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 ...

Side gapping your car's spark plugs could result in some modest performance gains. Here's what it means, how to do it, and why it works.

Spark plugs are small, cylindrical devices that use electricity to trigger combustion of the gas/air mixture in engines, allowing them to start and continue running. They do this by turning incoming ...