What is the Difference Between Platinum and Iridium Spark Plugs?
2 Answers
The difference between platinum and iridium spark plugs lies in their replacement intervals: platinum spark plugs should be replaced at 40,000 kilometers, while iridium spark plugs need replacement between 60,000 to 80,000 kilometers. Steps for replacing spark plugs: Open the hood, lift the plastic engine cover, remove the high-voltage ignition wires, and mark each cylinder's position to avoid confusion. Use a spark plug socket to remove the spark plugs one by one. During removal, check for external debris such as leaves or dust and ensure thorough cleaning. Place the new spark plug into the spark plug hole, hand-tighten it a few turns, and then use the socket to tighten it further. Reinstall the high-voltage ignition wires in the correct firing order and reattach the cover. Methods to determine if a spark plug is damaged: Remove the spark plug and inspect its appearance. A normal spark plug's insulator skirt and electrodes should appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has a reddish-brown insulator skirt, with an electrode gap between 0.8-0.9mm and no signs of electrode burn. If the spark plug is coated with oil or deposits but is otherwise undamaged, it can be cleaned and reused. If the spark plug is severely damaged—showing signs of blistering, black streaks, cracks, or melted electrodes—identify the cause of the damage, rectify the issue, and replace the spark plug. Additionally, if the spark plug appears blackened as if smoked, it indicates incorrect heat range selection, a rich fuel mixture, or oil leakage.
I've driven regular family cars for over a decade and used both platinum and iridium spark plugs. Platinum plugs have thicker electrodes with better corrosion resistance, and they're more affordable – a set only costs a few hundred yuan, lasting about 80,000 to 100,000 kilometers. They're quite suitable for daily city commuting. Iridium plugs have finer electrodes for more precise ignition and quicker engine response, but they're pricier, costing over a thousand yuan per set. For everyday driving, I think platinum plugs are more cost-effective and hassle-free, no need to spend extra. Spark plug choice should also consider your car's condition – in my older car, switching to platinum improved idle stability.
