The distance between the center and ground electrodes of a spark plug, known as the spark plug gap, is a critical parameter for optimal engine performance. This measurement, typically expressed in thousandths of an inch (inches) or millimeters (mm), directly influences the spark plug’s ability to ignite the air-fuel mixture within the engine’s combustion chamber. A correctly sized space ensures consistent and efficient combustion.
Maintaining the factory-specified setting offers several advantages. A properly sized gap promotes efficient fuel combustion, resulting in improved fuel economy and reduced emissions. It also ensures a smoother engine idle and better overall performance. Historically, specific settings were carefully determined by engineers to match the engine’s design and operating characteristics, considering factors like compression ratio and ignition system voltage.