towing ?
Yeah, I don't know about that trailer weight increase Mike. I don't think our 20 inch tires are rated to handle that weight like a truck tire is. I think they are 'P' series. Yeah they are, I just went outside to look. P is for passenger so they don't have the sidewall strength like a 10 ply 'E' rated tire.
If You live in flat land areas, you maybe able to get away with the heavier load. I wouldn't want to stress my QX with that weight.
I have a Outback TT 21 ft but I have a CTD Dodge Ram 2500 to pull it. It does an excellent job towing the trailer with reserve capacity. It's safer.
It could be pulled by my QX but I live in the Appalachians and I am not buring up my transmission.
My advice is, get you a Diesel truck or an older diesel Ford excursion if you have a large family, and use that to pull a larger camper. Your Tires on a diesel truck will be stronger and and have the capability to handle the load. The power-train will have reserve towing capacity and easily to the Travel trailer. By not moving to the upper limits of the QX towing capacity (on paper) it will be safer for you and your family,, just saying.
Bounce more questions, if you have any, I like talking towing and such: )
Have a good one Parrott