How to Identify Spark Plug Models?

[VonBrayden]

Method for identifying spark plug models: For example, 5SKHR550: 5S represents the 5th generation dual iridium core 5S premium version; KHR indicates the shape with a washer flat seat; H denotes the thread length of 26.5mm; R signifies the shape with an attached resistor; 5 is the gap code, representing 0.20 plus 0.50mm; 50 is the gap increment of 0.50mm. The gap between the spark plug electrodes significantly impacts its performance. If the gap is too small, the spark will be weak and prone to carbon buildup causing leakage. If the gap is too large, the required breakdown voltage increases, making the engine harder to start and more likely to misfire at high speeds.