Actually, total payload INCLUDES the passengers. Now camper or bed load, is total payload less # of seatbelts time 154 lbs per!
My truck has a door sticker of 4100, camper load is 3200. My C2500, has a door sticker payload of 3800, camper load of 3350!
GCWR on the other hand, is not a legal term, and Weight cops on the road will nto ticket you for being over or under this amount. Also having been pulled over by a few of them, taken a class or 3 or 4 from them, the axel and gvwr sticker on the side of the door is also not a legal number one has to follow. Most only care what your paid for license/registration says. So my C2500 since I have an 8000 lbs plate, that is ALL I am good too! If I load up to the door sticker gvwr of 8600, get pulled over, I am overwt by 600 some lbs! My dully on theother hand, has a registration plate of 14K lbs, which is over the door sticker gvwr and the sum of the door sticker axel ratings. I am legal to 14K lbs. the door sticker at least in wa st, means squat!
At the end of the day, to me, you still need the proper payload to tow a trailer equal to what ever % HW you need, along with passengers etc. FOr some of us, we will need a Crew cab with 3000 lbs of payload, and will use ALL 3000 lbs of payload while towing a 6500 lbs trailer as I did with my family of 6 that totals 1200 or so lbs when my kids were adult sized teens! We would have typical crew cab 15 series truck at gvwr before loading a trailer. So for me any how. those trucks have ZERO, NADA, NO tow rating ability!
Marty