Theres probably been a lot of dicussion about this in various other threads, but I couldnt find one directly about the subject. Having done a lot of suspension and engine work on my z3m i found that the recommended tyre pressure of 34 psi left my wheels spinning in third, so Ive dropped down to 31psi for a compromise of speed and steering sharpness. What are other doing? Im running Michelin Pilot Sport Cups which is a firm tyre.