how often should I replace HID bulbs? they're getting less white now... the last time I replaced
them was 4 years ago... for precisely the same reason... a new set of HID bulbs from Philips
(identical to stock HID bulbs) made everything white again.

why do HID bulbs degrade after only 4 years? are there other brands, other than Phillips,
that last longer? (or at least maintain the same color longer)

Thanks!

 

Holy COW! I just started a thread about HID bulbs. I have the original bulbs in my 05 LS. I was wondering if it was time to change them just as a "tune-up". Did you notice that the bulbs were getting dimmer? I am thinking about putting in a new set of phillips 85122+ in my LS, but wasnt sure if it would be a waste. I have had my car for 2 years. I dont know what the output was when the car was new. It would be great if changing the bulb would yield a huge improvement in output. You are saying that after 4 years there was a big difference, enough for you to change the bulbs out? My car is 7 years old.....