Vw Tiguan kerb weight

mrp62

According to the clubs web site the kerb weight is 1604 kg. The v5 show kerb weight as 1604 and the mass weight as 1679 . Took the car to a public weigh bridge with half a tank of fuel. I had it weighed with me in the vehicle and half the stuff we take camping.
That came to 1900 kg . Taking 100 kg off for me and 75 kgs for the equipment that leave 1725 kg considerably more than the quoted caravan club weight for a 2009 vw Tiguan tdi se auto . So why is such a low weight quoted ?