With a different rear axle ratio, you could tow in a higher gear. With what you have, you will tow in a lower gear and end up traveling the same speed. But your rpm will be higher, most likely. Generally I'd bet a 3.55 would let you travel mostly in 6th gear while towing more or less on the level. But your ratio will probably make the transmission call for 5th. The axle difference is about 10.5%, the gear difference is about 29%, so your engine would be running about 18% higher rpm to achieve the same highway speed in that scenario.
However, what the tranny will call for depends upon your trailer's aerodynamics and weight. If you choose a rounded, aero trailer like a Scamp, Casita or similar, you will have an easier time of it and may not need that higher gear. Or a popup, even better. You will definitely want to avoid the 8' wide, high and boxy trailers. And if you were planning to travel through the mountains, you should want to keep the loaded weight below 3000 lb IMO.
My Highlander's engine has similar HP and torque (a bit less, but also a bit lighter vehicle too) to the 3.6. Although the 3.6 does have a flatter torque curve, which is helpful. My TT is 7' wide and 99" high. 2700 lb loaded. I have been through the Rockies a couple of times with it, and now I'm planning to replace it with a Grand Cherokee and 5.7L. It can be done, but slow going up the grades does get tiresome after a while.
Mike G.
Liberty is meaningless where the right to utter one's thoughts and opinions has ceased to exist. That, of all rights, is the dread of tyrants. --Frederick Douglass
photo: Yosemite Valley view from Taft Point
