I thought I was on top of things doing all the weight calculations and bought a truck and 5th wheel. I pick it up next weekend. I came to realize that I messed up as I only included the dry hitch weig...
I experimented with the issue a couple years ago. I was over payload on a F350 SRW. My water tank is at the rear. I filled the water tank with 63 gallons and CAT scaled it. Then pulled into a corner of the truck stop, drained the water tank, and re scaled it. I think the full water tank took about 100 pounds off the pin. So, around a 1 to 4 ratio for me. Wasn't enough reduction for me.