tire size MERCEDES-BENZ R-Class 2012 W251 Owner's Manual

Maximum load on a tire
(definition) ..................................... 345
Maximum permissible tire
pressure (definition) ....................... 344
Maximum tire load .........................337
Maximum tire load (definition) .......344
Optional equipment weight
(definition) ..................................... 345
PSI (pounds per square inch)
(definition) ..................................... 345
Replacing ....................................... 346
Service life ..................................... 323
Sidewall (definition) .......................345
Speed index (definition) .................344
Storing ........................................... 347
Structure and characteristics
(definition) ..................................... 343
Temperature .................................. 339
TIN (Tire Identification Number)
(definition) ..................................... 345
Tire bead (definition) ......................345
Tire pressure (definition) ................345
Tire pressures (recommended) ......343
Tire size (data) ............................... 347
Tire size designation, load-bearing
capacity, speed index ....................340
Tire tread ....................................... 323
Tire tread (definition) .....................345
Total load limit (definition) .............346
Traction ......................................... 338
Traction (definition) .......................345
Tread wear ..................................... 338
TWR (permissible trailer drawbar
noseweight) (definition) .................345
Uniform Tire Quality Grading
Standards ...................................... 338
Uniform Tire Quality Grading
Standards (definition) ....................343
Unladen weight (definition) ............344
Wear indicator (definition) .............346
Wheel rim (definition) ....................344
see Flat tire
Top Tether ............................................ 60
Towing Important safety guidelines ...........315
Installing the towing eye ................315
Removing the towing eye ...............316Towing a trailer
Coupling up a trailer ......................192
Decoupling a trailer .......................193
Driving tips .................................... 191
Important safety notes ..................191
Lights display message ..................222
Power supply ................................. 194
Shift range ..................................... 153
Towing away
With both axles on the ground .......316
Tow-starting
Emergency engine starting ............317
Important safety notes ..................315
Trailer
Towing ........................................... 192
Trailer loads and drawbar
noseweights ...................................... 194
Trailer towing Blind Spot Assist ............................ 191
ESP ®
................................................ 67
PARKTRONIC ................................. 186
Permissible trailer loads and
drawbar noseweights .....................194
Towing a trailer .............................. 192
Transmission
see Automatic transmission
Transporting the vehicle .................. 316
Trim pieces (cleaning instructions) . 293
Trip computer (on-board
computer) .......................................... 210
Trip meter see Trip odometer
Trip odometer
Calling up ....................................... 202
Resetting (on-board computer) ......211
Trunk
see Tailgate
Turn signals
Changing bulbs (front) ...................122
Display message ............................ 222
Switching on/off ........................... 117
see Turn signals
TWR (Tongue Weight Rating)
(definition) ......................................... 345
Type identification plate see Vehicle identification plate 18Index

