is there any difference between oem bmw hid ballast and the aftermarket ones

[shawn01]

just had a question about ballasts, are the oem ones on bmws the use d2s any different then the aftermarket ones? say i wanted a 8000 k bulb if i just buy a new set of d2s would it be the same then aftermarket ones with a h7 bulb that have a 8000 k rating.

[shawn01]

just went and got d2r lights 8000k for my original ballast used in my 2001 x5 and they blinked a few times and shut off, so i called and found out that with these oem ballasts anything over 6000k they wont really work right, so got to get aftermarket ones