Interesting, because I just sized up to 225/50R18's, and I'd wondered about the spare and the difference in size, considering I'm almost an inch taller than the stock 225/50R17's. I thought I'd just get a 2015 Legacy spare, but then remembered the change to 5x114.3. When I buy snow tires, I plan to run 255/55R17, which is the same height as the 225/50 R18. I wonder if a full size wheel and tire will fit in the trunk and still allow the liner to lie flat?