Originally Posted by Grumppy
The fifth wheel dealer says not that much will be added to the king pin weight and that the truck is fine. But we are cautious on what we have been told. Everyone wants to make a sale.
The king pin weight absolutely will go up. Your main storage is at the front of the camper in that glorious-sized basement.
For non-you haulers, you can usually estimate what a loaded pin weight will be by taking the dry hitch weight and dividing it by the dry loaded weight. This will give you the hitch weight percentage. This is generally somewhere between 17% and 25%.
Then you estimate how much crap you'll load into the water - necessities like propane, batteries, clothes, kitchen stuff, and optionals like water (fresh, gray, and black). An easy number is to say 1,500 pounds.be conservative, you'll surprise yourself if you weigh the camper down the road. More if you'll go on longer treks. Add that number to the dry hitch weight to come up with a "wet"/loaded weight.
The last trick to all of this. That dry percentage that we calculated first. For example, say 19%... it usually increases by 1-3% (and in rare cases, 4-5%). This is again due to that glorious basement carrying a lot of weight.
Now, multiple that loaded weight by the adjusted pin weight percentage. This will give you a ballpark number of what your pin weight will be.
I have an online calculator that does this all for you:
Calculator to estimate pin weights from dry weights
The truck needs to carry this weight as well as you, the spouse, any kids/fur-kids, and anything else in/on the truck (fancy rolltop cover you added, fifth wheel hitch, firewood, extra fuel, ect).