Yet another what can I tow question

bigcolasc wrote:
But isn't GWR subjective based on how much a person loads down the trailer?
Not really. It’s the max the trailer should weigh and not weigh more.

Doesn't it represent the maximum the trailer can be loaded down to?

Yes.
Worst case scenario: You load the trailer to its max, then take 13% of that for an optimal tongue weight. Theoretically, that will be the highest tongue weight you will have, though you can go to 15%.
That tongue weight figure will come off your payload.
Say you are looking at a camper that maxes out at 7000#.
13% of 7000 is 910.
That would be the max optimal tongue weight.
Say your truck has a payload of 1800#.
1800 - 910= 890
That leaves you with 890 for passengers, their stuff, whatever else is in the bed, and the weight of the weight distribution hitch (most figure about 100#).
Using the GWR gives you a max figure for your truck’s payload. To me, this is the easiest method to get an idea of what campers you can pull safely with your truck.