SHELBY GT 350 Member
Joined: Jan 2011
Location: Central Massachusetts
I don't know the offset specs for the S550 but 40 does sound a bit on the high side perhaps
coop, are you saying you already have the wheels and the wheel/tire is close to the strut? if so, how close?
on my fronts I can just about get my fingers between the tire and the strut and and top strut bolt, but I have never had a problem with any actual contact
if 40 is too close, 45 will be worse and probably hitting, because higher offset pulls the wheel inward under the car; for more clearance on the strut you need less offset, but the trade-off is the wheel/tire will stick out of the wheel well more
| 2010 GT coupe | Daily Driver with some Steeda and GT500 take-off stuff for the occasional track day