I've got Xenon headlights and my car has a feature which automatically turns the headlights on at night. Currently I'm hesitant to use the auto-on feature because the headlights turn on when I start the car in the garage or park in the garage.

I know flicking on/off lightbulbs harm them in general, and I don't want to burn out the expensive bulbs. However HID bulbs don't have filaments if I read correctly, so I don't know if they'll burn out for the same reason.

The headlights come on unnecessarily about twice a day if I enable the auto-headlight feature. Will this significantly impact the life of the bulbs?


I'm no expert, but I have the same setup in my car. I had to install a capacitor to give the HIDs constant power so they wouldn't get power at 60Hz. However, they do turn on and off once in a while, say going through a tunnel.

I haven't had a single issue with them in the last 2 years - since they were installed. As long as they have proper power when they're needed, I don't think it's a big deal.

| improve this answer | |
  • These are factory installed so I'm sure they're installed properly, just concerned about the longevity. The car's six years old but I'm not sure if the lights have been replaced. – Ben Brocka May 22 '12 at 18:29
  • 1
    They shouldn't ever need to be replaced - in the lifespan of the car. That is one of the key benefits of HIDs - they don't get that thermal shock wear that ordinary bulbs get. – Rory Alsop May 22 '12 at 20:47
  • @RoryAlsop Hm, really? So my 6 year old bulbs should last quite a while still for example? – Ben Brocka Jun 4 '12 at 20:38
  • Definitely! My garage was astonished I managed to kill one- turns out I caused it by damaging a casing that allowed water in, which then froze at minus twenty! £600 for a new one :( – Rory Alsop Jun 4 '12 at 20:47
  • My Audi needed a new pair at 100k (eleven years) at £600 each. UK roads may not have helped, as they ended up going out whenever the car went over a bump. However the Audi dealer said that 2006 xenons had that sort of lifespan, and even showed me a technical note. – Andrew Leach Mar 28 '19 at 21:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.