If as donn mentioned, you load up the rig, weigh it, if it is at gvw, then you have NO tow capacity! unless you want to tow a trailer with no hitch wt!
There is not a what is comfortable as far as what you are asking. There are a couple of "rule of thumbs" besides staying under gvwr for the truck and trailer......
IIRC max length is 110" wb for 20', then add/subtract a foot of length per 4" of wb.
I use a max trailer weight of 2x the grawr.
Then use the gcwr as a guide per say. Then again, I also had and have a truck where the gcwr is lower than its gvwr! I guess I can not load to gvwr?!?!?!?!?!
BEST max trailer by lbs, is weigh the truck ready to go with people etc. Take the remaining payload to gvwr, divide by expected hw%, and you have max trailer you can tow. So if you have 1000 lbs left over, you have a max 10K ball mount trailer with 10% HW, or 4000 lbs if you tote a 5w with 25% hw! If the tow rating is under these amount, that that is your max warranty tow rating available to you!
Marty
