Spark plugs are a crucial component of a car engine's ignition system, typically with one spark plug per cylinder. The performance of spark plugs determines the engine's efficiency and overall performance. Many car owners nowadays overlook the maintenance and replacement of spark plugs. On the road, the engine may experience severe shaking with a "clunking" sound; fuel consumption may sharply increase, burning oil as if it were water; and the accelerator may feel underpowered. In such situations, one might wonder if the car is about to be scrapped. In reality, these issues could simply be "minor" problems caused by faulty or overworked spark plugs.

Like other automotive components, spark plugs are high-frequency consumables. However, unlike engine oil and air filters, although they have a fixed service life, their aging process is invisible because they operate inside the engine.

How can you tell if a spark plug is aging?

Signs such as difficulty starting the engine when cold, vehicle shaking, increased carbon buildup, and high fuel consumption may indicate aging spark plugs. If your car fails to start completely, it might not be due to the battery but rather the spark plugs.

At this point, we need to replace the spark plugs. What should we pay attention to when replacing them?

1. How often should spark plugs be replaced?
   The material used in spark plugs plays a decisive role in their replacement cycle. The mainstream spark plugs on the market today include copper-core, nickel-alloy-core, platinum-core, and iridium-core spark plugs.

• Copper-core: Replace every 20,000–30,000 kilometers.

• Nickel-alloy-core: Replace approximately every 40,000–60,000 kilometers.

• Platinum-core: Replace every 80,000 kilometers.

• Iridium-core: Replace every 100,000 kilometers.

1. How to determine if the spark plugs in the engine are working properly?
   The most direct way to check the health of a spark plug is to remove it. If the electrode and insulator are light yellow, it indicates the spark plug is in good working condition. If there are black deposits on the electrode, it suggests an issue, possibly caused by "burning oil" or an improper air-fuel mixture ratio.

When replacing spark plugs, pay attention to some details.

First, you must choose spark plugs that match your car's specifications. Second, professional tools are required.

When removing spark plugs, work on one cylinder at a time. Do not remove and install all spark plugs at once, as this could allow dirt to fall into the cylinders.

During installation, the most critical factor is torque. Spark plugs of different sizes require different torque levels. If the torque is too low, it can cause oil or gas leaks, affecting engine performance. If the torque is too high, it may lead to spark plug damage or twisting.