2012 MERCEDES-BENZ B-CLASS spare tire

Observe the recommended tire pressures for
cold tires:
R
on the Tire
and Loading Information placard
on the B-pillar on the driver's side
R in the tire pressure table on the inside of
the fuel filler flap Underinflated or overinflated tires
Underinflation G
WARNING
Tires with pressure that is too low can
overheat and burst as a consequence. In
addition, they also

suffer from excessive and/
or irregular wear, which can severely impair
the braking properties and the driving
characteristics. There is a risk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
R wear quickly and unevenly
R have an adverse effect on fuel consumption
R overheat, leading to tire defects
R have an adverse effect on handling
characteristics
Overinflation G
WARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the

braking properties and the
driving characteristics. There is a risk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may:
R have an adverse effect on handling
characteristics
R wear quickly and unevenly R
be more susceptible to damage
R have an adverse effect on ride comfort
R increase the braking distance
Maximum tire pressures Never exceed the maximum permissible tire
inflation pressure. Always observe the
recommended tire pressure for your vehicle
when adjusting the tire pressure
(Y page 301).
:
Example: maximum permissible tire
pressure
i The actual values for tires are vehicle-
specific and may

deviate from the values in
the illustration. Checking the tire pressures
Important safety notes Observe the "Tire pressure information"
section (
Y page 301).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure information" section304
Tire pressure
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Tire size designation, load-bearing
capacity and speed rating
:
Tire width
; Nominal aspect ratio in %
= Tire code
? Rim diameter
A Load bearing index
B Speed rating
i Tire data is vehicle-specific and may
deviate from the data in the example.
General: depending on the manufacturer's
standards, the size imprinted in the tire wall
may not contain any letters or may contain
one letter
that
precedes the size description.
If there is no letter preceding the size
description (as shown above): these are
passenger vehicle tires according to
European manufacturing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S.
manufacturing standards.
If "LT" precedes the size description: these
are light truck tires according to U.S.
manufacturing standards.
If "T" precedes the size description: these are
compact emergency spare wheels at high tire
pressure, to be used only temporarily in an
emergency.
Tire width: tire width : shows the nominal
tire width in millimeters.
Nominal aspect ratio: aspect ratio ; is the
size ratio between the tire height and the tire
width and is shown in percent. The aspect ratio is calculated by dividing the tire width by
the tire height.
Tire code:
tire code =

specifies the tire type.
"R" represents radial tires; "D" represents
diagonal tires; "B" represents diagonal radial
tires.
Optionally, tires with a maximum speed of
over 149mph (240km/h) may have "ZR" in
the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter ? is the
diameter of the bead seat, not the diameter
of the rim flange. The rim diameter is
specified in inches (in).
Load bearing index: load bearing index A
is a numerical code which specifies the
maximum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum
permissible load can be found on the
vehicle's Tire and Loading Information
placard on the B-pillar on the driver's side
(Y page 306).
Example:
A load-bearing index of 91 indicates a
maximum load of 1,356lb (615kg) that can be
carried by the tires. For further information on
the maximum tire load in kilograms and
pounds, see (Y page 310).
For further information on the load-bearing
index, see Load index ( Y page 315).
Speed rating: speed rating B specifies the
approved maximum speed of the tire. G
WARNING
Exceeding the stated tire load-bearing
capacity and the approved maximum speed
could lead to

tire damage or the tire bursting.
There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and Tire labeling
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GAWR (Gross Axle Weight Rating)
The GAWR is
the maximum gross axle weight
rating. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side. Speed rating
The speed rating is part of the tire
identification. It specifies

the speed range for
which the tire is approved. GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants,
luggage and the drawbar noseweight, if
applicable. The gross

vehicle weight must not
exceed the gross vehicle weight rating GVWR
as specified on the vehicle identification plate
on the B-pillar on the driver's side. GVWR (Gross Vehicle Weight Rating)
The GVWR is

the maximum permissible gross
weight of a fully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight, if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side. Maximum loaded vehicle weight
The maximum weight is the sum of:
R the curb weight of the vehicle
R the weight of the accessories
R the load limit
R the weight of the factory installed optional
equipment Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa
corresponds to 1 psi. Another unit for tire
pressure is bar. 100 kilopascal (kPa) is the
equivalent of 1 bar . Load index
In addition to

the load-bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load-bearing
capacity more precisely. Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of fuel, oil

and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage. Maximum load rating
The maximum load rating in kilograms or
pounds is the maximum weight for which a
tire is approved. Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire. Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the

maximum axle load of one axle
by two. PSI (pounds per square inch)
A standard unit of measure for tire pressure. Definition of terms for tires and loading
317
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Changing a wheel
Flat tire
You can find
information on what to do in the
event of a flat tire in the "Flat tire" section
(Y page 281). You will also find information
on driving with MOExtended tires in the event
of a flat tire.
Vehicle with emergency spare wheel: in
the event of a flat tire, the emergency spare
wheel is mounted as described under
"Mounting a wheel" ( Y page 319).Rotating the wheels
G
WARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or

