[russellw]

The current Ranger dual cab makes an interesting case in point. (Please note: all figures are for the manual version).

It has a rated GCM of 6000 Kg. That's the total weight of the trailer/van unhitched, and the total weight of the vehicle unhitched, added together.

It has a rated GVM of 3200 Kg. That's the maximum allowed weight of the vehicle with everything in/on it, inclusive of the tow ball weight. Given that the kerb weight is nominally 2124Kg (with no accessories but including a full tank of fuel), that leaves a maximum theoretical payload of 1076 Kg. Note that the Auto adds 17 kg to the kerb weight and thus reduces the payload by that amount.

It also has a maximum front axle loading of 1480 Kg and 1850 Kg for the rear axle. The kerb weight is stated as 1159 kg for the front axle (manual) and 965 Kg for the rear axle. Add 17 Kg to the front axle for the auto. That allows (manual) 321 Kg of payload for the front axle and 885 Kg for the rear - except that would actually put it over the 3200 Kg GVM so in practice those loadings between them have to drop by 130 Kg.

It's probably not entirely accurate to say that the people add loading to the front axle as the design of the dual cab utes probably spreads at least some of it over the rear but it's fair to say that there isn't a lot of wriggle room with a 3T van.