Never had to change mine in 5 years/70 000 miles. You are being careful not to touch the bulb with your hand when you fit it? Skin contact shortens their life. I do get through a lot of rear light bulbs though.What is the normal life of your headlamp bulbs on TD5's iam lucky if i get 2 months from a bulb. Its not that.There no cheap and an absolute nightmare to change when you have lampguards on and a A bar. Does anyone else have or came accross this problem...