CITROEN DS3 Handbook page 236

Towing a trailer
Your vehicle is primarily designed for
transporting people and luggage, but it may
also be used for towing a trailer.
We recommend the use of genuine
CITROËN towbars and their harnesses
that have been tested and approved
from the design stage of your vehicle,
and that the fitting of the towbar is
entrusted to a CITROËN dealer or a
qualified workshop.
If the towbar is not fitted by a
CITROËN dealer, it must still be
fitted in accordance with the vehicle
manufacturer's instructions.
Driving with a trailer places greater
demands on the towing vehicle and the
driver must take particular care.
driving advice
distribution of loads
F Distribute the load in the trailer so that the
heaviest items are as close as possible to
the axle and the nose weight approaches
the maximum permitted without
exceeding it.
Air density decreases with altitude, thus
reducing engine performance. Above
1 000 metres, the maximum towed load must
be reduced by 10 % for every 1 000 metres of
altitude.
Refer to the "Technical data" section for
details of the weights and towed loads
which apply to your vehicle.