4.3k is what most newer cars with hids come with...im getting 5k order them the other day...i checked out the difference from 4.3k-8k and 5k seems to be just about right for me ..but aslong as u stay between 6k-8k u should be good 10 and 12k are way to bright and cause problems for u and anybody else to see a damn thing but thats just my opinion