Just curious as I don't have a P90D, just a classic P85. I got my car with the 21s with Continental DW. After 25k miles with those I decided to give the 19s with the stock Michelins a try. They break traction well under full throttle on launch, and have much less grip in the corners. Stopping distance is noticeably longer. The steering also feels more sluggish and not quite as sharp. It's all basically what I expected going from high performance summer to all season tires, but I think the car really shines with the summer tires.
Anyway:
My question is since my car shares the same rear drive unit with the P85D and P90D, I'd assume they'd also be able to break the rears free pretty easily if equipped with the same tires. Surprised to see a number of reports of "no problems with traction with the 19s". Is the torque split with the AWD tuned so that the rear motor doesn't produce enough power to break the rears free or does it have different traction control? What's the story?