EV_dub wrote:Dosen't make sense to me. If my van is designed to carry a total load of 3500kg, then why can't
I have a Train weight of 3500kg. ah well..
If you could get your car into the van then your van will be able to brake more effectively as there is more weight over the tyres. If the weight was on a free wheeling trailer instead then the brakes on the van would be less effective and more liable to skid the tyres as the wheels lock up. Also the unbraked trailer could easily push the rear of the van sideways if it was braking on a curved road.
The train weight is a different issue.
The van loaded to 3500kg will have sufficient tractive effort to climb a gradient (I forget what it is but it is steep) but if it was towing a trailer to a train weight of 3500kg there would be less weight over the driving wheels and so it would have reduced tractive effort and will not be able to climb the same gradient. It is based on the ability to restart once stopped.
This is why Land Rovers have a towing capacity of 4500kg and a gross train weight of 7500kg, they are able to restart on a steep gradient using low range gears and four wheel drive.
My car, on the other hand, has a trailer weight of only 1400kg and it struggles to start that on the wet camber of a road junction due to front drive only.
I experienced this today with a trailer weight of only 1000kg. In the sudden rain and slippery roads I was wheel spinning just to move off driving over the Pennines. Made for interesting driving trying not to have to stop facing up hill.