U
Unlocking Emergency unlocking .......................81
From inside the vehicle (central
unlocking button) ............................. 80
V
Vanity mirror (in sun visor) .............. 265
Vehicle Correct use ...................................... 24
Data acquisition ............................... 25
Display message ............................ 234
Equipment ....................................... 21
Individual settings ..........................205
Limited Warranty ............................. 25
Loading .......................................... 333
Locking (in an emergency) ...............81
Locking (SmartKey) .......................... 73
Lowering ........................................ 309
Maintenance .................................... 22
Parking for a long period ................ 164
Pulling away ................................... 147
Raising ........................................... 305
Reporting problems .........................24
Towing away .................................. 315
Transporting .................................. 316
Unlocking (in an emergency) ...........81
Unlocking (SmartKey) ......................73
Vehicle battery
see Battery (vehicle)
Vehicle dimensions
see Technical data
Vehicle emergency locking ................ 81
Vehicle identification number see VIN
Vehicle identification plate .............. 353
Vehicle level (display message) ....... 229
Vehicle tool kit .................................. 296
Vehicle weights see Technical data
Video (DVD) ........................................ 204
Video DVD (on-board computer) ...... 204
VIN ...................................................... 353
W
Warning and indicator lamps ABS ................................................ 240
Brakes ........................................... 239
Check Engine ................................. 244
Cruise control ................................ 171
Distance warning ........................... 245
ESP ®
.............................................. 241
ESP ®
OFF ....................................... 242
Fuel tank ........................................ 244
LIM (DISTRONIC) ........................... 175
Overview .......................................... 30
Reserve fuel ................................... 244
Seat belt ........................................ 238
SRS ................................................ 243
Tire pressure monitor ....................245
Warranty ............................................ 352
Washer fluid Display message ............................ 236
see Windshield washer system
Weight
see Technical data
Wheel bolt tightening torque ........... 309
Wheel chock ...................................... 304
Wheels Changing/replacing .......................346
Changing a wheel .......................... 303
Checking ........................................ 323
Cleaning ......................................... 289
Important safety notes ..................322
Mounting a wheel .......................... 307
Removing a wheel ..........................306
Storing ........................................... 347
Tightening torque ........................... 309
Wheel size/tire size .......................347
Window curtain air bag ....................... 43
Windows Cleaning ......................................... 291
see Side windows
Windshield
Defrosting ...................................... 138
Infrared reflective .......................... 279
Windshield washer system .............. 285
Notes ............................................. 360
Windshield wipers
Problem (malfunction) ...................126
Rear window wiper ........................125Index19

GWARNING
If the BAS malfunctions, the brake system still
functions, but without the additional brake
boost available that the BAS would normally
provide in an emergency braking maneuver.
Therefore, the braking distance may increase.
ESP ®
(Electronic Stability Program)
Important safety notes
i See the "Important safety notes" section
( Y page 64).
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. If necessary, the engine output is also
modified to keep the vehicle on the desired
course within physical limits. ESP ®
assists
the driver when pulling away on wet or
slippery roads. ESP ®
can also stabilize the
vehicle during braking.
If ESP ®
intervenes, the ÷ ESP®
warning
lamp flashes in the instrument cluster.
GWARNING
Under no circumstances should you
deactivate ESP ®
when the ÷ ESP®
warning lamp in the instrument cluster
flashes. Proceed as follows:
R when driving off, apply as little throttle as
possible.
R while driving, ease up on the accelerator
pedal.
R adapt your speed to suit the prevailing road
and weather conditions.
Failure to observe these guidelines could
cause the vehicle to skid. ESP ®
cannot
prevent accidents resulting from excessive
speed.
! Only operate the vehicle for a maximum
of ten seconds on a brake test
dynamometer. Switch off the ignition.
Application of the brakes by ESP ®
may
otherwise destroy 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.
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly.
4ETS (Electronic Traction System)
i Observe the "Important safety notes"
section ( Y page 64).
Traction control is part of ESP ®
.
Traction control brakes the drive wheels
individually if they spin. This enables you to
pull away and accelerate on slippery surfaces,
for example if the road surface is slippery on
one side. In addition, more drive torque is
transferred to the wheel or wheels with
traction.
Traction control remains active if you
deactivate ESP ®
.
GWARNING
Traction control cannot reduce the risk of an
accident if you drive too fast. Traction control
cannot override the laws of physics.
Deactivating/activating ESP ®
i
Observe the "Important safety notes"
section ( Y page 64).
GWARNING
ESP ®
should not be deactivated during
normal driving other than in the
circumstances described below. Disabling
the system will reduce vehicle stability in
driving maneuvers.
Do not deactivate ESP ®
when the emergency
or spare wheel is mounted.
66Driving safety systemsSafety

