Spark plug, commonly known as flame nozzle, is used to discharge the pulse high-voltage electricity sent by the high-voltage wire (flame nozzle wire), breakdown the air between the two electrodes of the spark plug, and generate an electric spark to ignite the mixed gas in the cylinder. The main types include: standard type spark plugs, edge protruding spark plugs, electrode type spark plugs, seat type spark plugs, pole type spark plugs, surface jumping spark plugs, etc.

The replacement cycle of spark plugs is directly related to their material. The replacement cycle of nickel alloy spark plugs is 20000 to 30000 kilometers, nickel yttrium alloy spark plugs are 30000 kilometers, single platinum spark plugs are 40000 kilometers, double platinum spark plugs are 60000 kilometers, iridium spark plugs are 80000 kilometers, and platinum iridium alloy spark plugs can reach 100000 kilometers.