The one motorhome wiht a 2,500 pound capacity is probably off, and is actually something like this to calculate it correctly. Say the GVWR is 22,000 pounds and the GCVWR is 24,500, you might guess that it can only tow 2,500 pounds, however the correct tow rating is the curb weight ready togo camping, then take that away from the GCVWR, and you will have the amount that you can tow.
I hate it when someone states the GCVWR is say 26,000 and the GVWR is 22,000, so the tow limit is only 4,000 pounds, it is totally incorrect, becuase to tow a 4,000 pound trailer, the RV must have 400 pounds below it's GVWR to accept the hitch weight, therefore the RV will be at least 500 pounds below it's GVWR, and can tow at least 4,500 pounds. The actual number can be substantially more, for instance my RV has a 26,000 GCVWR from Ford, but only a 17,000 GVWR, and has a curb weight of around 16,000 pounds. So in therory, my RV could tow 10,000 pounds, and put 1,000 pounds of that onto the hitch. However Fleetwood extended the Ford factory frame by 13" in my case, so I can not mount the hitch on the Ford factory frame, but on the Fleetwood extensions. Fleetwood only rated the 97's gas engine chassis to tow about 3,500 pounds due to the long extensions on some of their chassis designs, such as the 38' with a tage axle and 178" chassis, and a 12 foot long frame extension behind the Ford frame, that the hitch is attached to.
So I would say that 5,000 is about all the Fleetwood extended frame is good for, unless you have a DP Fleetwood that is rated at a higher weight.
As for a good towing diesle pusher, look at Alpine. Not only did they usually come with a 400 HP engine, but also have a huck bolted on 10,000 pound hitch on all the DP's in their lineup!
Even if the hitch is rated at 10,000 pounds (most are) it does not mean the manufacture rated the RV to tow that much, and also that the cargo rating is over 1,000 pounds, so you can put that much hitch weight on the RV.
Check the GVWR and GVW of the RV you are looking at on a scale. If the rear axle is say 2,200 pounds under on it's GVW compared to the weight rating, then it would work, providing everything else seems to work for you. The 700 - 1,000 pounds of hitch weight will be about 10 or 12 feet behind the axle, and a almost equal weight will be taken off the front axle and applied to the back axle when you hitch up the trailer.
Lets figure it out exactly for a 12' hitch ball to center of rear axle, with a 240" wheelbase diesel pusher. 700 pounds down on the hitch will take off 350 pounds from the front tires, and apply 1,050 pounds to the rear axle. If the wheelbase is shorter, say 200", then more weight will come off the front axle, say 450 pounds, applying 1150 pounds to the rear axle.
In addition, when camping you normally will be putting in up to 100 gallons of fresh water that was not there when you checked the RV weight during a test drive. That is 800 pounds, probably distributed equally between the axles, but check the tank location to make sure. And you will normally add about 800 more pounds of camping gear too, including food, clothing, blankets, chairs, ect.
Fred.
