How long do spark plugs last?

The length of time that spark plugs last depends on the number of miles driven and the type of spark plug a vehicle has installed. Spark plugs are typically changed every 45,000 miles, but some spark plugs are advertised to last as long as 100,000 miles.

Changing spark plugs helps to maintain engine performance, improve cold starting, and reduce the risk of catalytic converter failure. Some common car problems such as carbon deposits, ash deposits, oil deposits, running too hot, detonation, mechanical damage and high-speed glazing can be identified by the visual appearance and condition of a vehicle's spark plug.