Front you must have less than 32mm offset if going with an 8 1/2 wide rim. If you can only find wheels you like with 35mm offset you can purchase spacers from Eibach like I did. They sell a 5mm spacer for ~ $75 pair. Rear you can go atleast 9 1/2 wide with 35mm offset.
I have a 350 with the AMG PKG and I have 18X8.5 with 225/40 front 30mm offset (5mm spacer makes it that way). Rear is 18X9.5 with 255/35 35mm offset.
I tried the front wheels without the spacers and 8.5" with 35mm offset WILL rub the suspension without a spacer.
In order to not "raise" your car you will need to try to lower your sidewall profile from what I have if you choose to go with 19". Like 35 front and 30 rear.
I running 235/35/19 and 265/30/19 on HRE 845s 8.5 F and 9.5 R...that comes form HRE. They say don't go any bigger than 9.5 on the back. Of course, many in Europe have gone to 10 inches but it sticks out in the pics to me. Not the look I would want...save that for the ricers.
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