So far I've tried the following on my X:
Michelin - Summer tires (20")
Pirelli Ice&Snow - all year (winter for me) tires (19")
Nankang - Summer tires (20")
As for the best summer tire it's a no brainer between above mentioned....the Michelins are No1 and I've used them in +50 (Dubai) heat and the low 20s Scandinavian summers, no noise, amazing grip and work very well in case of rain.
My current winter tires, the Pirellis, are Very good. The grip I have during heavy snow fall is surreal...I've pulled countless poor souls up the hill where I live (including 4x4s!) These type of tires are not high performers on Ice though but the same goes for any other brand...studded tires are the rulers in this area. I've never had issue with them on ice though...just be sensible and drive with care.
As for the Finish brands mentioned in this thread, they are indeed VERY good. I've had both on my old E36, E39 and E46...look no further if you get them.
The Nankangs....I don't want to talk about it.
