How Many Miles Should Spark Plugs Last?

How Many Miles Should Spark Plugs Last? When your engine is functioning correctly, spark plugs should last between 20,000 and 30,000 miles. The U. S. Federal Highway Administration clocks Americans’ average annual mileage at 13,476. Break this down into spark-plug life expectancy, and it comes to between 1. 5 and 2. 25 years. What are … Continue reading How Many Miles Should Spark Plugs Last?