[IS+1]

I just wanted to share that after much consideration, I decided on Michelin X-Ice 235/45/18 (square set up) mounted on TRMotorsports C4 wheels from Tire Rack. This is not a tire size which Tire Rack could guarantee would fit the M2, as the recommended 18" size is 245/40/18.

However, I took a calculated risk and am glad I went with this size, for the following reasons:
1) narrower tread width vs 245 should theoretically allow for better bite in deep snow
2) the overall diameter of this tire is 26.3", which helps the tire fill up the wheel well better than the 245/40/18 size, which has a 25.7" diameter and therefore leaves more fender gap compared to the stock summer tires
3) slightly taller sidewalls will allow better protection from winter potholes

I am happy to report that despite the front diameter being larger than stock, I have no clearance issues (I am running stock suspension).

I know some of you may say that the narrower tread and taller sidewall will make for much flabbier handling, but if you had to deal with winters as shitty as I do, that would be the least of your concerns.

I went with square set up as always because during my last 13 years with RWD cars, I've found that even with a less aggressive driving style in the winter, the rears wear significantly faster than the fronts, so this allows for rotation - a big plus for me.

I also switched to Michelin X-Ice after being a loyal Bridgestone Blizzak user for the last 13 years, in hopes that I would get similar levels of excellent snow traction but with more treadlife. Time will tell if this was the right move.

Anyhow, I hope this tidbit of information is helpful for those of you who are still on the fence about what size winter tires to buy.

Drive safe this winter!

[ZPrime]

I did nearly the same thing, but I went down to the 18x8 MSW type 77, and used 225/45 rubber. This is actually only a few mm larger than the recommended winter setup, so I'm not very worried about clearance, especially since it's even narrower.

The Michelin XI3 was the runner up in Car & Driver's winter tire test back in 2015 (the most recent one they performed), and the Blizzaks were actually ranked 4th. #1 was Nokian Hakka R2, and #3 was a set of Continental WinterContact something something something, surprisingly performed better than Blizzak WS70 in their timed tests.

[IS+1]

Wow, you went even narrower than me... I respect that!

[ZPrime]

Lake effect snow is no joke, and this is my first RWD car in snow... But I was using the same width / setup on my TTRS and had no problems.

I figure with XL tires I shouldn't really have a weight / load problem on them even though they are rated a little lower, weight-wise.

I just hope I don't get stuck or perform unintentional donuts or dorifto.

I'm jealous of your rear seats though, I want the 40-20-40 setup! Would come in handy if I ever started playing hockey again...