The manual is designed for use by both intelligent people and idiots. Only you get to decide which rule system to use.
If you are an idiot, use the tow rating by number of passengers system. But even there, that tow rating is for a LOW profile trailer like a small boat or a popup camper, not a walk-in cargo trailer.
The other system requires both math and critical thinking skills. Most people CAN do this, but are too lazy. Thus the idiot system. I don't have the manual in front of my anymore, but it essentially comes down to a rating in which the empty van + 300# of people and stuff can pull a 3,500# trailer. Probably (more on that later). If people and stuff are more than 300#, you have to start deducting the excess directly from the tow rating. My 03 had a GCVWR (total allowed weigh of van, people, stuff and trailer) of 8,265#. Empty van with tow gear weighed about 4,465#.
So you have to check that ALL of the following are within specs:
1. Trailer weight is below max tow rating of 3,500#
2. Front axle is below GAWR.
3. Rear axle is below GAWR with trailer attached. A Weight distributing hitch can fix this if you go a bit over.
4. Van with trailer tongue attached and people and stuff inside is still below GVWR. Believe it or not, you can pass 2 and 3 above and flunk this one.
5. Total combined rig must weigh under GCVWR.
Now you know why they include the idiot chart in the manual!
