Living as I do in the Highlands, winter tyres are essential if your journeys include untreated rural roads, many of which are unclassified in my particular location.
My Gen 2 Macan Turbo is currently fitted with Michelin Alpin 5 SUV N0 rated winter tyres. I tested them on fresh snow covered local roads for the first time today. The roads I encountered had up to 10cm fresh lightly compacted snow. The ambient temperature was -5c.
 
The results were excellent. Winter tyres are not all about traction avant. Steering and stopping grip also crucial. In my part of the UK, winter tyres are most certainly not a con. My life, and the safety of my Macan depend on the contact footprint of the Michelin Alpin 5 tyres. Today, both the car and the tyres passed all tests with flying colours.
 
Brian
   

ignatzcatz
Toward the Winter and colder seasons there is always the big push for the fitment of winter tyres. I believe that unless you are living near the Artic circle these tyres are just a big sales con. If you have good treaded tyres and you don't drive like a loony the difference these tyres make is so marginal as to make no difference whatsoever. If I had the misfortune to have to frequently traverse muddy and slippery byways I would fit real knobbly tyres but actually if I had such journeys I wouldn't use the Porsche, I would buy a Land Rover. My comments apply equally to more regular cars, I wouldn't consider fitting them to my 911 but then I wouldn't drive it down muddy pathways, heaven forbid. A good friend did purchase these winter tyres for his Audi A5 cabriolet and apart from being a bit noisier the difference was unnoticeable although the wilds of Guildford isn't the best of comparisons to the outer reaches of North Yorkshire I suppose.
Anyway I'm not buying any.     

Thanks for that well researched & evidenced post... 🤔 
 
There is a huge amount of research that has gone on not only within the tyre industry but also in independent driving bodies, including Porsche themselves on the role of winter tyres.
 
 
I have lived in Scotland, Canada and rural Wales - as well as London - and driven in all seasons in Europe, and confirm that winter tyres have substantial safety benefits not only in snow & ice but also in dry cold conditions.
Yes if you plan off-road driving “knobbly tyres” (presume you mean AT / MT by that) would be the choice depending on the amount of mud, but that is irrelevant to your discussion on winter tyres which are designed for on-road use. I can also confirm that you don’t have to “drive like a loony” to benefit from winter tyres - have seen and experienced first hand the dramatic effects of cold temperatures on summer tyre grip at low speeds. 
 
In many parts of continental europe it is illegal to drive in winter months without winter tyres, and it doesn’t take much reading to see that even in the absence of snow the accident stats clearly show the effects on safety of cold and cold-wet conditions, where winter tyres have proven significant benefit.
 
A common misconception that you also hold is that winter tyres are only for snow, but in Canada I can confirm that there is a better option of snow tyres for REAL winters, with tungsten studs - I agree there is pretty much no place in the UK where these would be needed other than in unusual extreme circumstances in the Highlands.
 
(Just to lend credence to the above opinions, I am a qualified rescue driver, also with qualification in off-road driving / recovery & training of this, and own a Land Rover which I use on- and off-road, and would pick my Cayenne with winters on it over my Landie with AT / MT’s on it for driving on snowy / icy roads. Also happen to be a Trauma Surgeon so quite familiar with the consequences of poor driving...)
 
To put my perspective in the way you did in your last sentence “Anyway I am buying them...!”