Originally Posted by ChitownM3
What, what? The E46 M3 used 225/40/18 fronts and 255/35 rears (subtract .05 aspect ratio for 19s). That results in front and rear tires of about the same diameter. If the specs are true for the E92 version, the rears are larger in diameter. This does not mean anything in particular, it's just a departure that I don't know has been previously recognized. If the diff ratio is lower (which it is at 3.846), the larger tires are offset to some degree in overall drive ratio.