The only reason you felt like they were better was because your stockers were more than likely meant for 90% asphalt conditions and had shit tread on them. Your newer mudding tires obviously have a much deeper tread pattern which will increase grip, but a narrower tire will ALWAYS be better in snow on regular roads. If you tried your exact same tires in different widths you would see for yourself. Thats why the BMW X5 sucks in snow, the rear wheels are like a 10 or 10.5 inch wide, so they get almost no traction.