Page 225 of 319

Driving and operating223and may cause engine stalling, poorstarting or damage on the fuel
injection system.
Fuel for natural gas operation
Natural gas is known as CNG
(Compressed Natural Gas).
Use natural gas with a methane
content of approx. 78 - 99%. L-gas
(low) has approx. 78 - 87% and H-gas (high) has approx. 87 - 99%. Biogas
with the same methane content can
also be used if it has been chemically
prepared and desulphurised.
Only use natural gas or biogas that complies with DIN 51624.
Liquid gas or LPG must not be used.
Refuelling9 Danger
Before refuelling, switch off
ignition and any external heaters
with combustion chambers.
Follow the operating and safety
instructions of the filling station
when refuelling.
9 Danger
Fuel is flammable and explosive.
No smoking. No naked flames or
sparks.
If you can smell fuel in your
vehicle, have the cause of this
remedied immediately by a
workshop.
A label with symbols at the fuel filler
flap is indicating the allowed fuel
types. In Europe the pump nozzles of the filling stations are marked with
these symbols. Refuel only the
allowed fuel type.
Caution
In case of misfuelling, do not
switch on ignition.
Fuel filler flap is located at right rear
side of the vehicle.
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224Driving and operating
The fuel filler flap can only be opened
if the vehicle is unlocked. Release the
fuel filler flap by pushing the flap.
Petrol and Diesel refuelling To open, turn the cap slowly
anticlockwise.The fuel filler cap can be retained in
the bracket on the fuel filler flap.
To refuel, switch on pump nozzle.
After the automatic cut-off, the tank can be topped up by operating the
pump nozzle a maximum of two more
times.
Caution
Wipe off any overflowing fuel
immediately.
To close, turn the fuel filler cap
clockwise until it clicks.
Close the flap and engage.
Misfuel inhibitor9 Warning
Do not try to open the flap of the
fuel filler neck manually on
vehicles with misfuel inhibitor.
Disregarding this could lead to
trapping of the fingers.
The misfuel inhibitor ensures that the flap of the fuel filler neck can only be
opened by using the suitable fuel
nozzle or a funnel for emergency
refilling.
In case of an emergency, refill with a
canister. A funnel must be used to
open the cap of the filler neck.
The funnel may be stowed in the load
compartment or the glovebox.
Place the funnel in straight position to the filler neck and press with slight
force to insert.
After topping-up, clean funnel from
fuel remains and stow it away.
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Driving and operating225Natural gas refuelling
The 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, gas composition and
type of refuelling system. Capacities
3 297.
Close the flap and allow it to engage. Terms for "natural gas vehicles"
abroad:GermanErdgasfahrzeugeEnglishNGVs = Natural Gas Vehi‐
clesFrenchVéhicules au gaz naturel -
or - Véhicules GNVItalianMetano auto
Terms for "natural gas" abroad:
GermanErdgasEnglishCNG = Compressed
Natural GasFrenchGNV = Gaz Naturel (pour)
Véhicules - or -
CGN = carburantgaz
naturelItalianMetano (per auto)Fuel filler cap
Only use genuine fuel filler caps. Diesel-engined vehicles have special fuel filler caps.
Page 228 of 319

226Driving and operatingTrailer hitch
General information
Only use towing equipment that has
been approved for your vehicle.
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 four
times five watt bulbs, the function only detects lamp outage when only a
single five 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 when
not in use.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.
During trailer towing do not exceed a
speed of 80 km/h. A maximum speed
of 100 km/h is only appropriate if an
oscillation damper is used and the
permissible gross trailer weight does
not exceed the vehicle’s curb weight.
For trailers with low driving stability
and caravan trailers, the use of an
oscillation damper is strongly
recommended.
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 3 298.Trailer towing
Trailer loadsThe 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 12%.
The permissible trailer load applies
up to the specified incline and at 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 altitude. The gross train weight does not have to be
reduced when driving on roads with
slight inclines (less than 8%, e.g.
motorways).
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Driving and operating227The permissible gross train weight
must not be exceeded. This weight is
specified on the identification plate
3 284.
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
40 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.
Stowage of coupling ball bar
The bag with the coupling ball bar is
stowed on the rear floor cover in the
load compartment.
Place the strap through the rear right
lashing eye, wrap around twice and
tighten the strap to secure the bag.
Illustration shows 5-door hatchback.
Illustration shows Sports Tourer.
Fitting the coupling ball bar
On Sports Tourer remove cover from
rear bumper by pushing.
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228Driving and operating
Disengage and fold down the
connecting 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 be approx. 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.
● Pull out rotary knob and turn
clockwise as far as it will go.
Inserting the coupling ball bar
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Driving and operating229Insert 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
Illustration shows 5-door hatchback.
Illustration shows Sports Tourer.
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.
● The coupling ball bar must be firmly engaged in the opening.
● The coupling ball bar must be locked and the key removed.9Warning
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
Page 232 of 319
230Driving and operatingOpen 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 connecting socket.
On Sports Tourer insert cover into
rear bumper as shown in the
illustration.
Stow the coupling ball bar in the bag
and secure by fixing the strap through the rear right lashing eye. Wrap
around twice and tighten the strap to
secure the bag.
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 is a function of
the Electronic Stability Control 3 183.