188Intelligent technology
Brakes
General notes
New brake pads
New brake pads do not provide optimal performance during the first 200
km; first they must be “run in”. However, the reduced braking capacity may
be compensated by pressing on the brake pedal a little harder. Avoid over-
loading the brakes during run-in.
Wear
The rate of wear on the brake pads depends a great deal on how you drive
and the conditions in which the vehicle is operated. Negative factors are, for
instance, city traffic, frequent short trips or hard driving with abrupt starts
and stops.
Wet roads or road salt
In certain conditions, such as in heavy rain, or after washing the vehicle or
driving through water, the full braking effect can be delayed by moisture (or
in winter by ice) on the discs and brake pads. In this case the brakes should
be dried by pressing the brake pedal several times.
When the speed is over 80 km/h and the windscreen wipers are on, the
brake system moves the pads towards the brake discs for a few seconds.
This occurs - without the driver knowing - at regular intervals and allows a
faster response from the brakes when driving on wet roads.
The effectiveness of the brakes can also be temporarily reduced if the vehi-
cle is driven for some distance without using the brakes when there is a lot
of salt on the road in winter. In this case, the layer of salt on the brake discs
and pads has to wear off before braking.
Corrosion
There may be a tendency for corrosion to form on the discs and dirt to build
up on the brake pads if the vehicle is used infrequently or the brakes are
not used very often. If the brakes are not used frequently, or if rust has formed on the disks, it is
advisable to clean off the pads and disks by braking firmly a few times at a
moderately high speed
⇒
.
Faults in the brake system
If the brake pedal travel should ever increase suddenly, this may mean that
one of the two brake circuits has failed. Drive immediately to the nearest
specialised workshop and have the fault repaired. Drive there slowly and re-
member that you will have to apply more pressure on the brake pedal and
allow for longer stopping distances.
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is too
low. The brake fluid level is monitored electronically.
WARNING
When applying the brakes to clean off deposits on the pads and discs,
select a clear, dry road. Be sure not to inconvenience or endanger other
road users. Risk of accident.
CAUTION
● Never let the brakes “drag” by leaving your foot on the pedal when it is
not necessary to brake. This overheats the brakes, resulting in longer stop-
ping distances and greater wear.
● Before driving down a long, steep gradient, it is advisable to reduce
speed and change to a lower gear (or move the gear lever to a lower gear
position if your vehicle has automatic transmission). This makes use of en-
gine braking and prolongs the service life of the brakes. If you still have to
use the brakes, it is better to brake firmly at intervals than to apply the
brakes continuously.
194Driving and the environment
Avoid idling
It is worthwhile switching off the engine when waiting in a traffic jam, at lev-
el crossings or at traffic lights with a long red phase. The fuel saved after
only 30 - 40 seconds is greater than the amount of fuel needed to restart
the engine.
The engine takes a long time to warm up when it is idling. Mechanical wear
and pollutant emissions are also especially high during this initial warm-up
phase. It is therefore best to drive off immediately after starting the engine.
Avoid running the engine at high speed.
Periodic maintenance
Periodic maintenance work guarantees that, before beginning a journey,
you will not consume more than the required amount of fuel. A well-serviced
engine gives you the benefit of improved fuel efficiency as well as maxi-
mum reliability and an enhanced resale value.
A badly serviced engine can consume up to 10% more fuel than necessary.
Avoid short journeys
To reduce the consumption and emission of polluting gases, the engine and
the exhaust filtration systems should reach the optimum service tempera-
ture.
With the engine cold, fuel consumption is proportionally higher. The engine
does not warm up and fuel consumption does not normalise until having
driven approximately four kilometres. This is why we recommend avoiding
short trips whenever possible.
Maintain the correct tyre pressures
Bear in mind that keeping the tyres at an adequate pressure saves fuel. If
the tyre pressure is just one bar too low, fuel consumption can increase by
as much as 5%. Due to the greater rolling resistance, under-inflation also
increases tyre wear and impairs handling.
The tyre pressures should always be checked when the tyres are cold.Do not use
winter tyres all year round as they increase fuel consumption by
up to 10%.
Avoid unnecessary weight
Every kilo of extra weight will put up the fuel consumption, so it is worth
checking the luggage compartment occasionally to make sure that no un-
necessary loads are being transported.
A roof rack is often left in place for the sake of convenience, even when it is
no longer needed. At a speed of 100-120 km/h your vehicle will use about
12% more fuel as a result of the extra wind resistance caused by the roof
rack even when it is not in use.
