hi, i'm running 245 40 18's front and 265 40 18"s rear. that's stock. rims are 81/2 j front and 9 j rear. i saw a killer set that are 81/2 all all around. i assume that i would have to run 245 40 18's all around with those rims. how would that effect performance and computer settings? would i be able to fit the 265 40 18's on the 81/2 rims?

What are the offsets of the rims your looking at? That is a more important first question.

the offsets are correct 44 all around.

offset seems high, if im not mistaken these will not clear brakes without spacers. Plus the will sit more inside the fender. do you have the AMG brake kit?

no, i have a cl600 and 44mm offset all around is correct.

bump for an answer.