sidney61199 said:
EricR, who's standard is it? Tire company, state, goverment or an independent organization? I've never lived in a place bad enough to worry about a sever winter. Also are the ones your talking about all season? You have to remember Pirelli's are made in Germany (I think so) home to the autobahn which goes through some regions with some real harsh weather. I would think that a tire that is stock on all Porches (<spelling?) is pretty good.
Well I'm no expert on this, just a big fan of Nokian tires! But you raise an excellent question, so I did a quick bit of research on the matter.
Here's a link I found explaining the difference between the M+S and severe snow service designations, and the ASTM testing procedure required for the severe service rating:
HowStuffWorks.com - Snow Tires .
In a nutshell the severe winter service standard was created by the tire industry and requires on-the-snow testing to a specific stantard as defined by the independent ASTM (American Society for Testing and Materials). It has been accepted by several government entities - I'm positive about the state of Oregon and Canada. IIRC, New York and several countries in Europe are a part of it also.
Yes, the Nokian WR is designed to be used in, and is called "all-season", but is the only such tire to have the severe service qualification.
Here in the Seattle area I don't worry about severe winter weather either, so my Focus will stick with the stock P-6's for now (knock on wood that it won't get bad enough I have to use chains). However, for skiing and our annual winter trecks to places like Idaho we take the wife's van and for that we run the Nokians!
Driving in the snow can be a blast, and it can be quite scary -- so i'm not sure if I should be happy or sad for you, living where this is not a concern.
I too would guess that any tire comes on a porsche would be quite a good tire. FYI, a quickie search of "tires" on the porsche web-site listed links to wheel and tire options they sell and in all instances (except their 4x4) they offered both summer and winter tires. I didn't notice any all-season tires, so I would venture a guess it's not something they use.
Lastly, though I couldn't find anything quickly about here in the US, in Canada the Nokian WR All-Season comes with an 100,000 kilometer tread-wear guarantee!
Regards,
EricR