winter tires MERCEDES-BENZ R-Class 2012 W251 Owner's Manual

Replacing the wiper blades ............125
Switching on/off ........................... 124
Winter driving
Important safety notes ..................324
Slippery road surfaces ...................170
Snow chains .......................... 169, 325
Winter operation
Radiator cover ............................... 283
Winter tires
M+S tires ............................... 169, 324
Wiper blades
Cleaning ......................................... 291
Important safety notes ..................125
Replacing (rear window) ................126
Replacing (windshield) ...................126
Wooden trim (cleaning
instructions) ...................................... 29320Index

section must never be exploited in a reckless
or dangerous manner which could jeopardize
the user's safety or the safety of others.
Always adjust your driving style to the
prevailing road and weather conditions and
keep a safe distance to other road users and
objects on the street.
If a driving system malfunctions, other driving
safety systems may also switch off. Observe
indicator and warning lamps that may come
on as well as messages in the multifunction
display that may appear.
i Please note that the driving safety
systems described only work as effectively
as possible when there is adequate contact
between the tires and the road surface. Pay
particular attention to the information
regarding tires, recommended minimum
tire tread depths etc. in the "Wheels and
tires" section ( Y page 322).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary,
snow chains. Only in this way will the
driving safety systems described in this
section work as effectively as possible.
ABS (Anti-lock Braking System)
Important safety notes
i Observe the "Important safety notes"
section ( Y page 64).
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
ABS works from a speed of about
5 mph(8 km/h) upwards, regardless of road-
surface conditions. ABS works on slippery
surfaces, even when you only brake gently.
GWARNING
If the ABS malfunctions, other driving systems
such as the BAS or the ESP ®
are also switched
off. Observe indicator and warning lamps that
may come on as well as messages in the
multifunction display that may appear.
If the ABS malfunctions, the wheels may lock
during hard braking, reducing the steering
capability and extending the braking distance.
The ! warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
XIf ABS intervenes: continue to depress the
brake pedal with force until the braking
situation is over.XTo make a full brake application:
depress the brake pedal with full force.
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving.
GWARNING
Do not pump the brake pedal. Use firm, steady
brake pedal pressure instead. Pumping the
brake pedal defeats the purpose of the ABS
and significantly reduces braking
effectiveness.
BAS (Brake Assist System)
i Observe the "Important safety notes"
section ( Y page 64).
BAS operates in emergency braking
situations. If you depress the brake pedal
quickly, BAS automatically boosts the braking
force, thus shortening the stopping distance.
XKeep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
Driving safety systems65SafetyZ

at high speeds. This improves the grip of the
brake pads.GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
You can find a description of Brake Assist
(BAS) on ( Y page 65).
Parking brake
If you drive on wet roads or dirt-covered
surfaces, road salt and/or dirt could get into
the parking brake.
In order to prevent corrosion and a reduction
in the braking power of the parking brake,
observe the following:
R Gently depress the parking brake from time
to time before beginning the journey.
R Drive a distance of approximately 110 yds
(100 m) with a maximum speed of 12 mph
(20 km/h).
GWARNING
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle's brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or
in conditions in which hydroplaning can occur
you must drive in the following manner:
R reduce your speed
R avoid ruts
R brake carefully
Driving on flooded roads
! Do not drive through flooded areas.
Check the depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage.
Do not allow water to enter the passenger
compartment or the engine compartment. If
you have to drive through a stretch of
standing water, please be aware the
following:
R the depth of the water must not exceed
10 inches (25 cm) for calm water
R you should drive no faster than at walking
pace.
i For vehicles with AIRMATIC package:
if you have set the raised level before
driving through a stretch of standing water,
the maximum water depth is 12 inches
(30 cm).
Winter driving
Important safety notes
GWARNING
If the vehicle becomes trapped in snow,
ensure that snow is kept away from the
exhaust pipe and from around the vehicle as
long as the engine is running. Otherwise,
poisonous carbon monoxide (CO) may enter
168Driving tipsDriving and parking

