Ok, my 2cents. R4's or R1's go nowhere in snow/ice without chains. Learned this from plowing much big snows here in Upstate NY. The mud I have here it also makes little difference between R1's or R4's as once you start digging in and spinning you get stuck no matter what especially if you get stuck on the frame. Maybe a little advantage to R1's but R4's float better wet/mushy ground. Plowing ground R1's advantage but loaded R4's have no problem. Pushing large piles of brush/trees on dry ground R1's better.