I just bought new rears for my XF. I don't get much snow/ice so I bought Falken 452's. Where did you tires wear out? Mine were very worn on the inside 2-3 inches and the rest of the tire had much more tread left. I mention this because if your tires are wearing the way mine were, you need to do something about the camber. Otherwise you will wear out any tire you get prematurely no matter how much you spend. I have been told by some that the most wear you will get is about 15k miles and that the inside wear is normal. I believe you should be able to get more miles and that the wear should be more uniform. Good luck!