I got my S85 in October last year with the Cyclone rims and the upgraded all-season Michelin MXM4 Primacy. After the first big snowfall, I was not able to get up a very small grade hill that leads to the main road near my house. It was sliding all over and backwards and fishtailing. Had to reverse all the way back to the garage and grab the ICE SUV. After that I immediately ordered snow tires (first tried for Hakka R2s, but they were sold out everywhere, then settled on Blizzak LM-32 from TireRack and installed by Firestone locally). The snow tires made all the difference. I had traction, stability and felt great while driving the whole season, practically until April when temperatures went up. With the amount of snow we had, I felt the investment was worthwhile. These were my very first snow tires. I saw SUVs get stuck and fishtail where the Tesla went through with no problems.