Vauxhall VECTRA Owner's Manual page 230

Coupling s ocket load
The c oupling socket load is the load
exerted by the carav an/trailer on the
coupling b all. It can be va ried by changing
the w eight distribution when loa ding the
carava n/trailer.
The ma ximum permissible coup ling socket
load (78 kg) for the towing v ehicle is
indicated on the towing equipment
identification plate and in the v ehicle
documents. Alway s aim for the m aximum
load, particularly in the ca se of heavy
carava ns/trailers. The coupling socket load
should never fall below 25 kg.
When mea suring the coup ling socket load,
mak e sure that the drawbar of the loa ded
carava n/trailer is at the sa me height as it
will be when the caravan/trailer is coupled
with the towing vehicle load ed. Particularly
important for caravans/trailers w ith
tandem axle.
228
Re ar axle load during towing
The permissible axle loads must not be
exc eeded.
Tyre inflation pressure
Increase the ty re p ressures on the towing
vehicle to the va lue specified for full load –
see page 290. Also chec k the p ressures of
the spare wheel and the carava n/trailer
tyres.