228Driving and operatingThe driver assistance systems donot relieve the driver from full
responsibility for vehicle
operation.
Lane keep assist
Lane keep assist helps to avoid
crashes due to unintentional lane
departures. The front camera
observes the lane markings between
which the vehicle is driving. If the
vehicle approaches a lane marking,
the steering wheel is gently turned to
position the vehicle back into the lane. Turn steering wheel in same
direction, if system steering is not
sufficient. Turn steering wheel gently
into opposite direction, if lane change is intended.
When crossing a lane marking
significantly, lane keep assist starts a
visual and acoustic warning.
Unintended lane departure is
assumed
● without using turn signal
● using the turn signal in the opposite direction of the lane
departure
● without braking
● without acceleration
● without active steering.
Notice
The system is switched off during
detection of ambiguous lane
markings, e.g. in construction areas.
Notice
The system may be switched off if it
detects lanes which are too narrow,
too wide or too curved.
ActivationThe lane keep assist is activated by
pressing a. The LED in the button
illuminates to indicate that the system
is switched on.
When the control indicator a in the
instrument cluster or in the head-up display illuminates green, the system
is ready to assist.
The system is operational at vehicle
speeds between 37 mph and
112 mph and if lane markings are
available.
The system gently turns the steering
wheel and the control indicator a
changes to yellow, if the vehicle
approaches a detected lane marking
without using the turn signal in that
direction.
The system alerts by flashing a
together with three chimes, from the
respective direction, if the lane is
departed significantly.
Driving and operating229The system is only operable when a
lane marking is detected.
If the system only detects lane
markings on one side of the road, it
will only assist for this side.
Lane keep assist detects hands-free
driving. In this case a message in the
Driver Information Centre pops-up
and a chime sounds as long as lane
keep assist detects hands-free
driving.
Deactivation The system is deactivated by
pressing a; the LED in the button
extinguishes.
The system is deactivated
automatically when a trailer is
detected.
System limitations The system performance may not
operate properly when:
● Vehicle speed is out of range from 37 to 112 mph.
● Driving on winding or hilly roads.
● During nighttime driving.● Weather limits visibility, such as fog, rain, or snow.
● The sensor in the windscreen is blocked by snow, ice, slush, mud,dirt, windscreen damage or
affected by foreign items, e.g.
stickers.
● The sun is shining directly into the camera lens.
● Close vehicles ahead
● Banked roads
● Road edges
● Roads with poor lane markings ● Sudden lighting changes
● Vehicle modifications, e.g. tyres.
Switch off the system if the system is
disturbed by tar marks, shadows,
road cracks, temporary or
construction lane markings, or other
road imperfections.9 Warning
Always keep your attention on the
road and maintain proper vehicle
position within the lane, otherwise
vehicle damage, injury or death
could occur.
Lane keep assist does not
continuously steer the vehicle.
The system may not keep the
vehicle in the lane or give an alert,
even if a lane marking is detected.
The steering of the lane keep
assist may not be sufficient to
avoid a lane departure.
The system may not detect hands-
off driving due to external
influences (road condition and
surface, weather etc). The driver
has full responsibility to control the vehicle and is always required tokeep the hands on the steeringwheel while driving.
Using the system while towing a
trailer or on slippery roads could
cause loss of control of the vehicle
and a crash. Switch the system off.
230Driving and operatingFuel
Fuel for petrol engines Only use unleaded fuel that complies
with European standard EN 228 or equivalent.
The engine is capable of running with fuel that contains up to 10% ethanol
(e.g. named E10).
Use fuel with the recommended
octane rating. A lower octane rating
can reduce engine power and torque
and slightly increases fuel
consumption.Caution
Do not use fuel or fuel additives
that contain metallic compounds
such as manganese-based
additives. This may cause engine
damage.
Caution
Use of fuel that does not comply to EN 228 or equivalent can lead to
deposits or engine damage.
Caution
Use of fuel with a lower octane
rating than the lowest possible
rating could lead to uncontrolled combustion and engine damage.
The engine specific requirements
regarding octane rating are given in
the engine data overview 3 291. A
country-specific label at the fuel filler
flap can supersede the requirement.
Fuel additives outside Europe
Fuel should contain detergent
additives that help prevent engine
and fuel system deposits from
forming. Clean fuel injectors and
intake valves will allow the emission
control system to work properly.
Some fuel does not contain sufficient
quantities of additive to keep fuel
injectors and intake valves clean.
