Reality, assuming the trailer has the proper 10-15% hitch wt, assuming the trailer is a single axel, I prefer closer to 13-18% HW. There should be no sway when the trailer is on the interstate doing 60-63mph. IF there is fishtail sway, you need to figure out the how the trailer is loaded. TOO much weight to one side, the trailer will sway. Too little hw, again trailer will sway. too little air on one side or the other by 10-20+ psi, or a standard load vs a 6+ ply tire can cause issues. If it is a dual axle, and the axels are V'd, this needs to get fixed.
The sway or WD bars should be to put on an already properly setup trailer, to give you a bit more breathing room when the unexpected happen. They should not be used to soften or get rid of uncontrollable sway. You may feel the trailer and or TV move sideways to both directions when the bow wave of a semi passes or you pass it. This is normal, bars might keep it down some, I have not found this to be the case. I've felt the same bow wave movement with or without bars.
With the above said, it will take a trip or 7+ to truly dial in the how well you trailer will tow behind your truck.
Marty
Thanks
