At what mileage should spark plugs generally be replaced in a car?
2 Answers
Under normal maintenance conditions, spark plugs should be replaced after driving 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine type, so it is recommended to follow the user manual. The following standards can be referenced for maintenance and replacement: platinum spark plugs should be replaced at 40,000 kilometers, ordinary nickel alloy spark plugs at 20,000 kilometers, and iridium spark plugs at 60,000 to 80,000 kilometers. Damaged spark plugs may exhibit the following symptoms: difficulty starting the engine, reduced power, excessive exhaust emissions, and increased fuel consumption. Steps for replacing spark plugs: Open the hood and lift the plastic cover of the engine. Remove the high-voltage ignition wires, marking each cylinder's position to avoid confusion. Use a spark plug socket to remove the spark plugs one by one. While removing them, check for any external debris such as leaves or dust and ensure they are thoroughly cleaned. Place the new spark plugs into the spark plug holes, hand-tighten them a few turns, and then use the socket to tighten them further. Reinstall the high-voltage ignition wires in the correct firing order and secure the cover.
When I used to drive, spark plugs generally needed to be replaced every 30,000 to 50,000 kilometers, depending on the car brand and daily usage. For example, Japanese cars like Toyota and Honda recommend around 40,000 kilometers in their manuals, while German cars like BMW and Mercedes may extend to 60,000 kilometers. If the spark plugs age, the engine tends to shake, fuel consumption increases significantly, and ignition becomes less smooth. I mostly drive in urban areas with frequent traffic jams and stop-and-go conditions, which causes faster wear, so I get them checked and replaced at 40,000 kilometers. I recommend not skimping on cost—using good platinum or iridium spark plugs can extend their lifespan and maintain smooth driving. Forgetting to replace them could lead to stalling on the road, so it’s better to replace them early for peace of mind.
