2008 MERCEDES-BENZ B-CLASS HATCHBACK service

Tyres and wheels
178 MOExtended run-flat system*
The MOExtended run-flat system allows you
to continue driving the vehicle even when one
or more tyres lose all air pressure.
The MOExtended run-flat system may only be
used in combination with the tyre pressure
loss warning system and only on wheels spe-
cifically tested and approved by Mercedes-
Benz.
i Vehicles with MOExtended run-flat sys-
tem are not equipped with the TIREFIT
kit* 24
.
Therefore, it is recommended that you
equip your vehicle additionally with the
TIREFIT kit* when fitting tyres that do not
feature run-flat properties, e.g. winter
tyres.
i A TIREFIT kit* is available from any quali-
fied specialist workshop, e.g. a Mercedes-
Benz Service Centre.
You will find notes on driving with a flat tyre
in the "Practical advice" section
(Y page 262). Tyre tread
G
Risk of accident
Bear in mind that:
R tyre grip decreases rapidly on wet roads
when the tread depth is less than 3 mm.
Thus, you should replace tyres that have
insufficient tread.
R winter tyres should be replaced when the
tread depth is 4 mm or less as they will
no longer provide adequate grip.
R the tread on a tyre may not wear evenly.
Thus, you should regularly check the
tread depth and the condition of the
tread across the entire width of all tyres.
If necessary, turn the steering wheel so
that you can see the tyre tread more eas-
ily.
Otherwise, you could lose control of the
vehicle and cause an accident due to the
reduced grip of the tyres on the road. Tyre pressures
i You will find a table of tyre pressures for
various operating conditions on the inside
of your vehicle's fuel filler flap.
The valid value for the spare wheel* is sta-
ted on the spare wheel and in the technical
data section. G
Risk of accident
Tyre pressure that is either too high or too
low has a negative effect on the vehicle’s
driving safety, which could lead you to
cause an accident. Therefore, you should
regularly check the pressure of all the tyres
(including the spare tyre*), particularly
prior to long trips, and correct the pressure
as necessary.
To test tyre pressure, use a suitable pressure
gauge. The outer appearance of a tyre does
not permit any reliable conclusion about the
tyre pressure. G
Risk of accident
Should the tyre pressure drop repeatedly:
24 Only for certain countries. Operation
* optional
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Tyres and wheels
179R
check the tyre for foreign bodies.
R check whether the wheel is losing air or
the valve is leaking.
Tyre pressure that is too low has a negative
effect on the vehicle's active safety, which
could lead to your causing an accident.
Tyre pressure changes by approximately
0.1 bar for every 10 °C change in ambient
temperature.
If you measure the tyre pressure in enclosed
spaces where the temperature differs from
the outside temperature, you will have to cor-
rect the measured value accordingly.
When the vehicle is driven, the tyre tempera-
ture, and with it the tyre pressure, will
increase depending on the road speed and
the load on the tyres.
Therefore, you should only correct tyre pres-
sures when the tyres are cold.
The pressure of warm tyres should only be
corrected if it is too low for the current oper-
ating conditions. Driving with tyre pressure that is too high or
too low can:
R
shorten the service life of the tyres
R increase the likelihood of tyre damage
R have a negative effect on handling charac-
teristics (e.g. by causing aquaplaning)
i The tyre pressure values given for low
loads are minimum values which offer you
good ride comfort characteristics.
However, you can also use the values given
for higher loads. These are permissible and
will not adversely affect the running of the
vehicle. H
Environmental note
Check the tyre pressure regularly, at least
every 14 days. Tyre pressure loss warning system
While the vehicle is in motion, the tyre pres-
sure loss warning system monitors the set
tyre pressure using the rotational speed of
the wheels. This enables the system to detect
significant pressure loss in a tyre. If the speed
of rotation of a wheel changes as a result of
a loss of pressure, a corresponding warning
message will appear in the multi-function dis-
play. G
Risk of accident
The tyre pressure loss warning system does
not warn you of an incorrectly set tyre pres-
sure. The table on the inside of the fuel filler
flap will help you decide whether the tyre
pressures should be corrected.