the vehicle, resulting in loss of consciousness
and even death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
At the onset of winter, have your vehicle
winterproofed at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.
i Vehicles with a diesel engine: do not
cover the radiator, e.g. with a protective
cover. The measuring function of the
Onboard Diagnosis System may otherwise
provide inaccurate values. Some of these
values are required by law and must
therefore always be accurate.
Winter tires
At temperatures below 45 ‡(+7 †), use
winter tires or all-season tires. Both types of
tire are identified by the M+S marking.
Only winter tires bearing the i snowflake
symbol in addition to the M+S marking
provide the best possible grip in wintry road
conditions. Only these tires will allow driving
safety systems such as ABS and ESP ®
to
function optimally in winter, as these tires
have been designed specifically for driving on
snow.
Use M+S tires of the same make and tread on
all wheels to maintain safe handling
characteristics.
GWARNING
M+S tires with a tread depth of less than 1
/ 6
inch (4 mm) must be replaced immediately.
They are no longer suitable for use in winter.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
Once you have mounted the winter tires:XCheck the tire pressures ( Y page 329).XRestart the tire pressure monitor
( Y page 331).GWARNING
If you use your spare wheel when M+S tires
are mounted on the other wheels, be aware
that the difference in tire characteristics
impairs cornering ability and reduces driving
stability. Adapt your driving style accordingly.
Have the spare wheel replaced by a normal
wheel with an M+S tire at the nearest
Mercedes-Benz Center.
Snow chains
For safety reasons, Mercedes-Benz
recommends 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.
! Vehicles with the Adaptive Damping
System (ADS): do not drive in ADS SPORT
mode if snow chains have been mounted.
The vehicle may otherwise be damaged.
! There is not enough space for snow
chains on some wheel sizes. Observe the
information under "Tires and wheels" in the
"Technical Data" section to avoid damage
to the vehicle or the wheels.
R Only use snow chains when driving on
roads completely covered by snow. Do not
exceed the maximum permissible speed of
30 mph (50 km/h). Remove the snow
chains as soon as possible when you are no
longer driving on snow-covered roads.
R Local regulations may restrict the use of
snow chains. Applicable regulations must
be observed if you wish to mount snow
chains.
R Snow chains must not be mounted on
emergency spare wheels.
Driving tips169Driving and parkingZ

If indicator lamp ; is lit:XPress button :.
Indicator lamp ; flashes. The vehicle is
lowered to highway level.
While the adjustment is taking place, a
message appears in the multifunction
display, e.g.:
If you press the V, U , * or &
button on the multifunction steering wheel,
the message will disappear.
Once highway level has been reached,
indicator lamp ; goes out. A message
appears in the multifunction display for
approximately five seconds, e.g.:
The level is automatically raised from high-
speed level to highway level if the speed falls
below 40 mph (64 km/h). The level is
automatically taken up to highway level if you
drive faster than 25 mph (40 km/h).
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are
permanently driven. Together with ESP ®
and
4ETS , it improves the traction of your vehicle
whenever a drive wheel spins due to
insufficient grip.
GWARNING
If a drive wheel is spinning due to insufficient
traction:
R While driving off, apply as little throttle as
possible.
R While driving, ease up on the accelerator
pedal.
R Adapt your speed and driving style to the
prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents
resulting from excessive speed.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz Limited Warranty. All
wheels must remain either on the ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tires ( M+S tires), with snow
chains if necessary.
! When testing the parking brake, operate
the vehicle only briefly (for a maximum of
ten seconds) on a brake test dynamometer.
When doing this, turn the key to position
0 or 1 in the ignition. Failure to do this can
cause damage to the drive train or the
brake system.
! Function or performance tests may only
be performed on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center
beforehand. You could otherwise damage
the drive train or the brake system.
Driving systems183Driving and parkingZ