To make up for this lack of
detergency, add Fuel System
Treatment PLUS to the fuel tank at
every engine oil change or every
10,000 miles, whichever occurs first. It is available at your workshop.
Fuels containing oxygenates such as
ethers and ethanol, as well as
reformulated fuel, are available in
some cities. If these fuels comply with the previously described
specification, then they are
acceptable to use. However, E85
(85% ethanol) and other fuels
containing more than 15% ethanol
must be used only in FlexFuel
vehicles.Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
This damage would not be
covered by the vehicle warranty.
Driving and operating231Some fuels, mainly high octane
racing fuels, can contain an octane
enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use fuels or
fuel additives with MMT as they can
reduce spark plug life and affect
emission control system
performance. The malfunction
indicator light Z may turn on 3 107.
If this occurs, seek the assistance of
a workshop.
Fuel for diesel enginesOnly use diesel fuel that complies
with EN 590 and which has a sulphur
concentration of max. 10 ppm.
Fuels with a biodiesel (compliant with
EN 14214) content of max. 7% by
volume may be used (e.g. named
B7).
If travelling in countries outside the
European Union occasional use of Euro-Diesel fuel with a sulphur
concentration below 50 ppm is
possible.Caution
Frequent usage of diesel fuel containing more than 15 ppm
sulphur will cause severe engine
damage.
Caution
Use of fuel that does not comply to EN 590 or similar can lead to
engine powerloss, increased wear
or engine damage and may affect
your warranty.
Do not use marine diesel oils, heating
oils, Aquazole and similar diesel-
water emulsions. Diesel fuels must
not be diluted with fuels for petrol
engines.
Low temperature operation At temperatures below 0° C, some
diesel products with biodiesel blends may clog, freeze or gel, which mayaffect the fuel supply system. Starting
and engine operation may not work
properly. Make sure to fill winter
grade diesel fuel at ambient
temperatures below 0°C.
Arctic grade diesel fuel can be used
in extreme cold temperatures below
-20° C. Using this fuel grade in warm
or hot climates is not recommended
and may cause engine stalling, poor starting or damage on the fuel
injection system.
Refuelling
232Driving and operating9Danger
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.
Caution
In case of misfuelling, do not
switch on ignition.
Fuel filler flap is located at right rear
side of vehicle.
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
Place the nozzle in straight position to the filler neck and press with slight
force to insert.
To refuel, fully insert the pump nozzle
and switch it on.
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.
Close the flap and allow it to engage.
Misfuel inhibitor
9 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.
All vehicles are equipped with a
misfuel inhibitor.
Driving and operating233
The misfuel inhibitor ensures that theflap 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 is stowed 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 fuel into the
filler neck.
After topping-up, stow the funnel in
the load compartment.
Trailer hitch
General information
The factory-fitted towing equipment is
folded up under the rear bumper
fascia.
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. Only use
towing equipment that has been
approved for your vehicle.
To avoid vehicle damage, the power
tailgate cannot be operated with the
electronic key when a trailer is
electrically connected.
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.
234Driving and operatingDriving characteristics andtowing tips
Before attaching a trailer, lubricate the 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 50 mph. A maximum speed
of 60 mph is only appropriate if an
oscillation damper is used and the
permissible gross trailer weight does
not exceed the vehicle's kerb 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 3 300.Trailer towing
Trailer 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 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).The permissible gross train weight
must not be exceeded. This weight is specified on the identification plate
3 286.
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 of 60 kg
(engines B20DTH / B20NFT: 90 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.
Driving and operating235Rear axle loadWhen 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
70 kg (engines B20DTH: 80 kg), the
gross vehicle weight rating must not
be exceeded. If the permissible rear
axle load is exceeded, a maximum
speed of 60 mph applies.
Towing equipmentCaution
The folding coupling ball bar
cannot be removed from the
vehicle. When driving without a
trailer, fold in the coupling ball bar.
9 Warning
Make sure that no one is in the
pivot zone of the coupling ball bar. Risk of body injury.
When releasing the stowed
coupling ball bar, make sure to
stand left of the grip.
Release stowed coupling ball bar
Pull the grip located left to the number
plate under the rear bumper fascia at an angle of approx. 45° to the ground.
A buzzing tone sounds as a warning
when the release handle is pulled out and the ball neck is disengaged.
Take the released coupling ball bar
and raise it up until it engages.
Ensure the coupling ball bar is
correctly engaged and the released
handle is guided back to its hidden
initial position, otherwise the buzzing tone will not stop.