How Many Grades of Spark Plugs Are There?
2 Answers
Currently, spark plugs come in a variety of material grades, each with different performance characteristics and replacement intervals. They can be broadly categorized into: nickel alloy spark plugs, platinum spark plugs, iridium spark plugs. From a manufacturing perspective, there are thick electrode spark plugs, needle electrode spark plugs, double platinum spark plugs, iridium-platinum spark plugs, double needle iridium spark plugs, etc. Function of Spark Plugs: The material of spark plugs usually refers to the electrode material. Currently, platinum and iridium spark plugs are considered the best. Platinum and iridium are precious metals with excellent resistance to high temperatures, high pressure, and corrosion. Using these materials for spark plugs can significantly extend their service life, though they come at a higher price. Replacement Intervals for Spark Plugs: Nickel alloy spark plugs should be replaced every 20,000 to 30,000 kilometers, nickel-yttrium alloy spark plugs every 30,000 kilometers, platinum spark plugs every 40,000 kilometers, double platinum spark plugs every 60,000 kilometers, iridium spark plugs every 80,000 kilometers, and platinum-iridium alloy spark plugs can last up to 100,000 kilometers before needing replacement.
Spark plugs can be categorized into three or four grades. The most basic ones are nickel alloy, costing around 20 yuan each with a lifespan of 20,000 to 30,000 kilometers. Last time I saw a mechanic remove them, they were completely covered in carbon deposits—these are suitable for temporary use in older cars. The mid-range options are platinum plugs: single platinum costs about 70-80 yuan each, while double platinum is slightly more expensive, lasting up to 60,000 kilometers and offering quicker starts. I often drive on highways, so I use these. The top-tier ones are iridium plugs, featuring fine electrodes for exceptionally stable ignition—standard for performance cars. NGK’s iridium-platinum plugs cost over 200 yuan each and can last 100,000 kilometers. However, don’t blindly go for the expensive ones; using iridium plugs in small-displacement cars is just a waste of money. The tuning community also has ruthenium alloy spark plugs, priced at 400-500 yuan each, but ordinary cars can’t even utilize their potential.
