I have a 1/2 ton Chev Silverado pickup with which I pull a 30 foot travel trailer. I believe that I am within all the parameters as far as towing guidelines. I still get the sway out on the Interstate when the semis go by. I have read on this forum previously several times about people putting on LT tires with Load range E and they have reported much improved towing results. My pickup has P265/65R-18 tires and when looking for LT tires in this size, I find them almost impossible to find. Dealers tell me that almost no one puts these on a 1/2 ton pickup, so that's why they are hard to find. Anyone have any suggestions?