It seems to all boil down to whether or not the car has a limited slip differential. Here's another point of view, from reader Brian Innes: "I own a 2nd generation Cayman S manual and live in the Scottish Highlands, which in 2010 had the worst winter for 30 years. I invested in a set of 4 Pirelli Sottozero winter tyres from www.mytyres.co.uk fitted on replica Cayman S 18" wheels from Porsche Shop UK and never got stuck at all in the wintry conditions. On all surfaces from sheet ice to deep snow/slush, the Cayman proved to be an exceptionally well-balanced car with near perfect 50/50 weight distribution and it is the most stable car I have ever driven in slippery conditions in over 40 years of driving. Traction, steering, and braking are all way above expectations. It's a revelation. Oh, and remember to specify the mechanically locking differential (LSD). You'll not be disappointed. It's essential." (The LSD was not initially available on the Cayman so that it didn't out handle the dearer 911, but it did become available later.)