flat tire MERCEDES-BENZ R-Class 2012 W251 Owner's Guide

Securing the vehicle on level ground
XOn level ground: place chocks or other
suitable items under the front and rear of
the wheel that is diagonally opposite the
wheel you wish to change.
Securing the vehicle on slight downhill gradients
XOn downhill gradients: place chocks or
other suitable items in front of the wheels
of the front and rear axle.
Raising the vehicle
GWARNING
When jacking up the vehicle, only use the jack
which has been specifically approved by
Mercedes-Benz for your vehicle.
The jack is designed exclusively for jacking up
the vehicle at the jacking points built into both
sides of the vehicle. The jack saddle must be
placed centrally under the jacking point. The
jack must always be vertical when in use,
especially on inclines or declines.
The jack is intended only for lifting the vehicle
briefly for wheel changes. It is not suited for
performing maintenance work under the
vehicle. To help avoid personal injury, use the
jack only to lift the vehicle during a wheel
change.
Never get beneath the vehicle while it is
supported by the jack. Keep hands and feet
away from the area under the lifted vehicle.
Always lower the vehicle onto sufficient
capacity jackstands before working under the
vehicle.
Always firmly engage the parking brake and
block the wheels with wheel chocks or other
sizable objects before raising the vehicle with
the jack. Do not disengage the parking brake
while the vehicle is raised.
Make sure that the ground on which the
vehicle is standing and where you place the
jack is solid, level and not slippery. If
necessary, use a large underlay. On slippery
surfaces, such as tiled floors, you should use
a non-slip underlay, for example a rubber mat.
Do not use wooden blocks or similar objects
as a jack underlay. Otherwise, the jack may
not be able to achieve its load-bearing
capacity if it is not at its full height.
Never start the engine when the vehicle is
raised.
Also observe the notes on the jack.XUsing lug wrench :, loosen the bolts on
the wheel you wish to change by about one
full turn. Do not unscrew the bolts
completely.
The jacking points for the jack are located
behind the wheel housings of the front wheels
Flat tire305Breakdown assistanceZ

and in front of the wheel housings of the rear
wheels (arrows).GWARNING
The jack is designed exclusively for jacking up
the vehicle at the jacking points. The jack
saddle must be placed centrally under the
jacking point.
If you do not position the jack correctly in the
jacking point, the vehicle can fall off the jack
and seriously or fatally injure you or others.
! The jack is designed exclusively for
jacking up the vehicle at the jacking points.
Otherwise, your vehicle could be damaged.
XTake ratchet wrench out of the vehicle tool
kit and place it on the hexagon nut of the
jack so that the letters AUF are visible.XPosition jack = at jacking point ;.XMake sure that the base of the jack is
positioned directly under the jacking point.XTurn ratchet wrench ? until jack = sits
completely on jacking point ; and the
base of the jack lies evenly on the ground.XTurn ratchet wrench ? until the tire is
raised a maximum of 1.2 inches (3 cm) off
the ground.
Removing a wheel
XUnscrew the uppermost wheel bolt
completely.XScrew alignment bolt : into the thread
instead of the wheel bolt.XUnscrew the remaining wheel bolts fully.
! Do not place wheel bolts in sand or on a
dirty surface. The bolt and wheel hub
threads could otherwise be damaged when
you screw them in.
XRemove the wheel.306Flat tireBreakdown assistance

Mounting a new wheelGWARNING
Always replace wheel bolts that are damaged
or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be
repaired immediately. Do not continue to
drive under these circumstances! Contact an
authorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect wheel bolts or improperly tightened
wheel bolts can cause the wheel to come off.
This could cause an accident. Make sure to
use the correct wheel bolts.
GWARNING
Only use genuine Mercedes-Benz wheel bolts.
Other wheel bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise, the vehicle could
fall off the jack.
:Wheel bolts for 18", 19" and 20" wheels2Wheel bolts for the collapsible spare
wheel
! Always use wheel bolts ; to mount the
collapsible spare wheel. Using other wheel
bolts to mount the collapsible spare wheel
could damage the brake system.
GWARNING
Make sure to use the original length wheel
bolts when remounting the original wheel
after it has been repaired.
XClean the wheel and wheel hub contact
surfaces.
! To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt.
XSlide the emergency spare wheel onto the
alignment bolt and push it on.XTighten the wheel bolts until they are
finger-tight.XUnscrew the alignment bolt.XTighten the last wheel bolt until it is finger-
tight.XInflate the collapsible spare wheel
( Y page 307).
Inflating the collapsible spare wheel
GWARNING
Inflate the collapsible spare wheel only after
the wheel is properly attached.
Inflate the collapsible spare wheel using the
tire inflation compressor before lowering the
vehicle.
Your vehicle is equipped with one of two tire
inflation compressors:
R Version 1: tire inflation compressor with a
pressure gauge on the air hose
R Version 2: tire inflation compressor with
an integrated pressure gauge
The following description applies to both
versions. Differences in the way they are used
will be explained in detail.
Flat tire307Breakdown assistanceZ

