I just bought a new set of snows for my 92 525. I looked at them all. The best snow tire bar none is the Nokian RSI. It is a studless tire. They have what are called Rainforest sipes (Thousands of grooves in tread pattern). The Nokian RSI
is a new design this year to replace the Hakkapelleta 2. These tires have a nice soft tread. They have an R speed rating.( Who drives over 100 in the winter? LOL). I had them out and ran them at 70mph on packed snow and they were glued to the road. They are amazing!!!!JMHO