Operation
(2.5 miles), when fuel consumption will re-
t urn t
o a normal level.
Check tyre pressure
Always make sure the tyres are inflated to the
correct pressures ››› page 292 to save fuel. If
the pressure is below half bar, fuel consump-
tion may increase by 5%. Due to the greater
rolling resistance, under-inflation also increa-
ses tyre wear and impairs handling.
Do not use winter tyres all year round as they
increase fuel consumption by up to 10%.
Avoid carrying unnecessary loads
Given that every kilo of extra weight will in-
crease the fuel consumption, it is advisable
to always check the luggage compartment to
make sure that no unnecessary loads are be-
ing transported.
Since the luggage rack increases the aerody-
namic drag of the vehicle, you should remove
it when not needed. At speeds of 100-120
km/h (62-75 mph), this will save 12% of fuel.
Save electrical energy
The engine drives the alternator, thereby gen-
erating electricity. This implies that any in-
crease in power consumption also increases
fuel consumption! For this reason, switch off
any unneeded electrical devices. Devices that
use a lot of electricity includes the blower at a high setting, the rear window heating or
the seat
heating*.
Engine management and ex-
hau
st gas purification system
Introduction WARNING
● Bec
ause of the high temperatures which
can occur in the exhaust purification system
(catalytic converter or diesel particulate fil-
ter), do not park the vehicle where the ex-
haust can come into contact with flammable
materials under the car (e.g. on grass or at
the forest edge). Fire hazard!
● Do not apply wax underneath the vehicle
arou
nd the area of the exhaust system: Fire
hazard! Note
While the control lamps , , or re-
m
ain lit, there may be engine problems, fuel
consumption may increase and the engine
may lose power. Catalytic converter
3 Ap
plies to vehicles with petrol engine
The
vehicle must only be used with unleaded
petrol, otherwise the catalytic converter will
be irreparably damaged.
Never drive until the tank is empty; an irregu-
lar supply of fuel can cause faulty combus-
tion. In these cases, unburned fuel reaches
the exhaust system, which can overheat and
damage the catalytic converter.
Diesel particulate filter 3 Ap
p
lies to vehicles with diesel engine
The diesel engine particulate filter eliminates
most of the soot from the exhaust gas sys-
tem. Under normal driving conditions, the fil-
ter cleans itself. The diesel particulate filter is
cleaned automatically without need for indi-
cation by the warning lamp . This may be
noticed because the engine idle speed in-
creases and an odour may be detected.
If automatic filter purification cannot be car-
ried out (because only short trips are taken,
for example), soot will accumulate on the fil-
ter and the Diesel particulate filter warning
lamp will switch on.
Facilitate the automatic filter cleaning proc-
ess by driving in the following manner: drive
for approximately 15 minutes at a minimum
speed of 60 km/h (37 mph) in 4th or 5th gear
186
Intelligent technology
parked. It controls the supply of power to the
v ariou
s electrical devices while the ignition is
switched off. The system takes the battery di-
agnosis data into consideration.
Depending on the power level of the battery,
switch off the individual electrical devices
one after the other to prevent the battery
from losing too much charge and to ensure
that the engine can be started reliably.
Dynamic power management
While the vehicle is moving, this function dis-
tributes the available power to the various
electrical devices and systems according to
their requirements. The power management
ensures that on-board systems do not con-
sume more electrical power than the alterna-
tor can supply, and thus maintains the maxi-
mum possible battery power level. Note
● Neither i s
the power management system
able to overcome the given physical limits.
Please remember that the power and useful
life of the battery are limited.
● When there is a risk that the vehicle will
not s
tart, the alternator power failure or low
battery charge level warning lamp will be
shown ››› page 106. Flat battery
Starting ability has first priority.
Shor
t
trips, city traffic and low temperatures
all place a heavy load on the battery. In these
conditions a large amount of power is con-
sumed, but only a small amount is supplied.
The situation is also critical if electrical devi-
ces are in use when the engine is not run-
ning. In this case power is consumed when
none is being generated.
In these situations you will be aware that the
power management system is intervening to
control the distribution of electrical power.
When the vehicle is parked for long periods
If you do not drive your vehicle for a period of
several days or weeks, the power manage-
ment will gradually shut off the electrical de-
vices one by one or reduce the amount of cur-
rent they are using. This limits the amount of
power consumed and helps to ensure relia-
ble starting even after a long period. Some
convenience functions, such as remote vehi-
cle opening, may not be available under cer-
tain circumstances. These functions will be
restored when you switch on the ignition and
start the engine. With the engine switched off
F
or e
xample, if you listen to the sound sys-
tem with the engine switched off the battery
will run down.
If the energy consumption means there is a
risk that the engine will not start, a text will
appear in vehicles with a driver information
system*.
This driver indicator tells you that you must
start the engine so that the battery can re-
charge.
When the engine is running
Although the alternator generates electrical
power, the battery can still become dis-
charged while the vehicle is being driven.
This can occur when a lot of power is being
consumed but only a small amount supplied,
especially if the battery is not fully charged
initially.