The tyre pressure loss warning system does
not replace the need to regularly check
your vehicle's tyre pressures, since an even
loss of pressure on several tyres at the
same time cannot be detected by the tyre
pressure loss warning system.
The tyre pressure loss warning system is
not able to warn you of a sudden loss of
pressure, e.g. if the tyre is penetrated by a
foreign object.
In the event of a sudden loss of pressure,
bring the vehicle to a halt by braking care- Operation
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Winter driving
181Interchanging the wheels
G
Risk of accident
Interchange the front and rear wheels only
if they have the same dimensions: for exam-
ple size, offset, etc.
After every wheel interchange/change,
have the tightening torque checked at a
qualified specialist workshop that has the
necessary specialist knowledge and tools
to carry out the work required. Mercedes-
Benz recommends that you use a
Mercedes-Benz Service Centre for this pur-
pose. In particular, work relevant to safety
or on safety-related systems must be car-
ried out at a qualified specialist workshop.
The wheels could work loose if they are not
tightened to a torque of 130 Nm.
For safety reasons, Mercedes-Benz recom-
mends that you only use wheel bolts of the
correct size which have been approved for
Mercedes-Benz vehicles.
The wear patterns on the front and rear tyres
differ, depending on the operating conditions.
Interchange the wheels before a clear wear
pattern has formed on the tyres. Front tyres
typically wear more on the shoulders and the
rear tyres in the centre. Interchange the wheels every 5,000 km to
10,000 km depending on the degree of tyre
wear, provided that the vehicle has the same
size front and rear tyres. Do not reverse the
direction of tyre rotation.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is changed. Check the tyre pressure and, if
necessary, restart the tyre pressure loss
warning system. Winter driving
Points to remember
Have your vehicle winterproofed at a qualified
specialist workshop, e.g. at a Mercedes-Benz
Service Centre, at the onset of winter. Winter tyres
Use winter tyres at temperatures below +7 °C
and on snow or ice-covered roads. Only then
can the effect of the ABS and ESP ®
driving
systems be ensured in winter too.
Use winter tyres of the same make and tread
on all wheels to maintain safe handling char-
acteristics. G
Risk of accident
Winter tyres with a tread depth of less than
4 mm must be replaced immediately. They
are no longer suitable for winter use and
can no longer provide sufficient grip. This
could cause you to lose control of your
vehicle and cause an accident.
Always observe the maximum permitted
speed specified for the winter tyres you have
fitted. If you fit winter tyres which have a
lower maximum permitted speed than that of
the vehicle, affix an appropriate warning sign Operation
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Winter driving
182
in the driver's field of vision. This can be
obtained at a qualified specialist workshop,
e.g. from a Mercedes-Benz Service Centre.
Under these circumstances, you should also
restrict the maximum speed of the vehicle
using permanent Speedtronic* 25
to the max-
imum permissible speed for the winter tyres
(Y page 119).
Once you have fitted the winter tyres:
X Check the tyre pressures (Y page 178).G
Risk of accident
If you fit the spare wheel* when driving with
winter tyres, bear in mind that driving sta-
bility will be impaired owing to unstable
cornering characteristics caused by the dif-
ferent tyres. You should therefore adapt
your driving style and drive carefully.
Have the spare wheel* replaced at the
nearest qualified specialist workshop
which has the necessary specialist knowl-
edge and tools to carry out the work
required. Mercedes-Benz recommends
that you use a Mercedes-Benz Service
Centre for this purpose. In particular, work
relevant to safety or on safety-related sys- tems must be carried out at a qualified spe-
cialist workshop.
Snow chains
For safety reasons, Mercedes-Benz recom-
mends that you only use snow chains which
have been specially approved for your vehicle
by Mercedes-Benz, or are of a corresponding
standard of quality.
