Lutz said:
Longhaul said:
The kerb weight of my vehicle is 1585kg (this is the same as the unladen weight. Not sure if there is a connection between the two)
By law, kerbweight and unladen weight are not one and the same. Kerbweight is with a full fuel tank and all other necessary fluids such as engine coolant and oils. Unladen weight is a dry weight.
otherclive said:
Kerbweight includes 75kg for a driver does your unladen weight include this.
Kerbweight does not include 75kg for the driver. Mass in Service, as quoted in the V5c, or Mass in Running Order, as it is more correctly called, does.
It all depends on what definition you use for kerb weight, which I agree can be confusing. Even the mags often say add the weight of fuel and driver to an unladen car. But I agree that if one was to use the unladen and unfilled weight of the car as kerb weight, then apply the 85% guide the results would err on the good side. But I do feel that would be unduly restrictive on choice, and not necessarily add to the safety of the outfit.
Lutz reference:
If you want a really accurate figure for kerbweight there's no alternative but to take the car to a weighbridge. Kerbweight is not something that is documented anywhere. What manufacturers call kerbweight in their publications is often not kerbweight according to the legal definition but mass in service and the difference between the two can, in the extreme, be as much as 150kg.
On the other hand, as Ern says, there's really no need to be so precise. Whether the weight ratio figure turns out to be 83% or 87% is not going to affect the handling and stability of the outfit to any noticeable extent. It's really only when you go over 100% that things can start to get a bit dodgy, and even then only under adverse conditions.
Edited August 8, 2017 by Lutz