tires have different dimensions.
The wheel brakes or suspension components
may also be damaged. There is a risk of
accident.
Rotate front and rear wheels only if the wheels
and tires are of the same dimensions.
Always pay attention to the instructions and
safety notes when changing a wheel
(Y page 319).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires
in the center.
If your vehicle's tire configuration allows, you
can rotate the wheels according to the
intervals in the tire manufacturer's warranty
book in your vehicle documents. If no
warranty book is available, the tires should be
interchanged every 3,000 to 6,000 miles
(5,000 to 10,000 km), or earlier if tire wear
requires. Do not change the direction of
wheel rotation.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is interchanged. Check the tire pressure and, if necessary, restart the tire pressure loss
warning system.
Direction of rotation
Tires with a specified direction of rotation
have additional benefits,

e.g. if there is a risk
of hydroplaning. You will only gain these
benefits if the correct direction of rotation is
maintained.
An arrow on the sidewall of the tire indicates
its correct direction of rotation. Storing wheels
Store wheels that

are not being used in a cool,
dry and preferably dark place. Protect the
tires from oil, grease, gasoline and diesel. Cleaning the wheels
G
WARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause

invisible exterior damage
to the tires or chassis components.
Components damaged in this way may fail
unexpectedly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced
immediately. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Apply the electric parking brake manually
(Y page 150).
X Bring the front wheels into the straight-
ahead position.
X Move the DIRECT SELECT lever to position
P. Changing a wheel
319
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Tires
Summer tires Alloy wheels V1
BA
225/40 R18 92 W XL MOExtended
8, 9 7.5 J x 18 H2
Wheel offset: 2.05 in (52 mm) #
All-weather tires Alloy wheels V1
BA
225/45 R17 91 H M+SMOExtended
8, 9 7.5 J x 17 H2
Wheel offset: 2.07 in (52.5 mm
) #
Winter tires Alloy wheels V1
BA 205/50 R17 93 H XL M+S
i 6.5 J x 17 H2
Wheel offset: 1.93 in (49 mm) #
BA 205/50 R17 93 H XL
M+SiMOExtended
9 6.5 J x 17 H2
Wheel offset: 1.93 in (49 mm) #
Emergency spare wheel
Important safety notes
G
WARNING
The wheel or tire size as well as the tire type
of the spare
wheel or emergency spare wheel
and the wheel to be replaced may differ.
Mounting an emergency spare wheel may
severely impair the driving characteristics.
There is a risk of an accident.
To avoid hazardous situations:
R adapt your driving style accordingly and
drive carefully.
R never mount more than one spare wheel or
emergency spare wheel that differs in size.
R only use a spare wheel or emergency spare
wheel of a different size briefly.
R do not switch ESP ®
off.
R have a spare wheel or emergency spare
wheel of a different size replaced at the
nearest qualified specialist workshop. Observe that the wheel and tire dimensions
as well as the tire type must be correct.
When using an emergency spare wheel or
spare wheel of a different size, you must not
exceed the maximum speed of 50 mph
(80 km/h).
Snow chains must not be mounted on
emergency spare wheels. General notes
You should regularly check the pressure of
the emergency spare

wheel, particularly prior
to long trips, and correct the pressure as
necessary ( Y page 301). The value on the
wheel or as given in the "Technical data"
section ( Y page 323) is valid.
i When you are driving with the emergency
spare wheel mounted, the tire pressure
loss warning system cannot function
reliably. Only restart the tire pressure loss
8 Use of snow chains is not permitted. Observe the notes in the "Snow chains" section.
9 MOExtended tires (tires with run-flat characteristics) only in conjunction with activated tire pressure loss
warning. Emergency spare wheel
325
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warning system when the defective wheel
has been replaced with a new wheel.
An emergency spare wheel may also be
mounted against the direction of rotation.
Observe the time
restriction on use as well as
the speed limitation specified on the
emergency spare wheel.
Replace the tires after six years at the latest,
regardless of wear. This also applies to the
emergency spare wheel. Removing the emergency spare wheel
X
Open the tailgate.
X Loosen lashing straps ; on emergency
spare wheel bag :.
X Remove emergency spare wheel bag :
with the "Minispare" emergency spare
wheel.
For further information on changing and
mounting a wheel, see (
Y page 319). Technical data
"Minispare"
emergency spare
wheel
Tires Steel wheel
T 125/80 R17 99 M
Tire pressure: 420 kPa
(4.2 bar/61 psi) 3.5 B x 17 H2
ET 19.5326
Emergency spare wheel
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