How Many Types of Spark Plugs Are There?

[OJeffrey]

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.