Spark Plug Calculator

Plug life depends on material

Copper plugs last roughly 20,000–30,000 km, platinum 60,000–80,000 km and iridium up to 100,000 km. Modern iridium plugs are expensive but last far longer.

• Replace all plugs at the same time
• Use the correct gap for your engine
• Copper and iridium must not be mixed in the same engine set
• A worn plug shows up as rough idle and higher consumption

Misfire symptoms

A misfire (engine shakes, loss of power, check engine light with P0300–P0304 codes) can come from the plug, the coil, the injector or fuel quality. Read the OBD code before replacing anything.