XMake sure the vehicle is stationary and the
ignition is switched off.XTurn the SmartKey to position
2 (Y page 145) in the ignition lock.
Use the SmartKey instead of the Start/
Stop button on vehicles with KEYLESS-GO.XDepress and hold the brake pedal.XShift the automatic transmission to
position N.XRelease the brake pedal.XRelease the parking brake.XSwitch off the ignition and leave the
SmartKey in the ignition lock.
! Make sure that:
R the side windows and the sliding sunroof
are fully closed.
R the ventilation/heating is switched off
(the OFF button has been pressed).
R the windshield wiper switch is in position
0 .
Otherwise, the vehicle might be damaged.
After using an automatic car wash, wipe off
wax from the windshield and the wiper
blades. This will prevent smears and reduce
wiping noises caused by residue on the
windshield.
Washing by hand
Carefully remove all deposits of road salt as
soon as possible when driving in winter.
Also, clean the insides of the wheels when
washing the underbody of the vehicle.
XDo not use hot water and do not wash the
vehicle in direct sunlight.XUse a soft car sponge for cleaning.XUse a gentle cleaning agent, e.g. a
Mercedes-Benz approved car shampoo.XWash down the vehicle with a gentle water
jet.XDo not point the water jet directly at the air
inlets.XUse plenty of water and rinse the sponge
frequently.XRinse the vehicle with clean water and dry
it thoroughly with a chamois.XDo not allow the cleaning agent to dry on
the paintwork.
Power washers
GWARNING
Do not use power washers with circular-jet
nozzles (dirt grinders) to clean your vehicle, in
particular the tires. You could otherwise
damage the tires and cause an accident.
! Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about
the correct distance is available from the
equipment manufacturer.
Move the power washer nozzle around
when cleaning your vehicle.
Do not aim directly at any of the following:
R tires
R door gaps, roof gaps, joints etc.
R electrical components
R battery
R connectors
R lights
R seals
R trim elements
R ventilation slots
Damaged seals or electrical components
can lead to leaks or failures.
Cleaning the wheels
! Do not use acidic wheel cleaning products
to remove brake dust. This could damage
wheel bolts and brake components.
! Do not park the vehicle for an extended
period straight after cleaning it, particularly
after having cleaned the wheels with wheel
cleaner. Wheel cleaners could cause
increased corrosion of the brake discs and
brake pads/linings. For this reason, you
should drive for a few minutes after
Care289Maintenance and careZ

Flat tire
Preparing the vehicle
Your vehicle may be equipped with a
collapsible spare wheel or MOExtended tires
(tires with run-flat properties) ( Y page 309).
i Vehicle preparation is not necessary on
vehicles with MOExtended tires.
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from an
authorized Mercedes-Benz Center.
XVehicles with the AIRMATIC package: make
sure that highway level is selected
( Y page 180).XStop the vehicle as far away as possible
from traffic on solid, non-slippery and level
ground.XSwitch on the hazard warning lamps.XFirmly depress the parking brake.XBring the front wheels into the straight-
ahead position.XMove the DIRECT SELECT lever to P.XSwitch off the engine.XVehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock.XVehicles with KEYLESS-GO: open the
driver's door.
The on-board electronics have status 0,
which is the same as the SmartKey having
been removed.XVehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
( Y page 145).XAll occupants must get out of the vehicle.
Make sure that they are not endangered as
they do so.XMake sure that no one is near the danger
area while a wheel is being changed.Anyone who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.XGet out of the vehicle. Pay attention to
traffic conditions when doing so.XClose the driver's door.
i Only operate the tire inflation compressor
using the socket in the footwell of the
second row of seats ( Y page 268), even if
the ignition is turned off.
An emergency cut-off ensures that the on-
board electrical system voltage does not
drop too low. If the on-board electrical
system voltage is too low, power to the
sockets is automatically cut off. This
ensures that there is sufficient power to
start the engine.
TIREFIT kit
Using the TIREFIT kit
You can use the TIREFIT kit to seal small
punctures, particularly those in the tire tread.
You can use TIREFIT at outside temperatures
down to -4 ‡ (-20 †).
GWARNING
TIREFIT is a limited repair device. TIREFIT
cannot be used for cuts or punctures larger
than approximately 0.16 in (4 mm) and tire
damage caused by driving with extremely low
tire inflation pressure, or on a flat tire, or a
damaged wheel.
Do not drive the vehicle under such
circumstances.
Contact the nearest authorized Mercedes-
Benz Center for assistance or call Roadside
Assistance.
XDo not remove any foreign objects which
have penetrated the tire, e.g. screws or
nails.XRemove the tire sealant bottle, the
accompanying "max. 80 km/h" sticker and
the tire inflation compressor from theFlat tire299Breakdown assistanceZ

