ADias said:
RC: why do you think you experienced what it seemed a somewhat erratic PSM intervention? could you think of the road conditions and explain the behavior or was that a system failure?

Also... why did you pick 19" rims instead of 18" for your winter tires?

The PSM can't beat physics. It was pretty slippery and the car just slipped with all four wheels at the same time, this is probably the reason why the PSM didn't come on.

Regarding the 19'' wheels: I don't want to drive my 997 in snow, I just wanted to have the same looking wheels with winter rubber to provide a much better grip at low temperatures. And this is where the rubber mixture counts, not the size. Or course 18'' and narrower tire sizes would have been better for snow/ice driving but I drive my 997 mainly on drive or slightly wet pavement. For serious winter driving with snow and ice, I have the Cayenne Turbo.