Look at the GCWR ‘gross combined weight rating’ of any rv you buy.
AFAIK, Ford and GM chassis offer more payload than the Sprinter chassis. Not that Sprinter is not capable, just know your numbers.
Get real weights of vehicles , not posted weights from brochures etc. An empty Wrangler is not the same real weight of one with its options, larger tires, racks, kayak and anything else that we all cram inside. Same goes for the rv. We all add bedding, tools, bbq’s, dishes, pots n pans and clothes.
Loading my rv and toad for a trip adds about 1000 lbs of weight.
