I have 19s on my E 350 coupe they do make for a harder ride, but with adaptive suspension not too bad, they do crack easily I cracked one of mine MB wanted £600 to replace, phew, the tyer walls are only 35 and 30 so it doesn't take muçh on a pothole. My other coupe came with 18s which were much more comfortable, and looked nice. That said, I did get mine tig welded for £30 at a local metal fabricators, and sold it on for £125 plus postage to a man in Greece. Five spoke 18s look nice imo.mine are 7 spoke amgs came with the car look the part but be aware.