akrv wrote:
If the motorhome is your on a E450 your 12000 is kilograms not pounds the motorhome is built in Canada. That would mean the hitch would be 5442 lbs and a hitch weight of 544lbs. The numbers fall in line with my E450. Your biggest problem would be overloading the rear tires. I had a two horse side by side with two quarter horses and weight 4500lbs at the scale. I would run with all tanks empty and never more than 3/4 of a tank of gas. And was 300lbs under GAWR. Good luck
I think you converted kilograms to pounds the wrong way around; a kilogram is about 2.2 pounds, so 12,000 kg is around 26,400 pounds, and up in semi truck territory.
Just because a hitch is a class IV and rated for 10,000 pounds (or whatever class it may be) doesn't mean the vehicle can tow that much.
I can get a class III hitch (or, at least, a hitch with a 2" receiver) for my Honda Fit, but that doesn't mean it could tow anywhere near a 5000 pound trailer or support anything like a 500 pound tongue weight. Honda claims it can't tow anything; in practical terms, a utility trailer of maybe 1000 to 1500 pounds or so would work out acceptably well with reasonable care. The advantage of the class III hitch over a class I or II hitch in this case is the ability to attach things like sturdier bike racks.
For towing a big trailer behind a motorhome, a super C / "toterhome" is probably the best option.