The glow number characterizes the heat load of the candle. The lower the glow number of the candle, the higher its thermal load. The candle can also conduct heat better, which prevents harmful pre-ignition (engine knock). A candle with a high heat load also has the disadvantage that its self-cleaning temperature is higher. It is therefore more prone to the formation of soot, especially when the engine rarely reaches its operating temperature in motion (urban traffic mode, short trips in winter). Usually, «cold» spark plugs are installed on «hot» engines, as well as power units that require more power. The glow number of a candle is usually contained in its designation.
Note: The replacement of spark plugs is described in chapter «Maintenance operations».
Required spark plugs
Attention: Technological progress is ongoing. Therefore, it may be that other models of spark plugs can be used. In this regard, when buying new spark plugs, it is recommended to consult a workshop or a store.