GWARNING
The handling characteristics of your vehicle
deteriorate in run-flat mode, for example:
R when cornering
R when braking
R when accelerating rapidly
Adapt your driving style accordingly and avoid
sudden changes in direction and sudden
acceleration, as well as driving over obstacles
(i.e. curbs, potholes), and driving off-road.
This is particularly the case when the vehicle
is heavily laden.
The maximum permissible distance that can
be driven in run-flat mode depends to a large
extent on the loads placed on the vehicle. It
can be shorter due to high speeds, a heavy
load, sudden changes in direction, the road
surface condition, outside temperature, etc.,
or further if you drive carefully and
conservatively.
Do not continue to drive in run-flat mode if:
R you hear banging noises.
R the vehicle starts to shake.
R you see smoke and smell rubber.
R ESP ®
is intervening constantly.
R there are tears in the sidewalls of the tire.
After driving in run-flat mode, you must have
the wheel(s) checked for damage at a
qualified specialist workshop which has the
necessary specialist knowledge and tools to
carry out the work required. The defective tire
must be replaced in every case.
Mercedes-Benz recommends that you use an
authorized Mercedes-Benz Center for this
purpose. In particular, work relevant to safety
or on safety-related systems must be carried
out at a qualified specialist workshop.
i When replacing one or all tires, make sure
that you only use tires marked
MOExtended and of the specified size for
the vehicle.
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from an
authorized Mercedes-Benz Center.
Battery
Important safety notes
In order for the battery to achieve the
maximum possible service life, it must always
be sufficiently charged.
! Have the battery checked regularly at a
qualified specialist workshop, such as an
authorized Mercedes-Benz Center.
Adhere to the service intervals indicated in
the service booklet or ask a qualified
specialist workshop, such as an authorized
Mercedes-Benz Center.
Have the battery charge checked more
frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for
a lengthy period.
Only replace a battery with a battery that has
been recommended by Mercedes-Benz.
Consult an authorized Mercedes-Benz Center
if you wish to leave your vehicle parked for a
long period of time.
GWARNING
Comply with safety precautions and take
protective measures when handling batteries.
Risk of explosionFire, naked flames and
smoking are prohibited
when handling the battery.
Avoid creating sparks.Battery acid is caustic.
Avoid contact with the skin,
eyes or clothing.310BatteryBreakdown assistance

Useful information ............................322
Important safety notes ....................322
Operation ........................................... 322
Winter operation ............................... 324
Tire pressure ..................................... 325
Loading the vehicle ..........................333
Maximum load rating .......................337
Uniform Tire Quality Grading
Standards .......................................... 338
Tire labeling ....................................... 339
Definition of terms for tires and
loading ............................................... 343
Changing a wheel ............................. 346
Wheel and tire combinations ...........347321Wheels and tires

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 24).
Important safety notes
Consult an authorized Mercedes-Benz Center
if you require information on approved and
recommended tires and wheels for summer
and winter operation. Advice on purchasing
and caring for tires is also available there.
GWARNING
Replace rims or tires with the same
designation, manufacturer and type as shown
on the original part. For further information
contact an authorized Mercedes-Benz Center.
If incorrectly sized rims and tires are
mounted, the wheel brakes or suspension
components can be damaged. Also, the
operating clearance of the wheels and the
tires may no longer be correct.
GWARNING
Worn, old tires can cause accidents. If the tire
tread is worn to minimum tread depth, or if
the tires have sustained damage, replace
them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can result
in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or
recommended by Mercedes-Benz, since
previous damage cannot always be
recognized on retreads. The operating safety
of the vehicle cannot be assured when such
tires are used.GWARNING
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possible
damage to your vehicle has occurred, you
should turn on the hazard warning flashers,
carefully slow down, and drive with caution to
an area which is a safe distance from the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle appears
unsafe, have the vehicle towed to the nearest
authorized Mercedes-Benz Center or tire
dealer for repairs.
GWARNING
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
might lose control of the vehicle. Continued
driving with a flat tire or driving at high speed
with a flat tire will cause excessive heat build-
up and possibly a fire.
i Further information about Tires and
wheels can be obtained from any
authorized Mercedes-Benz Center.
Operation
Notes on driving
R If the vehicle is heavily laden, check the tire
pressures and correct them if necessary.
R When parking your vehicle, make sure that
the tires do not get deformed by the curb
or other obstacles. If it is necessary to drive
over curbs, speed humps or similar
elevations, try to do so slowly and at an
obtuse angle. Otherwise, the tires,
particularly the sidewalls, can get
damaged.
322OperationWheels and tires