This calculator site should be a "Sticky".
I used this site when choosing my 5th wheel trailer and it caused me to stop considering a lot of trailers.
When I arrived in my Long Bed Xtended Cab 2500HD Allison/Duramax all the dealers said "You can pull anything on our lot" WRONG!!!
You can tell when a trailer salesman is lying about tow capacity because their lips are moving
Sure todays half ton trucks will pull a lot of trailers but how good do they stop and how long will the transmission last?
I think my truck pulling my 8285WS will yield better than average 5th wheel mileage.