Spark plugs should generally be changed every 30,000 to 100,000 miles, depending on the type of spark plugs and the vehicle manufacturer's recommendations. Here are the key details:
- Standard copper or nickel spark plugs typically need replacement every 20,000 to 30,000 kilometers (about 12,000 to 18,000 miles)
- Platinum and iridium spark plugs last longer, usually requiring replacement every 50,000 to 60,000 kilometers (about 30,000 to 37,000 miles)
- Double platinum and double iridium spark plugs can last up to 80,000 to 100,000 kilometers (about 50,000 to 62,000 miles), but vehicles with turbochargers may need checks every 20,000 to 30,000 kilometers (12,000 to 18,000 miles)
- Many modern vehicles recommend spark plug changes around 100,000 miles
- Some manufacturers specify intervals within 30,000 to 90,000 miles depending on the model; for example, a Toyota Corolla may require replacement every 60,000 miles, while a Toyota Sienna can go up to 120,000 miles before replacement
- Signs that spark plugs need replacement include rough idling, slow acceleration, hard starting, engine misfires, poor fuel economy, and the check engine light turning on
Ultimately, the best practice is to follow your vehicle's owner's manual for the recommended spark plug replacement interval, as it varies by make, model, and spark plug type
