King Pin Weight

[Big White Dmax]

A 2500 HD Dmax is at least 7000 pounds bone stock with a driver and a full tank of fuel.
The GVWR is 9200 so that leaves a payload of 2200 pounds.
A 2500 pound pinweight will overload this truck by 300 pounds even before you add passengers, tools, and everything else you plan to bring with you.
My fiver has a 2600 pound pin weight and my new Dually has an 11400 pound GVWR.
My truck is 7600 pounds so I have a 3800 pound payload. (11400 minus 7600 = 3800)
I can carry another 1200 pounds along with my Fiver, so as long as I keep my three fattest Aunts out of the back seat, I should be OK.

[charlesha11]

The per axel gross is higher than the GVWR weight that does allow over 2500 lb on the rear axel

[Big White Dmax]

Axle ratings are always higher than Gross ratings and this is your safety factor.
When you are over your GVWR, you are overweight in the eyes of the law and people that
built the truck. Most SRW and some dually trucks pulling big fivers are overweight.
It is up to your own comfort level to decide if you want to run overweight. The world is changing and when lawyers and insurance companies get involved, it is a nice feeling to be within your truck specs. No other issue is so hotly debated on RV forums.
A large group of people have no idea that they are overweight, a large group know it and ignore it and a smaller group tries to comply. Good luck with your choice.

[dandy]

Open up the driver's door and the tag on the door post will show you exactly what the load capacity of your truck is. Now, That's total load as has been indicated on other posts. It includes all passengers, fuel, fifthwheel hitch, any other cargo in the truck, and then what's left is what you can use for your pin weight. Door post will probably show around 2500#.
Many 2500HD pickups are taking on much more than this, but they are all exceeding the truck's gross of 9200#.
I do, with my 32' fifth wheel. The dealer told me that I had more than enough truck when I bought it. Too late for me.
Like everyone else, I upgraded my rear tires, and I don't overload them, so I personnally feel ok with it.
If the info from the dealer had been correct, I would have bought a duelly.
If you haven't purchased a trailer yet, look for one with a lower pin weight. Good luck.