How Often Should Original Spark Plugs Be Replaced?
3 Answers
How often original spark plugs should be replaced depends on the material of the spark plugs. The replacement interval for ordinary nickel alloy spark plugs is approximately 20,000 kilometers; for platinum spark plugs, it is 35,000 to 45,000 kilometers; and for iridium spark plugs, it is 65,000 to 75,000 kilometers. Common spark plug faults can be summarized into two types: 1. Severe spark plug erosion; 2. Spark plug deposits. Spark plugs, commonly known as "fire mouths," function by discharging the high-voltage pulses sent through the high-voltage wires (spark plug wires), breaking down the air between the two electrodes to generate an electric spark, thereby igniting the air-fuel mixture in the cylinder. The main types of spark plugs include: standard spark plugs, insulator projection spark plugs, electrode-type spark plugs, seat-type spark plugs, pole-type spark plugs, and surface-gap spark plugs.
The replacement interval for most original spark plugs depends on the vehicle model and driving habits, unlike tires which have fixed intervals. If you drive a regular family car from common brands like Toyota or Honda, the original spark plugs typically last about 3 years or 30,000 kilometers before needing inspection and replacement. If you frequently encounter stop-and-go traffic in urban areas, the spark plugs will wear out faster and may start causing issues around 20,000 kilometers. If not replaced, the engine may misfire, fuel consumption will noticeably increase, and you might experience shaking during acceleration, making the car feel underpowered. New car manuals usually provide specific recommendations—for example, my Ford manual suggests replacing them every 40,000 kilometers. Don’t overlook this small component; it affects the overall health of the engine. Regular maintenance keeps your car running smoothly and saves you money in the long run.
From a material perspective, there are significant differences in spark plug lifespan: standard copper-core spark plugs require more frequent replacement, typically every 20,000 to 30,000 kilometers; while premium platinum or iridium spark plugs can last 50,000 to 80,000 kilometers. Failing to replace spark plugs leads to reduced ignition energy, incomplete engine combustion, decreased efficiency over time, increased fuel consumption, and compromised power output. You can perform simple checks yourself, such as listening for crisp engine sounds during startup or observing idle vibration. If you experience sluggish acceleration or excessive emissions while driving, it's time for replacement. The replacement process isn't difficult, but ensure you select compatible models - long-life spark plugs are worth the investment.
