I was wondering if anybody out there has had any issues with shock tower or fender clearance running a 255/35-20 on the front of their SL 550 2013 or newer. I have a 255/35-19 on the front with 8.5 inch width rims right now and I am wondering if the diameter increase will create a problem on the same width of rim in a 20 inch size. I know that the wheels offset can change things if there is much of a difference between the two rims, but I have multiple sets of spacers that I can adjust with on a given rim. I could also drop down the profile to a 255/30, but that also limits tire choices by quite a bit as it just isn't that common of a size and I would rather not go that route if at all possible.

 

Take a look at the link below; it's a really helpful guide on wheel fitment and spacing/offset. I may be mistaken, but wasn't there a 20" option for your car from the factory?

Wheel Fitment & Spacing Guide

 

From what I have seen on the factory websites there was no OEM 20 inch option on the SL 550, just 18 and 19 inch size rims in a variety of styles.