210Driving and operating
Fuel selector
Pressing button Y switches between
petrol and natural gas operation.
Switching is not possible at high loads
(e.g. strong acceleration, running at
full throttle). The LED status shows
the current operating mode.
1 off=natural gas
operation.1 illumi‐
nates=petrol operation.1 flashes=no switching is
possible, one type
of fuel is empty.As soon as the natural gas tank is
empty, petrol operation is
automatically engaged until the
ignition is switched off.
If the natural gas tank is not refuelled, the system must be manually
switched to petrol operation before
the engine is started-up again. This
will prevent damage to the catalytic
converter (overheating caused by
irregular fuel supply).
If the selector switch is operated
several times within a short time, a
switchover block is activated. The engine remains in the current
operating mode. The block remains
active until the ignition is switched off.
A slight loss of power and torque can be expected during petrol operation.
You must therefore adapt your driving
style (e.g. during overtaking
manoeuvres) and vehicle loads (e.g.
towing loads) accordingly.
Every six months run the petrol tank
down until control indicator Y
illuminates, then refuel. This isnecessary to maintain fuel quality as
well as system function necessary for
petrol operation.
Fill the tank completely at regular intervals to prevent corrosion in the
tank.
Fuel for liquid gas
operation Liquid gas is known as LPG
(Liquefied Petroleum Gas) or under its French name GPL (Gaz de Pétrole Liquéfié). LPG is also known as
Autogas.
LPG consists mainly of propane and
butane. The octane rating is between
105 and 115, depending on the
butane proportion. LPG is stored
liquid at around 5 - 10 bar pressure.
The boiling point depends on the
pressure and mixing ratio. At ambient pressure, it is between -42 °C (pure
propane) and -0.5 °C (pure butane).
214Driving and operating
The misfuel inhibitor ensures that theflap of the fuel filler neck can only be
opened by using a nozzle for diesel
fuel or a funnel for emergency
refilling.
Turn the fuel filler cap slowly anti-
clockwise.
The cap can be retained in the
bracket on the fuel filler flap.
Place the nozzle in straight position to
the filler neck and press with slight
force to insert.
In case of an emergency refilling with a canister, a funnel must be used to
open the cap of the filler neck.The funnel is located on the right side storage in the load compartment.
Place the funnel in straight position to
the filler neck and press with slight
force to insert.
Use the funnel to fill in the diesel fuel
into the filler neck.
After topping up, put the funnel into
the plastic bag and stow it in the
storage compartment.
Selective catalytic reduction system
3 166.
Natural gas refuellingThe fuel filler flap can only be opened
if the vehicle is unlocked. Release the
fuel filler flap by pushing the flap.9 Warning
Refuel only with a maximum
output pressure of 250 bar. Use
only temperature compensated
filling stations.
The refuelling procedure must be
completed, i.e. the filler neck must be
vented.
The capacity of the natural gas tank depends on outside temperature,
filling pressure and type of refuelling
system. Capacities 3 284.
Close the flap and allow it to engage. Terms for "natural gas vehicles"
abroad:
218Driving and operating
Natural gas
The fuel consumption information
was obtained using reference fuel
G20 (methane proportion
99 - 100 mol%) under prescribed
driving conditions. When using
natural gas with a lower proportion of
methane, the fuel consumption can
differ from the specified values.Trailer hitch
General information
Only use towing equipment that has
been approved for your vehicle.
Vehicles with natural gas engines
require special towing equipment.
Entrust retrofitting of towing
equipment to a workshop. It may be
necessary to make changes that
affect the cooling system, heat
shields or other equipment.
The bulb outage detection function for
trailer brake light cannot detect a
partial bulb outage. E.g. in case of
4x 5 Watt bulbs, the function only
detects lamp outage when only a
single 5 Watt lamp remains or none
remain.
Fitting of towing equipment could
cover the opening of the towing eye.
If this is the case use the coupling ball bar for towing. Always keep the
coupling ball bar in the vehicle.Driving characteristics and
towing tips Before attaching a trailer, lubricatethe coupling ball. However, do not do
so if a stabiliser, which acts on the coupling ball, is being used to reduce snaking movements.
For trailers with low driving stability
and caravan trailers with a permitted
gross vehicle weight of more than
1300 kg the use of a stabiliser is
strongly recommended when driving
above 80 km/h.
If the trailer starts snaking, drive more slowly, do not attempt to correct the
steering and brake sharply if
necessary.
When driving downhill, drive in the
same gear as if driving uphill and
drive at a similar speed.
Adjust tyre pressure to the value
specified for full load 3 285.
