The Excursion has 265 "E" Perelli Scorpions, which were on it when I bought the truck in March. When I tow, I run them at 80 psi.
My previous tow vehicle was a K2500 crewcab short bed. I towed my trailer over 25,000 miles with that truck; first on 285 "E" Toyos that lasted less than 25,000 miles, then with 265 "E" Michelin's. On both sets of tires, the trailer towed super in any condition, even 50 mph Kansas crosswinds. It didn't matter if the hitch height was a little high or a little low. I never used the cam part of my Reese dual cam hitch. I connected the weight distribution bars directly to the snap ups with the chain.
When I was experimenting with the new Excursion, (with suspension mods), I found using only the chains was not enough to eliminate the "truck suck" that occurred when being passed or passing anything larger than a mini-van. I installed the cams and that helped some. I tilted the head back more, and that helped. I downsized from 1200# bars to 600# bars, so I could get more bend in the bar, and that helped a bit more. I installed "E" tires on the trailer, and that helped also. But the rig still wiggles when I get passed or am passing SUV’s and tractor trailers.
I am thinking that the loss in wheel base, going from the crew cab to the Excursion is part of my problem. If not all "E" tires are made equal, (a statement I do not know to be true), I am hoping that a stiffer sidewall might be part of the solution.
I have no proof and I may be wrong, but until shown otherwise, I tend to believe that some tires might have thicker sidewalls than others; even in the same class.
I have had, and currently run "E" Michelin's on my two Subrurbans, and could not be happier with their ride and durability. I got 88,000 miles out of a set. But before I spend the money to put them on the Excursion, I would like to know if there is a tire out there that would perform better while towing. The Ex is not a daily driver, and I do not care what the ride quality would be empty. I anticipate that when I drop the trailer on the bumper, and load the truck for a trip, the ride will be not be harsh at all.