Save electricity
The engine activates the alternator, which produces electricity. With the
need for electricity, fuel consumption is also increased. Because of this, al-
ways turn off electrical components when you do not need them. Examples
of components that use a lot of electricity are: the fan at high speeds, the
rear window heating or the seat heaters*.
Note
● If you vehicle has Start-Stop, it is not recommended to disconnect this
function.
● It is recommended to close the windows when driving at more than 60
km/h
● Do not drive with your foot resting on the clutch pedal, as the pressure
can make the plate spin, more fuel will be used and it can burn the clutch
plate lining, causing a serious fault.
● Do not hold the vehicle on a hill with the clutch, use the foot brake or
hand brake, using the latter to start. The fuel consumption will be lower and
you will prevent the clutch plate from being damaged.
● On descents, use the engine brake, changing to the gear that is more
suitable for the slope. The fuel consumption will be lower and the brakes
will not suffer.
197
Trailer towing
Where possible, operate the trailer with the maximum permitted drawbar
load on the ball joint of the towing bracket, but do not exceed the specified
limit.
Tyre pressure
Check the tyre pressures on your vehicle, and adjust for “full load” condi-
tions (refer to the sticker listing the tyre pressures on the door pillar). It may
also be necessary to adjust the tyre pressures on the trailer according to the
recommendations of the trailer manufacturer.
Exterior mirrors
Check whether you can see enough of the road behind the trailer with the
standard mirrors. If this is not the case you should have additional mirrors
fitted. The two exterior mirrors should be fitted on folding arms. Adjust the
mirrors to give sufficient rear vision.
Headlights
Before starting a journey, check the headlight beam settings with the trailer
hitched up. If necessary, alter the height of the headlight beams by means
of the headlight range control. See ⇒ page 119.
Power supply
When you remove the ignition key, the power supply to the trailer is inter-
rupted.
Removable ball joint coupling
Vehicles with a factory-fitted towing bracket are equipped with a removable
ball joint coupling. This is stored in the spare wheel well in the luggage
compartment together with the necessary fitting instructions.
Note
If you frequently tow, we recommend you also have the vehicle serviced be-
tween services. Notes on towing
Towing a trailer involves additional attention by the driver.
Weight distribution
The weight distribution of a loaded trailer with an unladen vehicle is very
unfavourable. However, if this cannot be avoided, drive extra slow to allow
for the unbalanced weight distribution.
Speed
The stability of the vehicle and trailer is reduced with increasing speed.
Therefore, it is advisable not to drive at the maximum permissible speed in
unfavourable road, weather or wind conditions. This especially applies
when driving downhill.
You should always reduce speed immediately if the trailer shows the slight-
est sign of swaying. Never try to stabilise the trailer by accelerating.
Anticipate hazards and brake in good time. If towing a trailer with an inertia
brake, first brake gently and then harder. This will prevent brake tapping by
the trailer wheels when they lock. Select a low gear in due course before go-
ing down a steep downhill. This enables you to use the engine braking to
slow down the vehicle.
Swaying and pitching can be reduced by stabiliser aids. We recommend
having stabiliser aids installed when towing trailers with a high trailer
weight. They can be purchased and installed at a Technical Service.
Reheating
When climbing long hills in hot weather with the engine running fast in low
gear, you should keep an eye on the coolant temperature gauge ⇒ page 60.
Reduce speed immediately if the needle moves to the right end of the scale.
If the temperature warning lamp in the instrument panel should start
flashing, stop the vehicle and let the engine cool down by running it at
idling speed for a few minutes.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
211
Vehicle maintenance and cleaning
Use an industrial cleaner to remove brake dust. Any damage to the paint on
steel wheel rims should be repaired before starting to rust.
WARNING
● Never wash tyres with a cylindrical jet. Even at large spraying distan-
ces and short cleaning times, visible and invisible damage can occur to
the tyres. This may cause an accident.
● Water, ice and salt on the brakes can reduce braking efficiency. Risk
of accident. Directly after washing, avoid sudden and sharp braking.
“Dry” the brakes by braking several times ⇒ page 191.
Alloy wheel rims
Every two weeks
– Wash salt and brake dust from alloy wheels.
– Use an acid free detergent to clean the wheel rims.
Every three months
– Apply a hard wax compound to the wheels.
Alloy wheels require regular attention to preserve their appearance. If road
salt and brake dust are not often removed, the aluminium finish will be im-
paired.
