Something else I've found makes a difference (with wheel nuts anyway) is to strike the nut after heating, using a length of pipe of suitable ID to slide over the hex and seat on the flange (eg. 1'' water pipe for 15/16" wheel nuts). If you rest the other end on a jack stand you can take a full blooded swing without fear of injury and bash away to your heart's content, which as we know is always highly satisfying! Unfortunately on this particular occasion I had yet to equip myself with the correct tools, and consequently failed to remove a single wheel nut! However I did succeed in testing to destruction two double hex sockets and a 1/2" drive breaker bar, which sheared off through the actual 1/2" square stub. Returning some weeks later with a 3/4" breaker bar and 15/16" impact socket I had no trouble whatsover, although some nuts required the assistance of the property owner, made possible now by the use of a much longer extension pipe of far heavier gauge, from which both of us could hang our full weight and bounce up and down! With that kind of torque I found it amazing that not a single stud broke, which leads to believe that most of the force required is due not to seized threads, but to seizure of the flange surface on the wheel. That might explain why striking the flange directly can often help, so it may be worth trying with seized rim nuts as well. It certainly can't hurt and can be quite therapeutic, esp. if you upgrade to a sledgehammer!
