milodon:
Seems I have unintentionally opened up another can of worms, but a double drive still only makes sense, if you’re running heavy all the time, as in 50+ ton gross. As shown from the pic by the owner of the first truck. And I’m willing to bet they still dump the air from the 3rd axle once in a while, as a 6x4 is not omnipotent.
As I said anything running with more more than half the axle weight of a single drive multiplied by two drives means a net gain in traction on firm ground and obviously almost half the axle weight applied to soft deep snow etc.While it’s obvious that a system which allows weight transfer in the case of a lightly loaded 6 x 4 is about as good as it gets assuming firm ground. 