Xenon HID bulbs can last longer than 3000 hours. But because the output decreases during their lifespan, advice is to change them sooner.General advice is to replace them around 1000 hours of use. With 1500 hours of use, the output can be decreased by around 25% percent, so at that moment you have already lost quite a lot of output in comparison with a new bulb. So when doing a retrofit for more light output/performance it is also important to change the bulbs in time.