To restore the necessary energy balance, the
system will then temporarily shut off the elec-
trical devices that are using a lot of power, or
reduce the current they are consuming. Heat-
ing systems in particular use a large amount
of electrical power. If you notice, for instance,
that the seat heating* or the rear window
heater is not working, they may have been
temporarily switched off or regulated to a
lower heat output. These systems will be
available again as soon as sufficient electri-
cal power is available. »
275
Technical data
Advice
Operation
Emergencies
Safety
Advice
You may also notice that the engine runs at a
s lightly
faster idling speed when necessary.
This is quite normal, and no cause for con-
cern. The increased idling speed allows the
alternator to meet the greater power require-
ment and charge the battery at the same
time. Checking and refilling levels
Fi l
ling the tank
Filling up Read the additional information carefully
› ›
› page 48
If the automatic filler nozzle is operated cor-
rectly, it will switch itself off as soon as the
fuel tank is “full”. Do not try to put in more
fuel after the nozzle cuts out, as this will fill
the expansion chamber in the fuel tank.
The correct fuel grade for your vehicle is giv-
en on a sticker on the inside of the fuel tank
flap. Further notes on fuel can be found at
››› page 277.
The capacity of your vehicle's fuel tank is giv-
en in ›››
page 48. WARNING
Fuel is highly flammable and can cause seri-
ou s
burns and other injuries.
● When refuelling, turn off the engine, the
auxi
liary heater ››› page 161 and turn off the
ignition for safety reasons.
● Do not smoke when filling the fuel tank or a
cani
ster. Naked flames are forbidden in the
vicinity due to the risk of explosion. ●
Ob
serve legislation governing the use,
storage and carrying of a spare fuel canister
in the vehicle.
● For safety reasons we do not recommend
carr
ying a spare fuel canister in the vehicle.
In an accident the canister could be damaged
and could leak.
● If, in exceptional circumstances, you have
to c
arry a spare fuel canister, please observe
the following points:
– Never fill fuel into the spare fuel canister
if it is inside or on top of the vehicle. An
electrostatic charge could build up during
filling, causing the fuel vapour to ignite.
Danger of explosion. Always place the
canister on the ground to fill it.
– Insert the filling nozzle as far as possible
into the spare fuel canister.
– If the spare fuel canister is made of met-
al, the filling nozzle must be in contact
with the canister during filling. This
helps prevent an electrostatic charge
building up.
– Never spill fuel in the vehicle or in the
luggage compartment. Fuel vapour is ex-
plosive. Risk of fatal accident! CAUTION
● If an
y fuel is spilt onto the vehicle, it
should be removed immediately. It could oth-
erwise damage the paintwork.
● Never run the tank completely dry. An irreg-
ul
ar fuel supply could cause misfiring. As a 276
Checking and refilling levels
WARNING
● Sw it
ch the engine off, remove the key from
the ignition and apply the hand brake. If the
vehicle has a manual gearbox, place the lever
in neutral; if it has an automatic gearbox,
place the selector lever in position P. Wait for
the engine to cool down.
● Keep children away from the engine com-
par
tment.
● Never spill liquids used for vehicle opera-
tion on the engine c
ompartment, as these
may catch fire (e.g. the antifreeze in coolant).
● Take care not to cause short circuits in the
electric
al system, especially when working
on the battery.
● If working inside the engine compartment,
remember th
at, even when the ignition is
switched off, the radiator fan may start up au-
tomatically, and therefore there is a risk of in-
jury.
● Never cover the engine with additional in-
su
lating materials such as a blanket. Risk of
fire!
● Do not unscrew the cap on the coolant ex-
pan
sion tank when the engine is hot. The
cooling system is under pressure.
● Protect face, hands and arms by covering
the cap w
ith a large, thick rag to protect
against escaping coolant and steam.
● If it is necessary to work in the engine com-
par
tment while the engine is running, the ro-
tating components (for example, poly-V belt, alternator, radiator fan) and the high voltage
ignition sy
s
tem are an additional hazard.
● Observe the following additional warnings
if w
ork on the fuel system or the electrical
system is necessary:
– Always disconnect the battery from the
on-board network.
– Do not smoke.
– Never work near naked flames.
– Always keep an approved fire extinguish-
er immediately available. CAUTION
When topping up fluids make sure the correct
fluid i s
put into the correct filler opening, oth-
erwise this can cause serious malfunctions or
engine damage. For the sake of the environment
Inspect the ground underneath your vehicle
r e
gularly so that any leaks are detected at an
early stage. If you find spots of oil or other
fluids in the area where it was parked, have
your vehicle inspected at the workshop. Note
In right-hand drive vehicles* some brake flu-
id r e
servoirs are on the other side of the en-
gine compartment ››› Fig. 221. Opening the bonnet
Read the additional information carefully
› ›
› page 11
The bonnet is released from inside the vehi-
cle.
Check that the windscreen wiper arms are
not unfolded. Otherwise the paint may be
damaged.
The bonnet can only be unlocked when the
driver door is open. WARNING
Never open the bonnet if you see steam or
drip s
of coolant being released from the en-
gine compartment. Failure to comply could
result in burns. Wait until no steam or coolant
can be seen before opening the bonnet. Closing the bonnet
–
Slightly lift the bonnet.
– Release the bonnet stay before pressing it
bac
k into its support.
– Carefully close the bonnet.
– Press the bonnet down until it locks into
pl
ace.
– Make sure that the bonnet catches onto its
cl
asp. Do not press down too hard ››› .
»
283
Technical data
Advice
Operation
Emergencies
Safety