To the OP, regarding "payload" ( which is defined as GVWR minus curb weight ), I recently saw a good post on another forum, penned by a mechanical engineer. I saved it, since it was one of the best thought out and logical explanations I've seen:
"As an ME/PE and working 20 years in designing and operating equipment I am not sure you understand what drives payload and GVWR.
The same rigs get different ratings in different countries.
Safety procedures and GVWR are not directly related. Wear your seatbelts, follow your tires ratings. Don't exceed your hitch or axle ratings.
There was no SAE rating until very recently on towing. Payload/GVWR is still about aligning with tax/DOT laws. No relation to engineering. "
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Now then, also consider this: there are folks on this forum that will tell you "payload number" on a 2500 series truck may not even be adequate for your intended towing and load application. This is based on the fact that most 2500 series trucks have a 10000 pound GVWR.
Ok, so consider the following, which I pulled from a government website. We all know the gvmnt....that would be those pesky bureaucrats that write the regulations, etc:
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"Vehicle Regulations
If a vehicle has a GVWR of over 10,001 pounds and is used for a business, which includes non-profit businesses, then they are subject to federal and state safety regulations. Even though a driver does not need a commercial driving license for Class 1 through 6 vehicles, every vehicle that has a GVWR over 10,001 pounds has to be identified with the name of the company and the US DOT Number.
The driver has to operate under the regulations concerning hours of service and medical examinations are required for drivers. Any vehicle over 10,001 pounds is required to stop at state weigh and inspection stations.
Summary
Truck classification is determined by the gross vehicle weight rating (GVWR) and this determines the regulations that should be followed. A vehicle over 10,001 pounds means that the company and driver are required to follow regulations for the safe operation of commercial motor vehicles on US highways."
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My point is, dear original poster, as is usually the case, there is more to the story than what some internet experts might type into a forum post. I say it again, to really understand subjects such as payload, GVWR, axle ratings, one might need to do some digging and reading.
Many posters simply like to say, "you need a bigger truck". That's real easy for them to say, and type, but it may not tell the whole story.
I sure wish you, OP, were here at the resort I am staying at right now. If you were, we'd go for a walkabout here and talk to a dozen or so 1/2 ton truck owners that pulled their lengthy/heavy travel trailers here from far away places. You could in fact get info, straight from the horses mouth. Real world out here is a very interesting place.
But then as scout leaders, I know I don't need to tell you to really do your homework. You already know to do that.
EDIT: there are some folks whose default answer is "you need a bigger truck, or a smaller trailer".
It's the easy way out and does not require any reading or understanding of how all things work.
Expect someone to come along in this discussion and say : "one ton dually".
( not that I have anything against one ton duallies..... I have one )
