20's on E550 Coupe
FRONT
20X8.5 et 42
245/35/20
REAR
20X10 et 48
285/25/20 or 275/25/20?
But, IMO, there will be more issues with fitting tire sizes you provided on coupe, than with the wheels.
Oem diameter for front is 25.3" (235/40-18). If you're palnning to run 245/35-20 on front - its 26.8" or full 1.5" over stock - I doubt that it will fit at all. Generally it is not a good idea to go over an inch from Oem, or you'll risk running into fitment and drivability issues. If you're planning to go with 20s, then I would use 255/30-20 front (26" diameter) max, 285/25-20 rear (do not think 295 will fit on coupe - it has less room than sedan). Good luck with whatever you decide.







