Originally Posted by LakeSinclair
It's got plenty of towing capacity for most trailers with a rating of > 9000 lbs, but the wheelbase is 131" compared to 137" for a Ford F-250 2-door or 156" for the F-250 4-door. Is there a maximum length above which you wouldn't feel stable?
With an Expedition EL tow vehicle, I wouldn't worry about the wheelbase or the trailer weight. I'd worry only about hitch weight.
The GVWR of the Expedition EL is your limiter. If you don't exceed the GVWR of the tow vehicle, then you won't exceed any other weight limit.
For example I'll use the 2009 model SUV. The big 2009 SUV with the HD trailer tow pkg and 3.73 axle ratio can tow a 8,700 pound trailer without being overloaded, but only if there is absolutely nothing in the SUV except a skinny driver. They have plenty of tow rating, but inadequate payload for much hitch weight.
Load the SUV with all the people, pets, tools, etc that will be in it when towing. Go to a truckstop that has a CAT scale. Fill up with gas and then weigh the wet and loaded SUV. Subtract the weight of the wet and loaded SUV from the GVWR. (The GVWR is on the driver's door or door frame.) The answer is the max hitch weight you can have without being overloaded.
Divide that max hitch weight by 0.12 and the answer is the max weight of any properly-loaded TT RV you can tow without being overloaded. And trust me - that max trailer weight is going to be a whole lot less than 8,700 pounds. In fact, if you don't have the HD tow pkg, the "tow rating" on a 2009 Expedition EL is only 6,000 pounds, and the max trailer weight you can tow without being overloaded is probably south of 5,000 pounds.
The limit on hitch weight is going to determine your max trailer length, and it will probably be short enough that the wheelbase of the SUV is not a concern.
Please don't tow overloaded. And in the case of a big SUV, the GVWR is the limiter to determine if you are overloaded or not.
There's a Suburban three-quarter ton chassis with a huge towing rating, but the wheelbase is still 130".
That one would probably be able to handle more hitch weight than the Expedition, but it will still be limited by the hitch weight. So ignore the 9,400 or 9,600 pounds tow rating of the 2012 2500 and worry about the hitch weight vs. GVWR. I don't see the payload ratings or GVWR for the Suburban, but it's probably not much more than the Expedition EL.