I have a 97 M3/2 with new Pilot Sports (<2k miles) on the rear and the old MXX3's on the front with 10% tread left. Question is, I would like to replace the fronts with new Pilot Sports but they are about $230 a piece and I can get Dunlop SP 9000 for about $180 each. They are both similar tread patterns and wear characteristics. I just wonder if it would be very negative on the handling characteristics to mix tires? The SP 9000 also have a 280 wear rating vs 220 for the Michelins.