How many kilometers do spark plugs need to be replaced?

[VonEverett]

Replacement cycle of spark plugs: Under normal maintenance conditions, they should be replaced after driving 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine, so it is recommended to follow the user manual. The following standards can be used as a reference 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. Methods to determine if spark plugs are damaged: Remove the spark plugs and observe them. The condition of the spark plugs can be judged based on their appearance and color. Normal spark plugs have an insulator skirt and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has a reddish-brown insulator skirt, an electrode gap between 0.8-0.9mm, and no signs of electrode burn. If the spark plug is contaminated with oil or deposits but is not damaged, it can continue to be used after cleaning off the oil and deposits. If the spark plug is severely damaged, with signs such as blistering at the top, black streaks, cracks, or melted electrodes, the cause of the damage should be identified. After troubleshooting, replace the spark plug with a new one. Additionally, if the spark plug appears black as if smoked, it indicates that the wrong heat range was selected or that the air-fuel mixture is too rich, with oil seeping up.

[DelAlivia]

When it comes to spark plug replacement, I'd like to share my personal experience. As an average car owner with over a decade of driving experience, spark plug lifespan varies by type. Standard copper spark plugs typically need replacement every 30,000 to 50,000 kilometers, otherwise ignition becomes less efficient. Platinum plugs can last 60,000 to 100,000 km, while iridium plugs are even more durable, often exceeding 120,000 km. Driving habits matter too - frequent city traffic jams lead to incomplete fuel combustion, causing faster carbon buildup on spark plugs, so early inspection is necessary. Symptom-wise, if you experience hard starting or sudden fuel consumption spikes, it might indicate worn spark plugs. Delaying replacement not only damages the engine but also increases repair costs, which is why I always check the manual and visit a professional shop every 50,000 km.

[VanIan]

The replacement mileage for spark plugs varies significantly. According to my research, copper spark plugs are recommended to be replaced at around 35,000 kilometers, platinum ones last longer, approximately 80,000 kilometers, while iridium spark plugs are the most durable, and it's fine to replace them only after 120,000 to 150,000 kilometers. This is related to driving conditions. I drive an SUV in rural areas, and the wear is faster when the road conditions are poor, so I switched to high-performance iridium spark plugs for convenience. Checking them is simple—just listen to whether the engine starts smoothly and feel if there's any hesitation during acceleration, and you'll get a good idea. Long-term neglect may lead to excessive exhaust emissions or reduced power. For safety, I perform regular maintenance to prevent small issues from becoming big problems.

[MacIsaac]

Spark plugs are crucial components of the ignition system, and their replacement intervals depend on the material. Copper spark plugs typically have a shorter lifespan of 30,000-40,000 km and require earlier replacement. Platinum plugs are more stable, lasting approximately 50,000-80,000 km. Iridium plugs are higher-end and can still function beyond 100,000 km. Based on my multiple experiences, aggressive driving styles consume spark plugs faster. In terms of performance, if you experience delayed starts or engine vibrations, it's highly likely time for a replacement, otherwise fuel efficiency will be affected. I adhere to inspecting them every 40,000 km - prevention is always the wisest approach.