RTA says 1.5 x the unladen mass of the towing vehicle where not specified (see link below). Unladen mass of a HZ XX7 van is easy, GVW is 2000kg, carrying capacity is 10cwt (508kg) (see http://en.wikipedia.org/wiki/Hundredweight). So Unladen mass is 1492kg, so 2238kg towing mass assuming the trailer is setup for that (over-ride brakes to 2000kg only).

What you have to watch for though is you can only carry 508kg. So do sums first:

On a 2000kg trailer towball weight will be about 200kg.
2 x say 75kg people = 150kg.
80L of petrol will weigh about 50kg.
Towbar will be about 25kg.

So that is 425kg, leaving you only with 75kg of luggage, or if you weigh 125kg like me then you've only got 25kg of luggage left, so the back of the van empty. You'll easily use up that 25kg in UHF radio, speakers, 12V fridge etc.

See why some people wanted XU3's?

http://www.rta.nsw.gov.au/registrati...ngtrailers.pdf