Version 1
Version 2
XVersion 1: open flap :.XVersion 1: pull connector = and the air
hose with pressure gauge ? out of the
housing.XVersion 2: pull connector = and the air
hose out of the housing.XVersion 1: make sure that the pressure
release screw on pressure gauge ? is
closed.XRemove the cap from the valve on the
collapsible spare wheel.XScrew union nut A on the air hose onto the
valve.XMake sure on/off switch ; of the tire
inflation compressor is set to 0.XInsert plug 3 into the socket in the
footwell of the second row of seats
( Y page 268).
!
None of the other sockets or cigarette
lighters are designed for operating the tire
inflation compressor.
XMake sure that the SmartKey is in position
1 (Y page 145) in the ignition lock.XPress on/off switch ; on the tire inflation
compressor to I.
The tire inflation compressor is switched
on. The tire is inflated. Gauge ? shows the
tire pressure.
! Do not operate the tire inflation
compressor for longer than eight minutes
at a time without a break. It may otherwise
overheat.
The tire inflation compressor can be
operated again once it has cooled down.
XInflate the tire to the specified tire
pressure.
The specified tire pressure is printed on the
yellow label of the emergency spare wheel.XWhen the specified tire pressure has been
reached, press on/off switch 2 on the
electric air pump to 0.
The tire inflation compressor is switched
off.XTurn the SmartKey to position 0 in the
ignition lock.XVersion 1: if the tire pressure is higher than
the specified pressure, open the pressure
release screw on pressure gauge 4 until
the correct tire pressure has been reached.XVersion 2: if the tire pressure is higher than
the specified pressure, press pressure
release button 6 until the correct tire
pressure has been reached.XUnscrew union nut A on the air hose from
the valve.XScrew the valve cap onto the collapsible
spare wheel valve again.XVersion 1 : stow plug = and the air hose
behind flap :.XVersion 2 : stow plug = and the air hose
in the lower section of the compressor
housing.XStow the tire inflation compressor in the
designated place in the vehicle.308Flat tireBreakdown assistance

Lowering the vehicleGWARNING
Pump up the collapsible spare wheel before
lowering the vehicle. You could otherwise
damage the wheel rim.
XPlace the ratchet wrench onto the hexagon
nut of the jack so that the letters AB are
visible.XTurn the ratchet wrench until the vehicle is
once again standing firmly on the ground.XPlace the jack to one side.XTighten the wheel bolts evenly in a
crosswise pattern in the sequence
indicated ( : to A ). The tightening torque
must be 110 lb-ft (150 Nm) .GWARNING
Have the tightening torque checked
immediately after a wheel is changed. The
wheels could come loose if they are not
tightened to a torque of 110 lb/ft
(150 Nm) .
XTurn the jack back to its initial position and
store it together with the rest of the vehicle
tool kit in the cargo compartment.XTransport the defective wheel in the cargo
compartment.
or
XDepending on the size of the wheel, you
may also be able to secure the defective
wheel in the emergency spare wheel well.
In this case, you must remove the stowagetray from the emergency spare wheel well
and store it securely in the cargo
compartment.
For further information on stowing the
collapsible spare wheel, see ( Y page 298).
i When you are driving with the collapsible
spare wheel mounted, the tire pressure
loss warning system or the tire pressure
monitoring system cannot function
reliably. Only restart the tire pressure loss
warning system/tire pressure monitoring
system when the defective wheel has been
replaced with a new wheel.
Vehicles with tire pressure monitoring
system: all mounted wheels must be
equipped with functioning sensors and the
defective wheel should no longer be in the
vehicle.
MOExtended tires (tires with run-flat
properties)
MOExtended tires (tires with run-flat
properties) allow you to continue driving your
vehicle even if one or more tires are entirely
deflated.
MOExtended tires may only be used in
conjunction with the activated tire pressure
loss warning system or with the activated tire
pressure monitoring system.
The maximum permissible distance which
can be driven in run-flat mode depends on the
load in the vehicle. You can drive 50 miles
(80 km) if the vehicle is partially laden and
18 miles (30 km) if it is fully laden.
The maximum permissible distance which
can be driven in run-flat mode is counted from
the moment the tire pressure loss warning
appears in the multifunction display.
You must not exceed a maximum speed of
50 mph (80 km/h).
Flat tire309Breakdown 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
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

