How often do you change glow plugs in diesel engine?

Glow plugs typically last between 40,000 and 60,000 miles. However, the manufacturer recommends changing glow plugs every 100,000 miles or so. The life expectancy of glow plugs is heavily influenced by the quality of the fuel, climate conditions, and driving patterns. For maximum performance and to avoid premature failure, it's generally advisable to follow your vehicle's recommended maintenance schedule and replace glow plugs when needed.