My response was in relation to McG's words. Thanks for the information.
The Mack Truck program is called "Medium Support Vehicle System Project" as per the Canadian Governments specs. 7-10,000kg rating off road.
The Heavy Support vehicle is from 10,000+ kg ratings usually upwards of 16/17000kgs for the military.
With no firm definition of this because it depends on the configuration of the vehicle. Heavy Haul, Heavy transport, heavy lift etc.
Don't worry I have driven trucks up to and just over 200,000lbs /100tons (heaviest was 209,000lbs). I have driven these across farm fields and down some pretty tricky mud dirt roads. Chained up and given it across the fields and roads.
By the way it is pretty awesome that a Company DE Havilland Canada can build a limited market, limited number product for an affordable cost. When there is a will there is a way.