Notes on regularly inspecting wheels
and tiresGWARNING
Regularly check the tires for damage.
Damaged tires can cause tire inflation
pressure loss. As a result, you could lose
control of your vehicle.
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.
R Regularly check the wheels and tires of
your vehicle for damage (e.g. cuts,
punctures, tears, bulges on tires and
deformation or cracks or severe corrosion
on wheels) at least once a month, as well
as after driving off-road or on rough roads.
Damaged wheels can cause a loss of tire
pressure.
R Regularly check the tire tread depth and
the condition of the tread across the whole
width of the tire (Y page 323). If necessary,
turn the front wheels to full lock in order to
inspect the inner side of the tire surface.
R All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
mount anything onto the valve (such as tire
pressure monitoring systems) other than
the standard valve cap or other valve caps
approved by Mercedes-Benz for your
vehicle.
R Regularly check the pressure of all the tires
including the emergency spare wheel or the
spare wheel, particularly prior to long trips,
and correct the pressure as necessary
( Y page 325).
Tire tread
GWARNING
Although the applicable federal motor vehicle
safety laws consider a tire to be worn when
the tread wear indicators (TWI) become
visible at approximately 1
/ 16 in (1.6 mm), we
recommend that you do not allow your tires
to wear down to that level. As tread depth
approaches 1
/ 8 in (3 mm), the adhesion
properties on a wet road are sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Do not use tires that are excessively worn as
the tire traction on wet road surfaces
decreases significantly when the tread depth
is less than 1
/ 8 inch (3 mm).
Tread wear indicators (TWI) are required by
law. Six indicators are positioned over the tire
tread. They are visible as soon as a tread
depth of approx. 1
/ 16 inch (1.6 mm) is
reached. If this is the case, the tire is so worn
that it must be replaced.
The recommended tread depth for summer
tires is at least 1
/ 8 inch (3 mm). The
recommended tread depth for winter tires is
at least 1
/ 6 inch (4 mm).
Bar marking
: for tread wear is integrated
into the tire tread.
Notes on selecting, mounting and
replacing tires
R Only mount tires and wheels of the same
type and make.
R Only mount tires of the correct size onto
the wheels.
R After mounting new tires, run them in at
moderate speeds for the first 60 miles
Operation323Wheels and tiresZ

(100 km) as they only reach their full
performance after this distance.
R Do not use tires that are excessively worn
as the tire traction on wet road surfaces
decreases significantly when the tread
depth is less than 1
/ 8 inch (3 mm).
R Replace the tires after six years at the
latest, regardless of wear. This also applies
to the emergency spare wheel/spare
wheel.
The service life of tires depends on the
following factors amongst other things:
R driving style
R tire pressure
R mileage
MOExtended tires (tires with run-flat
properties)
MOExtended tires (tires with run-flat
properties) allow you to continue driving your
vehicle even if one or more tires are entirely
deflated.
MOExtended tires may be used only in
conjunction with the activated tire pressure
loss warning system or the activated tire
pressure monitoring system and only on
wheels specifically tested by Mercedes-Benz.
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.
You will find notes on driving with a flat tire in
the "Breakdown assistance" section
( Y page 309).
Winter operation
Please bear the following in mind
At the onset of winter, have your vehicle
winterproofed at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.
Observe the notes in the "Changing a wheel"
section ( Y page 346).
Driving with summer tires
At temperatures below 45 ‡ (+7 †), the
elasticity of summer tires and therefore also
traction and braking capability are reduced
considerably — equip your vehicle with
M+S tires. Using summer tires at very cold
temperatures could cause tears to form,
thereby damaging the tires permanently.
Mercedes-Benz cannot accept responsibility
for this type of damage.
M+S 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.
324Winter operationWheels and tires

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.
If you intend to mount snow chains, please
bear the following points in mind:
R you may not attach snow chains to all
wheel-tire combinations; see the
information under "Wheel and tire
combinations" in the "Wheels and tires"
section.
R mount snow chains only in pairs and only
to the rear wheels. Observe the
manufacturer's installation instructions.
! If snow chains are mounted on the front
wheels, the snow chains could grind
against the bodywork or components of the
chassis. This could result in damage to the
vehicle or the tires.
! Vehicles with steel wheels: if you wish
to install snow chains to steel wheels, make
sure that you remove the respective
wheels' hubcaps first. The hubcaps may
otherwise be damaged.
i You may wish to deactivate
ESP ®
(Y page 66) when pulling away with
snow chains mounted. This way you can
allow the wheels to spin in a controlled
manner, achieving an increased driving
force (cutting action).
Tire pressure
Tire pressure specifications
GWARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adversely
affect handling and fuel economy, and are
more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires can
adversely affect handling and ride comfort,
wear unevenly, increase stopping distance,
Tire pressure325Wheels and tiresZ