I did the same thing on my 19" Pirelli's. It really annoyed me to replace the tires because of poor wear. I caused the problem by over inflating them. I ran 35 pounds on the last set. This time, I'm running 32 pounds and the wear is much more even. I'm sure someone is going to say you shouldn't because there asymmetrical tires, but I got another 5K miles before I replaced all 4 tires.

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2013 X5 3.5i M Sport
2004 M3 cabriolet SMG