! Information about the use of snow chain-
compatible AMG winter tyres is applicable
for AMG tyres. Use of snow chains is only
permissible with these tyres.
If you intend to fit snow chains, please bear
the following points in mind:
R snow chains cannot be fitted to all wheel/
tyre combinations.
R snow chains must not be fitted to emer-
gency spare wheels, e.g. on a "Minispare"
emergency spare wheel.
R Fit snow chains only in pairs and only to the
front wheels. Comply with the manufactur-
er's installation instructions.
! Vehicles with 17" tyres You may only fit snow chains as a pulling-
away aid. Only use fine-link snow chains.
When snow chains are fitted, you may only
drive straight ahead. The snow chains could
otherwise come into contact with the body-
work when you turn the front wheels.
When snow chains are fitted, you cannot use
Active Park Assist* (Y page 122).
Do not exceed the maximum permissible
speed of 50 km/h. Winter driving
G
Risk of accident
Do not shift down for additional engine
braking on a slippery road surface. This
could cause the drive wheels to lose their
grip and the vehicle could skid.
You should drive particularly carefully on slip-
pery road surfaces. Avoid sudden accelera-
tion, steering and braking manoeuvres.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
25 Only available for certain countries. Operation
* optional
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Driving
tips 183
X
Vehicles with manual transmission: engage
neutral.
X Vehicles with AUTOTRONIC*: shift the
selector lever to N.
X Try to bring the vehicle under control using
corrective steering. Driving tips
Rolling with the engine switched off
G
Risk of accident
Never switch the engine off while the vehi-
cle is in motion.
There is no power assistance for the steer-
ing and the service brake when the engine
is not running.
You will require considerably more effort to
steer and brake and you could therefore
lose control of the vehicle and cause an
accident. Braking
G
Risk of accident
Do not change down for additional engine
braking on a slippery road surface. This
could cause the drive wheels to lose their
grip and the vehicle could skid. G
Risk of accident
Make sure that other road users are not
endangered by your braking. Downhill gradients On long and steep downhill stretches, espe-
cially if the vehicle is laden or towing a trailer,
you must shift to a lower gear in good time or,
on vehicles with AUTOTRONIC*, select shift
range
1,2or 3.
i This also applies if you have activated
cruise control* or Speedtronic*.
This will use the braking effect of the engine,
so less braking will be required to maintain
the speed. This relieves the load on the brake
system and prevents the brakes from over-
heating and wearing too quickly. If you need
additional braking, depress the brake pedal
repeatedly rather than continuously.
Heavy and light loads If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately, but
drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
G
Risk of accident
Never depress the brake pedal continu-
ously while the vehicle is in motion, e.g.
never cause the brakes to rub by applying
constant slight pedal pressure. This causes
the brake system to overheat, increases Operation
* optional
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Driving ab
road 185Driving on wet roads
If water has accumulated to a certain depth
on the road surface, there is a danger of aqua-
planing occurring, even if:
R you drive at low speeds
R the tyres have adequate tread depth
For this reason, do not drive in tyre ruts, and
brake carefully. Driving on flooded roads
If you have to drive on stretches of road on
which water has collected, please bear in
mind that:
R the maximum permitted still water depth is
25 cm.
R you should drive no faster than at walking
pace.
! Bear in mind that vehicles travelling in
front or in the opposite direction create
waves. This may cause the maximum per-
missible water depth to be exceeded.
Failure to observe these notes may result
in damage to the engine, electrical systems
and transmission. Driving abroad
Points to remember
An extensive Mercedes-Benz Service network
is also available in other countries. The
Service Hotline's current telephone numbers
for use when you are abroad are to be found
in the "Service24h" chapter of the Service
Booklet.
Only low-octane fuel is available in certain
countries.