Driving and operating219Trailer towingTrailer loads
The permissible trailer loads are
vehicle and engine-dependent
maximum values which must not be
exceeded. The actual trailer load is
the difference between the actual
gross weight of the trailer and the
actual coupling socket load with the
trailer coupled.
The permissible trailer loads are
specified in the vehicle documents. In general, they are valid for gradients
up to max. 12 %.
The permitted trailer load applies up
to the specified incline and up to an
altitude of 1000 metres above sea
level. Since engine power decreases
as altitude increases due to the air
becoming thinner, therefore reducing
climbing ability, the permissible gross
train weight also decreases by 10 %
for every 1000 metres of additional
altitude. The gross train weight does
not have to be reduced when driving
on roads with slight inclines (less than
8 %, e.g. motorways).The permissible gross train weight
must not be exceeded. This weight is specified on the identification plate3 271.
Vertical coupling load
The vertical coupling load is the load
exerted by the trailer on the coupling
ball. It can be varied by changing the
weight distribution when loading the
trailer.
The maximum permissible vertical
coupling load (75 kg) is specified on
the towing equipment identification
plate and in the vehicle documents.
Always aim for the maximum load,
especially in the case of heavy
trailers. The vertical coupling load
should never fall below 25 kg.Rear axle load
When the trailer is coupled and the
towing vehicle fully loaded, the
permissible rear axle load (see
identification plate or vehicle
documents) may be exceeded by
60 kg , the gross vehicle weight rating
may be exceeded by 60 kg. If the
permissible rear axle load is
exceeded, a maximum speed of
100 km/h applies.
Towing equipmentCaution
When operating without a trailer,
remove the coupling ball bar.
220Driving and operating
Stowage of coupling ball bar
The bag with the coupling ball bar is
stowed in the load compartment.
Place the strap through the right rear lashing eye, wrap around twice and
tighten the strap to secure the bag.
Fitting the coupling ball bar
Disengage and fold down the socket. Remove the sealing plug from the
opening for the coupling ball bar and
stow it.
Checking the tensioning of the
coupling ball bar
■ Red marking on rotary knob must
point towards green marking on
coupling ball bar.
■ The gap between the rotary knob and the coupling ball bar must beapprox. 6 mm.
■ The key must be in position c.
Otherwise, the coupling ball bar must be tensioned before being inserted:
■ Unlock coupling ball bar by turning key to position c.
Driving and operating221
■ Pull out rotary knob and turnclockwise as far as it will go.
Inserting the coupling ball bar
Insert the tensioned coupling ball bar
in the opening and push firmly
upwards until it audibly engages.
The rotary handle snaps back into its
original position resting against the
coupling ball bar without a gap.9 Warning
Do not touch rotary handle during
insertion.
Lock the coupling ball bar by turning
the key to position e. Remove the key
and close the protective flap.
Eye for break-away stopping cable
Attach breakaway stopping cable to
eye.
Check that the coupling ball bar is correctly installed
■ Green marking on rotary knob must
point towards green marking on
coupling ball bar.
■ There must be no gap between the
rotary handle and the coupling ball
bar.
222Driving and operating
■The coupling ball bar must be firmly
engaged in the opening.
■ The coupling ball bar must be locked and the key removed.9 Warning
Towing a trailer is permitted only
when a coupling ball bar is fitted correctly. If the coupling ball bardoes not engage correctly, seekthe assistance of a workshop.
Dismounting the coupling ball
bar
Open the protective flap and turn the
key to position c to unlock the
coupling ball bar.
Pull out rotary handle and turn
clockwise as far as it will go. Pull out coupling ball bar downwards.
Insert sealing plug in opening. Fold away socket.
Trailer stability assist If the system detects snaking
movements, engine power is reduced
and the vehicle/trailer combination is
selectively braked until the snaking ceases. While system is working keep steering wheel as still as possible.
Trailer stability assist (TSA) is a
function of the Electronic Stability
Control 3 177.
Vehicle care253
3. Remove the electrical connectioncable and air hose from the
stowage compartments on the
underside of the compressor.
4. Screw the compressor air hose to
the connection on the sealant
bottle.
5. Fit the sealant bottle into the retainer on the compressor.
Set the compressor near the tyre
in such a way that the sealant
bottle is upright.
6. Unscrew valve cap from defective
tyre.
7. Screw the filler hose to the tyre valve.
8. The switch on the compressor must be set to J.
9. Connect the compressor plug to
the power outlet or cigarette
lighter socket.
To avoid discharging the battery,
we recommend running the
engine.
10. Set the rocker switch on the compressor to I. The tyre is filled
with sealant.
11. The compressor pressure gauge briefly indicates up to 6 bar whilstthe sealant bottle is emptying
(approx. 30 seconds). Then the
pressure starts to drop.