How often do you need to change your clow plugs in a diesel engine?

The best answer is to follow the recommendations for maintenance in your particular car's owner's manual. A rule of thumb is every 30,000 miles for standard plugs and 60,000 for platinum or other precious metal plugs.

Don't forget the ignition system's secondary wiring. Worn plugs and damaged wires can cause ignition coils and other ignition components to fail prematurely.