In talking to other Subaru owners, I am going to go ahead and get a set of winter tires mounted on their own rims with dedicated TPMS devices. However, that puts me in this quandry. Ive read that even though my Touring has 18" wheels on its all season tires, some people prefer to step down to a 17 because they give more cushion for winter potholes and also cost less. I'm guessing that as long as I go with sizes the the Outbacks with 17" tires come with, I should be good. However, in looking at wheels, I am not absolutely sure how critical it is that I buy only wheels with a 48mm offset, like the Outback wheels have or if it's OK to vary from that number a bit (like a 45 mm?) I'm hoping that somebody who is truly knowledgable can steer me in the right direction.