I have the "little blue plate". Most important point is a GVM upgrade has no affect on tow capacity. There is no way in Oz to increase the your vehicles tow capacity. That limit is set in stone by the manufacturer and the design rules dont allow that to be changed. GVM upgrades only raises the vehicles weight carrying capacity. The theory is an engineer examines the vehicles capacity taking into account all manner of inputs over the obvious on being vehicle's inherent strength. The testing process requires examination of all stress areas, testing of steering, and real world track testing for braking capacity and sway, and a whole bunch of other hoodoo voodoo things.
A similar ATM upgrade process applies in a much simpler form with cavarans. Jayco uses the same chassis materials across all models from 1500kg to 3500kg ATM's just in different lengths etc. They then add ALKO components which come rated out of the box. The chassis have an engineered (well I hope they do) capacity way over what they will ultimately carry. Then Jayco weigh your individual van model and then add their standard payload. When Jayco change models within a range they have no clue what it will weigh before the first one comes off the production line.
Its no coincidence even though your vans ATM changes as you add a vast array of factory accessories, the physical make up of the chassis doesn't because in every instance the chassis components are know to be able to carry more; the van is simple under-rated to suit the standard Jayco kerb weight plus payload formula. Like my car, the van is quite capable of carry more than the original "little white plate" says; its simply under-rated below its real capacity by manufacturer at the factory.
Another similar "under rating" process car manufactures sometimes do is engine output capacity. My last work ute had a kW output of 126kW. A few model updates latter the exact same engine produced 146kW. There's persistent urban myth that the later model Toyota Prados are capable of towing 3500kg, but are under rated to protect the lucrative Landcruiser market
I have a 2104 Navara (best car ever, by the way) and it has a tow capacity of 3000kg, yet a Pathfinder with very similar componentry and coiled rear end has a tow capacity of 3500kg. Its also no coincidence that every single car has a round figure tow capacity ie 3500kg 3000kg 2500kg etc.
Vehicles GVM upgrades come with suspension upgrades for 2 important reasons. The first is the soft factory suspension used to soften the ride in order to sell the car is maybe not upto the task; but more importantly whilst GVM upgrades appear to be an "off the shelf" suspension company product, GVM upgrade are always provided by suspension suppliers because its a service to sell more suspension. The suspension companys such as Pedders have gone through the GVM re-engineering process only with popular vehicles in order to sell their suspension components. Thats why if you dont have a popular vehicle you simple cant get a GVM upgrade, because no-one supplies it. Dont confuse suspension upgrade with GVM upgrade
There's a little furphy floating about you can get any vehicle's GVM upgraded, and whilst that's true in theory finding a automotive engineer that will do it is the first hurdle, and the $15000 I was quoted is the second hurdle.
Therse also some furphys floating about how GVM upgrades are only legal in the state they are done. Whilst the the upgrade may well be only recorded with the registration authority of that state, its far from illegal, otherwise the ridiculous situation would arise where i would cease to have registration, or insurance as soon as I crossed a state border.
Last edited:
