How Many Types of Spark Plugs Are There?
2 Answers
There are numerous types of spark plugs, varying in materials such as nickel, platinum, and iridium alloy, in forms like single-tip, double-tip, and four-tip, and in heat resistance with high-temperature and low-temperature differences. Below are specific methods to determine the condition of a car's spark plugs: 1. Observe the color of the spark plug's appearance: Severe erosion, blistering, black streaks, cracks, or melted electrodes indicate that the spark plug is damaged and must be replaced immediately. A sooty black color suggests the wrong heat range was selected or the air-fuel mixture is too rich, with oil contamination. 2. On-vehicle inspection: Spark test—remove the spark plug and place it on the engine block, then test for spark using a high-tension wire. If there is no spark or a weak spark, it indicates the spark plug is leaking or not functioning. Short-circuit test—with the engine idling, use a screwdriver to short-circuit each spark plug one by one. Listen carefully for changes in engine speed and sound. Significant changes indicate the spark plug is functioning normally. If there is little to no change in speed or sound, the spark plug is in an abnormal state.
As a car enthusiast, I've worked with spark plugs while helping out at repair shops and found there are far more than just a few types. The main classifications include materials: copper ones are the cheapest but have a shorter lifespan; platinum ones are more durable and suitable for daily driving; iridium ones offer the best performance with quick response but come at a higher price. Heat ranges are divided into cold and hot types—cold types have smaller numbers like 5-6 and suit high-speed engines, while hot types have larger numbers like 8-10, which are fuel-efficient but prone to carbon buildup. Each car model's engine requires a matching type; otherwise, ignition issues or sluggish acceleration may occur. I've also noticed different brands have specific models, such as Japanese cars often using NGK copper-core plugs, while American cars prefer iridium ones. When replacing spark plugs, always follow the manual to choose the correct type—never mix them for convenience, or the engine may shake. Regular checks can prevent roadside breakdowns, and I believe replacing them every 30,000–50,000 km is the safest bet.
