Im wondering this because mine are noticably less bright lately. I know halogens dim out over time and was wondering if HID's do the same???? If they do its time for a new set obviously..

all light's dim over time, it just takes longer for some than others, as for how long it would take an HID i do not know.

How old are they? Are they a cheap pair? I don't think they dim. My dad's car ('00) and my moms car ('05) both have HID projectors, and both seem to be the same brightness.

im pretty sure they are a few years old by now. i bought them from a member on here and ive had them for about a year now. they are in a set of projectors and just dont seem to be as bright to me anymore. hmmmm maybe ill have to just suck it up and buy another kit just to test the theory out...

I have read about bulbs "color shifting" after so many hours of use. They get bluer and threfore not a bright.
I have noticed this change on mine.

interesting....they were 8000k to start so i can only imagine it would get worse if they did that

that or it could be a ballast issue with it not putting out the same amount of steady power... the reason halogens dim quicker is cuz they run a completely different way... they rely on a filament to get white hot and glow... HIDs actually make an arc with xenon gas and dont use a filament, very much like a fluorescent bulb

i would try new bulbs first before ballast, cause their cheaper