We do not have real snow here in Aus but I still run Nokian WR G2 235/55R17XL for Winter and Pirelli Scorpions for summer. ie two sets of factory 17inch rims (one set from eBay and well priced). I expect the Nokians to last a long time as they only get 3 months service per year.

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X3 E83 2006 3.0d