You should generally change your spark plugs every 20,000 to 150,000 miles depending on the quality of the plugs and the vehicle. Most newer vehicles have longer-lasting spark plugs that may only need replacement closer to the higher end of that range. Specific recommended intervals vary by car model; for example, a Toyota Corolla typically requires spark plug replacement around every 60,000 miles, while a Toyota Sienna can go up to 120,000 miles before needing new plugs. Signs you should change your spark plugs sooner include:
- Rough idling or engine misfires
- Slow acceleration or sluggish engine response
- Difficulty starting the engine
- Check engine light turning on (steady or blinking)
- Poor fuel economy
If your car runs fine and you haven't reached the recommended mileage interval, you may not need to replace them immediately. However, spark plugs are usually best changed as part of scheduled maintenance to avoid engine performance issues or damage to other components like the catalytic converter. For many cars, a common recommendation is to replace spark plugs around every 30,000 to 90,000 miles, or roughly every five years. Always check your vehicle owner's manual for the manufacturer's specific recommendation for your car model. If you are unsure or your car shows any signs of trouble related to spark plugs, it may be wise to have them inspected or replaced by a mechanic.
