anyone have recommendations for a WINTER 21" tire for my G63. Tirerack has several options including Pirelli scorpion and Continental wintercontact. Also option is bridgestone blizzack but only Run Flats. Not sure i want those?? Any thoughts on what to do??

About your only choices in 21" are Pirelli and Hakkapeliitta, so it comes down to a coin toss. If you're OK with changing the aspect ratio a bit, there might be a few other choices (assume you've been looking for 285/45's). I bought a set of 20" wheels because of the meager choices in 21".

Pirelli scorpion Winters are good. I've had these tires on my glc63 and Urus. I'm also running them on my winter set for the G63 but haven't used them yet on that truck. 21" on the GLC and 22" for both the Urus and the G63. The stock 21" Michelin Latitude Cross was surprisingly good during the last winter here in NY.