You can find further information about fuel
grades on (Y page 168). Symmetrical dipped beam
If your journey takes you to countries where
vehicles are driven on sides of the road oppo-
site to the country in which the vehicle is reg-
istered, your headlamps must be switched to
symmetrical dipped beam. Oncoming traffic
will be dazzled less.
X Have the headlamps switched over at a
qualified specialist workshop, e. g. a
Mercedes-Benz Service Centre. G
Risk of accident
Remember to set the headlamps back to
asymmetrical dipped beam when you return to driving on the same side of the
road as that of the country in which your
vehicle was registered. You may otherwise
dazzle the oncoming traffic and could cause
an accident. Operation
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Trailer towing*
186 Trailer towing*
Fitting the ball coupling
X Make a note of the ball coupling key num-
ber.
i You can use this number to obtain a
replacement key from a Mercedes-Benz
Service Centre. G
Risk of injury
If the ball coupling does not engage cor-
rectly when it is mounted, the vehicle/
trailer combination is not secured and the
trailer could come loose. This could cause
an accident. Fit the ball coupling carefully
and make sure that it engages in position
correctly.
Vehicles without ECO start/stop func-
tion: the attachable ball coupling is on the
right of the stowage compartment in the lug-
gage compartment (Y page 160).
X Open the stowage compartment on the
right-hand side of the luggage compart-
ment.
X Fold the trim downwards. Vehicles without ECO start/stop function
1
Ball coupling
2 Retainer strap
X Undo retainer strap 2.
X Remove ball coupling 1from the ball cou-
pling recess.
Vehicles with ECO start/stop function*:
the attachable ball coupling is in the ball cou-
pling recess in the stowage well underneath
the luggage compartment floor
(Y page 202).
X Open the luggage compartment floor. Vehicles with ECO start/stop function
1
Ball coupling
2 Ball coupling recess
X Remove ball coupling 1from the ball cou-
pling recess.2 1
Protective cap Operation
* optional
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Trailer towing*
1881
Trailer power socket
X Fold trailer power socket 1down. G
Risk of accident
The ball coupling is only securely mounted
when the green mark on the handwheel is
aligned with the green area on the ball cou-
pling and the key can be removed. If the ball
coupling is not securely mounted, it may
come loose.
The ball coupling must be locked and the
key must be removed when towing a trailer.
This is the only way to guarantee that the
ball coupling is secured and cannot come
loose while the vehicle is in motion. If the
ball coupling cannot be locked and the key
cannot be removed, remove the ball cou-
pling and clean it. If the ball coupling can still not be fitted
(locked) after it has been cleaned, remove
the ball coupling. The trailer coupling must
then not be used to tow a trailer, as safe
operation is not guaranteed.
Have the entire trailer coupling checked at
a qualified specialist workshop. Mercedes-
Benz recommends that you use a
Mercedes-Benz Service Centre for this pur-
pose. In particular, work relevant to safety
or on safety-related systems must be car-
ried out at a qualified specialist workshop. Notes on towing a trailer
G
Risk of accident
When reversing the vehicle towards the
trailer, make sure there is nobody between
the trailer and the vehicle.
Couple and uncouple the trailer carefully. If
you do not couple the trailer to the towing
vehicle correctly, the trailer could become
detached.
Make sure that the following values are not
exceeded: R
the permissible trailer drawbar nose-
weight
R the permissible trailer load
R the permissible rear axle load of the tow-
ing vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
You will find the applicable permissible val-
ues, which must not be exceeded, in the
vehicle documents.
You will find the values approved by the
manufacturer on the vehicle identification
plates and those for the towing vehicle in
the "Technical data" section.
You will find installation dimensions and loads
in the "Technical data" section
(Y page 289).
The maximum permissible trailer drawbar
noseweight on the ball coupling is 75 kg.
However, the actual drawbar load must not
exceed the value given on the trailer coupling
and trailer identification plates. The lowest
weight applies.
! Use a noseweight as close as possible to
the maximum permissible noseweight. Do Operation
* optional
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