Spark Plugs: lifespan, maintenance and replacement

Typical lifespan: 30,000–100,000 miles.

Maintenance schedule

• Inspect spark plugs — Every 30,000 miles
• Replace copper plugs — Every 30,000 miles
• Replace iridium/platinum plugs — Every 60,000–100,000 miles

Signs it needs replacing

• Engine misfires or rough idle
• Poor fuel economy
• Difficulty starting the engine
• Lack of acceleration
• Check engine light on

Tips

Iridium and platinum plugs cost more but last 2–3× longer than copper. Always gap plugs to spec.