SL55/63/65/R230 AMG: SL63 Tires
Front 255/35 ZR 19 (96Y) as per factory
Rear 285/30 ZR 20 (99Y) but factory indicates 285/30 ZR19 (98Y)
From Owners Manual




these are a staggered set with 19 front 20 rear.
may or may not be standard for your car. Otherwise, the front is right, the rear should be ok. Do they rub anywhere? If not, no problem.
If you can remove one of the rear wheels and check the part number, should offer some clarity.









