I run 20" studded snow tires in the winter and have always gotten through anything I encountered. In Oregon we are required to carry tire chains when crossing the mountain passes. I carried cable chains to comply, however I could not actually install them. Have traded the cable chains for AutoSock "chains." If I ever encounter a need I could try them. But, if studded snow tires and 4 wheel drive are unable to get me through I'll turn around and try another day. www.autosock.com