I have talked to Tirerack people and find that because of the Brembo brakes there is only one recommended wheel for winter and that is a 17 X 7.5. They also recommend a winter tire of the same size as the stock tire (235/45-17).

I have always felt that a narrower tire works a bit better in the snow and on my S-4 went to a 205/55-16 size. But, restricted to 17 I am wondering if something like a 215/50-17 would work. The rolling circumference is about the same, minor difference, but the load capacity is less. Not sure if it matters with the TL weighing 3465#.

I am looking at another set of Pilot Alpins or Pirelli 210s...or ???