Originally Posted by JCL

What usually causes rapid wear on the inner edge of the tire is toe-in, the tires being pigeon-toed and not pointing straight ahead. This is also adjustable. If the tire is pointing inwards a few degrees, but is forced to roll straight (in line with the vehicle), then both the inner and outer edges are continually slipping (skidding), only the centreline of the tire is rolling without slipping. Both inner and outer could theoretically wear, but the inner tends to wear more, due to the negative camber. Fix the toe-in, to the minimum of the spec that BMW publishes, and you will often get much better tire life.

With wider tires, the toe-in problem is amplified. Also, sport tires often have softer compounds that wear faster anyway.

Only trouble is that you can't see the toe-in (the vehicle is in the way) so you will still get discussion about the negative camber, which you can see easily.