inside your car's gas engine are remarkably durable and could last for dozens of oil changes before needing to be replaced. For components that withstand intense heat, pressure, ...