I know it seems silly in mid July to be thinking ahead about winter tires, but the Bridgestone summer run flats that came on our CMSA4 won't cut it for our winter needs as we often take ski trips to northern New England. When our car first arrived earlier this year I had noted that no run flat winter tires were available in any size that would fit the 18 inch Turbofans we ordered with the car. Tirerack is now showing Pirelli Sottozero runflats in the 225-45-18 size, in both H and V speed versions, reasonably priced at $239. While I usually don't like the stiffer ride of run flats, the ride of the Bridgestone summer run flats that came on the CM is tolerable (in our opinion) as we did not order the sport suspension (we previously had an R53 with sports suspension and runflats, and the ride was nothing short of BRUTAL), and based on our experience with the exact same summer and winter tires on our X5 with 20 inch wheels, I would expect the Pirelli winter run flats to have a somewhat softer ride versus the Bridgestone summer run flats, with a somewhat noticeable tradeoff in handling. While there's little doubt I would like the ride comfort of non run flats on the CM, I'm now leaning toward the winter run flats as I have this nagging picture in my head of my GF being stuck in a winter storm with a flat tire, and at least the price being shown by Tirerack is not in the crazy range. With all wheel drive we could probably get by with all season tires, but in my experience there's a big difference in the winter weather capability of winter tires versus all seasons, not only with traction, but also with snow, ice, and slush braking. Last winter I was so impressed with the winter tires on the X5, especially given that we used the very wide OEM sizes, 275-40-20 fronts and 315-35-20 rears (love the look of the big wide 20 inchers on the X5).

 

One correction to the above...the winter run flats for our X5 are Pirelli Scorpions, not Sottozeros.

 

finally another person who knows the advantage of winter tires. Now the question should we run them year around ? I know all the hype for the nearly missing side wall and larger dia. wheels. I see little need for any of this stuff myself. The perfect winter tire is one that is desinged for use in summer also. ( I don't see the CM all4 as a race car anyway) One misconception about wide winter tires is they are not so good in snow. The narrower the better around here when it gets deep.powder. I love Nokia's from Finland, very popular in the Northern Tier....and Canada. We run them on our heavy equipment, forest harvesting machines ( standard on JD ), and just about anything else. best tire I have ever owned, and I thought Michelin was always the way to go. Another thang, don't worry about your flat tires in winter. As I always say, where ever you go, you are never further away than a rollback. ( I drove back from Alaska with one flat and a can of fix a flat, over 3,000 miles in a 1938 Packard coupe convertable Super eight. and they were tube type ! )

 

Feel free to call me indecisive, but I'm now probably going to go with the new Michelin Xi3's (non run flats) based on what I've been reading about them. Part of this is because it seems like every few days I read a new post on this forum from someone else who has glowing comments after ditching their run flats. I also like that the Xi3's are going to be available in 225/50/18 as I'd like a bit more sidewall to protect my rims from all the potholes here in the northeast. Tire Rack is showing them in this size for $193. I will admit I've never met anyone with Nokian winter tires that did not rave about the winter traction.