Spark plugs are a mission-critical part of a gasoline engine's ignition system. Without them, there's nothing to ignite the air-fuel mixture in each cylinder.

Although the definition of spark-plug gap is intuitive for those who know what plugs are, we feel an explanation is good and necessary information for rookies, and a solid refresher for the OGs.

Piston-engine aircraft use more than one spark plug per cylinder, and for good reason. Beyond performance gains, it all comes ...

Spark plugs are often overlooked, but for good reason. Decades of testing have proven: if the ignition system is sufficient and working properly, gains from the latest whiz-bang spark plugs, fat ...

Japanese scientists are creating laser igniters that could one day replace spark plugs, resulting in better-performing, more efficient and cleaner-running engines.