Spark plugs are necessary for gas-powered engines. However, they're not all the same, and they can come in different shapes and sizes. Here's why that is.

Not all spark plugs are created equal, and knowing which one your car needs can vastly improve your car's fuel economy.

Spark plugs help you start gasoline engines and glow plugs do the same in diesel engines. But how do they go about providing ...

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 ...