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

Driving systemsProblemPossible causes/consequences and M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion. A warning tone
also sounds.GRisk of accident
The warning is issued if you approach a stationary vehicle or a
vehicle driving ahead of you at too high a speed.
XBe prepared to brake immediately.XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC (Y page 173) and the distance
warning signal ( Y page 68).
Tires
ProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 331).XIf necessary, change a wheel ( Y page 346).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is defective.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked every other week when cold and
inflated to the inflation pressure recommended by the vehicle manufacturer on the Tire and
Loading Information placard on the driver's door B-pillar or, if available, the tire inflation pressure
label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size
Warning and indicator lamps in the instrument cluster245On-board computer and displaysZ

XStop after driving for approximately ten
minutes and check the tire pressure with
the tire inflation compressor.GWARNING
If tire inflation pressure has fallen below
130 kPa (1.3 bar/26 psi) do not continue to
drive the vehicle.
Park your vehicle safely away from the
roadway and contact the nearest authorized
Mercedes-Benz Center or Roadside
Assistance.
Have the damaged tire replaced.
XCorrect the tire pressure if it is at least
130 kPa (1.3 bar/20 psi) (for the required
values, see the Tire and Loading
Information placard on the driver's side
B-pillar or the tire pressure table inside the
fuel filler flap).XTo increase the tire pressure: switch on
the tire inflation compressor.
TIREFIT kit version 1
XTo reduce the tire pressure (version 1):
open pressure release screw F on
pressure gauge G.
TIREFIT kit version 2
EPressure release buttonFPressure gaugeXTo reduce the tire pressure (version 2):
press pressure release button E on the
filler hose.XStow the tire sealant bottle and the tire
inflation compressor.XDrive to the nearest workshop and have the
tire changed there.XHave the tire sealant bottle replaced as
soon as possible at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.HEnvironmental note
Have the used tire sealant bottle disposed of
professionally, e.g. at an authorized
Mercedes-Benz Center.
XHave the tire sealant bottle replaced every
four years at a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
Changing a wheel and mounting the
spare wheel
Preparing the vehicle
GWARNING
The wheel and tire size of the emergency
spare wheel/spare wheel may differ to that of
the damaged wheel. When using an
emergency spare wheel/spare wheel the
Flat tire303Breakdown assistanceZ

handling characteristics of the vehicle may
change.
Adapt your style of driving accordingly.
Never operate the vehicle with more than one
emergency spare wheel/spare wheel that
differs in size.
Only use an emergency spare wheel/spare
wheel of a differing size briefly and do not
switch off ESP ®
.
When using an emergency spare wheel, you
must not exceed the maximum speed of
50 mph (80 km/h).GWARNING
Have the emergency spare wheel/spare
wheel replaced with a new wheel as soon as
possible at a qualified specialist workshop
which has the necessary specialist knowledge
and tools to carry out the work required.
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 Vehicles without a spare wheel/
emergency spare wheel are not equipped
with a tire-change tool kit at the factory. For
more information on which tools are
required to perform a wheel change on your
vehicle, e.g. wheel chock, lug wrench or
alignment bolt, consult an authorized
Mercedes-Benz Center.
XPrepare the vehicle as described
( Y page 299).XIf a trailer is coupled to the vehicle,
uncouple it.XRemove the following items (depending on
the vehicle's equipment) from the stowage
well under the trunk floor:
R the emergency spare wheel 35
R the wheel bolts for the emergency spare
wheel 35
R the jackRthe ratchet wrench
R the lug wrench
R the folding wheel chock
R the alignment bolt
R the tire inflation compressor 35XSecure the vehicle to prevent it from rolling
away.
Securing the vehicle to prevent it from
rolling away
GWARNING
Only jack up the vehicle on level ground or on
slight inclines/declines. The vehicle could
otherwise fall off the jack and injure you or
others.
If your vehicle is equipped with a wheel chock,
it can be found in the vehicle tool kit
( Y page 296).
The folding wheel chock is an additional
securing measure to prevent the vehicle from
rolling away, for example when changing a
wheel.
XFold both plates upwards :.XFold out lower plate ;.XGuide the lugs on the lower plate fully into
the openings in base plate =.35
Vehicles with an emergency spare wheel.304Flat 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