How to Calculate Permissible Mass

Calculating permissible tractor mass and permissible trailer mass on the basis of the D value

EC-approved, dynamically tested hitches are always provided with a D value. This is calculated as follows:

D =	G * A * B A + B	, where
D =	D value of hitch
G =	Gravitational constant 9.81 m/s2
A =	Tractor mass
B =	Trailer mass

To calculate trailer mass for a given D value and a given tractor mass, and to calculate tractor mass for a given D value and a given trailer mass, use the following formulas:

Tractor mass	A =	D * B (G * B) - D
Trailer mass	B =	D * A (G * A) - D

Example of how to calculate permissible trailer mass:

Given that:	D value, D = 45.9 kN = 45900 N
	Tractor mass A = 6000 kg
B =	45900 N * 6000 kg (9.81 m/s2 * 6000 kg) - 45900 N	= 21250 kg

Pay close attention to permissible towed mass and tractor mass!