Always use an acid-free detergent for alloy wheel rims.
Car polish or other abrasive agents should not be used. If the protective
coating is damaged, e.g. by flying stones, the damaged area should be re-
paired immediately.
WARNING
● Never wash tyres with a cylindrical jet. Even at large spraying distan-
ces and short cleaning times, visible and invisible damage can occur to
the tyres. This may cause an accident.
● Water, ice and salt on the brakes can reduce braking efficiency. Risk
of accident. Directly after washing, avoid sudden and sharp braking.
“Dry” the brakes by braking several times ⇒ page 191.
Underbody protection
The vehicle underbody is coated to protect it from chemical
and mechanical damage.
The protective coating can be damaged when driving. We recommend you
to check the protective coating under the body and on the running gear, and
reinstated if necessary, before and after the winter season.
We recommend you to go to your Authorised Service Centre to carry out re-
pair work and additional anti-corrosion work.
WARNING
Do not apply underseal or anti-corrosion coatings to the exhaust pipes,
catalytic converter or the heat shields on the exhaust system. The heat of
the exhaust system or the engine could cause them to ignite. Risk of fire.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
219
Checking and refilling levels
CAUTION
● Petrol with standard EN 228 may be mixed with small quantities of etha-
nol. However, bioethanol fuels available at commercial establishments with
reference E50 or E85, which contain a high percentage of ethanol, may not
be used, as they will damage the fuel system.
● Even one tankful of leaded fuel would permanently impair the efficiency
of the catalytic converter.
● High engine speed and full throttle can damage the engine when using
petrol with an octane rating lower than the correct grade for the engine.
For the sake of the environment
Just one full tank of leaded fuel would seriously impair the efficiency of the
catalytic converter.
Petrol additives
Petrol additives improve the quality of the petrol.
The quality of the petrol influences the performance, power and life of the
engine. For this reason, you should use good quality petrol containing addi-
tives. These additives will help to prevent corrosion, keep the fuel system
clean and prevent deposits from building up in the engine.
If good quality petrol with additives is not available or engine problems oc-
cur, the required additives must be added during refuelling. Diesel
Diesel*
Diesel fuel must conform to DIN EN 590 (EN = “European Standard”). It
must have a cetane number (CN) of at least 51. The cetane number indi-
cates the ignition quality of the diesel fuel.
Notes on refuelling ⇒ page 217.
Biodiesel*
CAUTION
● Your vehicle is not designed to use biodiesel fuel. Never, under any cir-
cumstances refuel with biodiesel. The use of biodiesel fuel could damage
the engine and the fuel system. The addition of biodiesel to diesel fuel by
the diesel manufacturer in accordance with standard EN 590 or DIN 51628
is authorised and will not cause damage to the engine or the fuel system.
● The diesel engine has been designed to be used exclusively with diesel
fuel conforming to standard EN 590. Never refuel or use petrol, kerosene,
fuel oil or any other type of fuel. If you accidentally fill up the vehicle with
the wrong type of fuel, do not start the engine. Seek assistance from speci-
alised personnel. The composition of these fuels may severely damage the
fuel system and the engine.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
221
Checking and refilling levels
Opening the bonnet
Fig. 165 Release catch
under the bonnet
Before opening the bonnet make sure that the windscreen wiper
arms are not lifted away from the glass. Otherwise the paint may
be damaged.
– Lift the bonnet slightly ⇒
.
– Press the release catch under the bonnet upwards ⇒ fig. 165.
This will release the arrester hook under the bonnet.
– Open the bonnet.
The bonnet is held in position by a gas-filled strut.
WARNING
Never open the bonnet if you see steam or drips of coolant being re-
leased from the engine compartment. Failure to comply could result in
burns. Wait until no steam or coolant can be seen before opening the
bonnet.
Work in the engine compartment
Extra caution is necessary when working on components in
the engine compartment.
Always be aware of the danger of injury and scalding as well as the risk of
accident or even fire when working in the engine compartment (e.g. when
checking and refilling fluids). Always observe the warnings listed below
and follow all general safety precautions. The engine compartment of the
vehicle is a potentially hazardous area ⇒
WARNING
● Switch the engine off.
● Remove the ignition key.
● Apply the handbrake firmly.
● If your vehicle is equipped with a manual gearbox, place the gear lev-
er in neutral. If you are driving an automatic vehicle, place the selector
lever in position P.
● Wait for the engine to cool down.
