Hello , this may help you , on your VIN plate the first figure below the VIN number is the vehicles kerb side weight 2100Kg . The next figure down is your gross train weight 3900 , you deduct 2100 from 3900 & arrive at 1800 Kg .
You really need to use a weigh bridge to make sure you comply , it is very easy to exceed these limits and the Plod & VOSA do perform "roadside " weighing sessions .
Hope this helps
