What is the function of a car spark plug?

[VanSophia]

Function and role of spark plugs: The ground electrode of the spark plug is connected to the metal shell, which is threaded into the engine block via the cylinder head. The insulator primarily serves to isolate the metal shell from the center electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and the center electrode, it ionizes the medium between the center electrode and the ground electrode, generating a spark to ignite the air-fuel mixture in the cylinder. Spark plug replacement interval: Under normal maintenance conditions, replacement is recommended every 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine type, so it's advisable to follow the owner's manual. The following standards can be referenced for maintenance replacement: Platinum spark plugs should be replaced at 40,000 kilometers, standard nickel alloy spark plugs at 20,000 kilometers, and iridium spark plugs at 60,000 to 80,000 kilometers.

[McDawson]

When I was repairing my car, I realized how crucial the spark plug is. It sits right on the engine block, and every time the piston compresses the air-fuel mixture, it creates an electric spark with a 'snap' to ignite the mixture. This pushes the piston into motion, driving the entire engine to run. Simply put, without a spark plug, the engine would be like fireworks without matches—completely unable to ignite. The gap between the spark plug electrodes is critical, set very precisely by manufacturers; even a 0.1mm difference can affect ignition. The electrode materials vary, including copper-core and iridium types, and nowadays, better cars come factory-fitted with double iridium plugs that can last up to 100,000 km. Last time my car shuddered during startup, I found the spark plug's ceramic insulator cracked upon inspection—replacing it immediately smoothed things out. Remember, it's the little hero working silently with every startup and drive.

[VanEvangeline]

As a seasoned driver with ten years of experience, I truly understand the importance of spark plugs. In the four-stroke cycle of engine operation, the ignition process entirely relies on this small component. Every minute and every second, it precisely generates sparks to ensure complete combustion of gasoline. If the spark plug is severely carbon-fouled or the electrodes are eroded, the mildest consequence is sluggish acceleration, while the worst-case scenario is complete engine failure. My most miserable experience was when a cylinder suddenly misfired on the highway, causing the car to shake like a dance machine. Upon inspection, we found one spark plug had been punctured. During routine maintenance, mechanics can assess the condition of spark plugs by examining the combustion chamber with a borescope. It's recommended to inspect them every 30,000 to 40,000 kilometers. When replacing, never opt for cheap alternatives—I always insist on using OEM-matched spark plugs to ensure correct electrode gap and heat range.

[AndrewFitz]

As someone who frequently drives long distances, I pay special attention to fuel consumption and power output, both of which are directly influenced by spark plugs. They are responsible for igniting the air-fuel mixture in the cylinders, and higher ignition efficiency ensures cleaner fuel combustion. I've compared single platinum and double iridium spark plugs, and the latter noticeably improves acceleration and saves about 0.5 liters of fuel per 100 kilometers. A friend's car was burning oil, and the spark plugs were coated with oil residue, resulting in a 30% loss in ignition energy. Many modern fuel-injected cars still use independent ignition coils, and faulty spark plugs can cause coil overload. When choosing spark plugs, pay attention to the heat range parameter—high-revving engines require fast heat dissipation to prevent electrode melting. The key is regular inspection; typically, nickel alloy spark plugs should be replaced every 20,000 to 30,000 kilometers.