20" Monarch Euro 63RS - Rubbing Issues?
So on the front of a W211 E55/E63 you have:
18" stock tire size = 245/40/18, 25.72" diameter
19" wheel needs a 245/35/19 tire, 25.75" diameter
20" wheels needs 245/30/20 tire, 25.79" diameter
A 245/35/20 tire has a diameter of 26.75", or over 1" taller than stock. Yeah, it will rub.
The other tire consideration is to make sure you only use tires that have an "XL" load rating. Again, that's what the factory specified, and it's even more important when you're going with an extremely low profile tire like a 30 series. Our cars are heavy; the tire load rating is a safety factor.

Has anybody else had this problem? If so, what can I do about it? What size tires are you guys running on the staggered (20 x 8.5 and 20 x 10) fitments? Help! Thanks...
The Best of Mercedes & AMG


Seriously though that vendor should have known the tire size closest to factory. Going an inch or more larger in rolling diameter on a car like this is no good especially when you are lowered...at all..or have a suspension that has settings that lower it manually and at 75 mph.

Thanks for the info, though. One additional question... the rubbing seems like it's occurring in the middle of the tread. If it rubs, will the groove in the middle of the tread create additional issues?
DO NOT DRIVE WITH A 245 35 20 up front, If you put the car in the raised setting and look at the top of the tyre you will see how close the tyre is to the thread bolt of the upper arm that conects to the hub (about 2-3mm).
When you use the brakes and go over bumps it pushes up against the bolt, that is why you are getting the line in the middle of the tread. I ground about 5 mm of mine with the dremel and this stopped the problem.
goodluck



