For starters I would never suggest mixing tire types (ie, s-02's with Pilot Sports, AVS, etc......) on an M3. Not only will it affect your handling, it may set off the traction control (if the car is a 96-99 model). As for the sizing a 225/45 is paired well with the 245/40, but the 235/40 and 245/40 do not mix well as far as diameters are concerned. The tire you mention at the bottom of your post is H rated up to 130mph. If you wish to discuss specifics, let me know and I can help. thanks Aaron 800.428.8355 x395