When should the spark plugs be changed on e320?

On a Mercedes-Benz E320, spark plugs should typically be changed every 60,000 to 100,000 miles, depending on the engine type and driving conditions. It's important to consult the owner's manual for specific recommendations related to your model year. Regular inspections can help identify any issues, and if you notice symptoms like rough idling or reduced fuel efficiency, it may be time to replace them sooner.