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 ...

When building a custom engine combination, it becomes a challenge to choose the right spark plugs, since there are often no factory reference points from which to start. And this is much more than ...

Your engine’s spark plugs are one of its smallest and most important, parts. We look at some of the best. The engine in your car, truck, or crossover operates on the simple principle of capturing the ...