● Children should not be allowed to approach the engine compartment.
● Never spill liquids used for vehicle operation on the engine compart-
ment, as these may catch fire (e.g. coolant).
● Take care not to cause short circuits in the electrical system, especial-
ly when working on the battery.
● Never touch the radiator fan while the engine is hot, as the fan could
start up suddenly.
● Never open the expansion tank when the engine is hot. The cooling
system is under pressure.
● Protect face, hands and arms from any hot steam or hot coolant fluid
released by covering the cap with a large, thick rag when opening the ex-
pansion tank.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications
228Checking and refilling levels
Radiator fan
The radiator fan can start running spontaneously.
The auxiliary fan can continue to run for as long as 10 minutes after stop-
ping the engine, even after the ignition is switched off. It may also start run-
ning suddenly ⇒
after some while if
● Stored heat raises the coolant temperature, or
● The hot engine compartment is additionally heated up by the sun.
WARNING
When working in the engine compartment be aware that the radiator fan
may start running suddenly, leading to the risk of injury.
Washer fluid and windscreen wiper blades
Windscreen washer system
Plain water is not sufficient for the windscreen washer sys-
tem.
Fig. 169 In the engine
compartment: Cap of
windscreen washer fluid
reservoir.
The container for the windscreen washer contains the cleaning fluid for the
windscreen and the headlight washer system*. The container is located in
the engine compartment (front left). The filler cap is marked with the symbol
⇒ fig. 169.
The capacity of the container is listed in ⇒ page 290.
Plain water on its own is not enough to clean the glass properly. It is there-
fore advisable to add a suitable washer fluid additive (with wax solvent) to
the water. A washer fluid with freeze-resistant additive should be used in
winter.
233
Checking and refilling levels
WARNING (Continued)
● A highly explosive mixture of gases is released when the battery is
under charge. The batteries should be charged in a well-ventilated room
only.
● Keep children away from acid and batteries.
● Before working on the electrical system, you must switch off the en-
gine, the ignition and all consumers. The negative cable on the battery
must be disconnected. When a light bulb is changed, you need only
switch off the light.
● Deactivate the anti-theft alarm by unlocking the vehicle before you
disconnect the battery! The alarm will otherwise be triggered.
● When disconnecting the battery from the vehicle electrical system,
disconnect first the negative cable and then the positive cable.
● Switch off all electrical consumers before reconnecting the battery.
Reconnect first the positive cable and then the negative cable. Never re-
verse the polarity of the connections. This could cause an electrical fire.
● Never charge a frozen battery, or one which has thawed. This could
result in explosions and chemical burns. Always replace a battery which
has frozen. A flat battery can freeze at temperatures around 0 °C.
● Ensure that the vent hose is always connected to the battery.
● Never use a defective battery. This could cause an explosion. Replace
a damaged battery immediately.
CAUTION
● Never disconnect the battery if the ignition is switched on or if the en-
gine is running. This could damage the electrical system or electronic com-
ponents.
● Do not expose the battery to direct sunlight over a long period of time,
as the intense ultraviolet radiation can damage the battery housing.
● If the vehicle is left standing in cold conditions for a long period, protect
the battery from freezing. If it freezes it will be damaged. Charging the battery
A fully-charged battery is important for reliable starting.
– Note the warnings ⇒
in Important safety warnings for han-
dling a vehicle battery on page 232 and ⇒ .
– Switch off the ignition and all electrical equipment.
– Only if fast-charging: both battery cables must be disconnected
(first the negative cable, then the positive cable).
– Connect the charger cables to the battery terminals, noting the
colour code (red = positive; black or brown = negative).
– Now connect the battery charger to the power socket and switch
on.
– After charging the battery: switch off the battery charger and
disconnect the power point cable.
– Finally disconnect the charger cables from the battery.
– If necessary, reconnect both battery cables to the battery (first
the positive cable, then the negative cable).
When charging with a low current (for instance with a small battery charger)
the battery does not normally have to be disconnected. However, both bat-
tery cables must be disconnected before fast-charging the battery with a
high current. However, always follow the instructions given by the manufac-
turer of the battery charger.
The fast-charging procedure for a battery is dangerous ⇒
in Important
safety warnings for handling a vehicle battery on page 232, as it requires a
special charger and the corresponding level of knowledge. We therefore rec-
ommend that this work should only be performed by a qualified workshop.
Safety FirstOperating InstructionsPractical TipsTechnical Specifications