donn0128 wrote:
2500 should have a 10,000 GVWR. So, load it up and go to the scales. Simple subtraction will give you more info.
To expand on what Don is saying, here, "towing weight" is not the issue with fifth wheels and 3/4-ton diesel trucks. What you need to find out is how much payload you have left over after the truck is fueled, loaded, and has a hitch in the bed. The important number is the actual rear axle weight from the scales minus the RAWR (rear axle weight rating) from the door sticker. Multiply that number by 4 and you'll have an approximation of the gross/loaded weight of a fifth wheel you can tow. If you search the forum, you will find somewhere between dozens and hundreds of threads on this topic.
Rob