Posted on 28November2025
Spark plugs and glow plugs serve different jobs. Spark plugs ignite a precise air-fuel mixture in gasoline engines using an electrical spark. Glow plugs preheat the combustion chamber in diesel engines so injected fuel ignites from compression, especially when the engine is cold. Both are small, threaded devices in the cylinder head, but their purpose, operation, and service needs are not the same. What Each Component Actually Does A spark plug makes a controlled spark across ... read more