2012 MERCEDES-BENZ B-CLASS warning

safety systems such as ABS and ESP
®
to
function optimally in
winter. These tires have
been developed specifically for driving in
snow.
Use M+S tires of the same make and tread on
all wheels to maintain safe handling
characteristics.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
Once the winter tires are mounted:
X Check the tire pressures (Y page 305).
X Restart the tire pressure loss warning
system (Y page 305).
For more information on driving with the
emergency spare wheel, see ( Y page 325).Snow chains
G
WARNING
If snow chains are mounted on the rear
wheels, the snow

chains could cause abrasion
to the vehicle body or to chassis components.
This could cause damage to the vehicle or the
tires. There is a risk of an accident.
To avoid hazardous situations:
R never mount snow chains on the rear
wheels
R only mount snow chains in pairs on the
front wheels.
! On some tire sizes there is not enough
space for snow chains. To avoid damage to
the vehicle or tires, observe the "Wheel and
tire combinations" section under "Tires and
wheels".
For safety reasons, Mercedes-Benz
recommends that you only use snow chains
that have been specially approved for your
vehicle by Mercedes-Benz, or are of a
corresponding standard of quality. If you intend to mount snow chains, please
bear the following points in mind:
R
Snow chains may not be mounted on all
wheel/tire combinations. Permissible
wheel-tire combinations (Y page 323).
R Only use snow chains when driving on
roads completely covered by snow.
Remove the snow chains as soon as
possible when you come to a road that is
not snow-covered.
R Local regulations may restrict the use of
snow chains. Observe the appropriate
regulations if you wish to mount snow
chains.
R Do not exceed the maximum permissible
speed of 30 mph (50 km/h).
R When snow chains

are installed, never use
Active Parking Assist (Y page 172).
i You may wish to deactivate
ESP ®
(Y page 62) when pulling away with
snow chains installed. You can thereby
allow the wheels to spin in a controlled
manner, achieving an increased driving
force (cutting action).
For more information on driving with the
emergency spare wheel, see ( Y page 325). Tire pressure
Tire pressure specifications
G
WARNING
Tires with tire pressures that are too low or
too high are associated with the following
hazards:
R they can burst,

in particular if the vehicle is
heavily laden or when driven at high
speeds.
R the tires can wear excessively and/or
unevenly, which can severely impair tire
traction.
R the driving, steering and braking
characteristics may be severely impaired.
There is a risk of accident. Tire pressure
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can be found on the tire sidewall
(Y page 313).
If the tire pressures have been set to the
lower values for lighter loads and/or lower
road speeds, the pressures should be reset
to the higher values:
R
if you want to drive with an increased load
and/or
R if you want to drive at higher road speeds.
i The tire pressures for increased loads
and/or higher road speeds, shown in the
tire pressure table, may have a negative
effect on driving comfort.
If the tire pressure is not set correctly, this
can lead to
an excessive build up of heat and
a sudden loss of pressure.
For more information, contact a qualified
specialist workshop. Important notes on tire pressure
G
WARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident.
R Check the tire for foreign objects.
R Check whether the

wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage,
contact a qualified specialist workshop. G
WARNING
If you fit unsuitable accessories onto tire
valves, the tire

valves may be overloaded and
malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire
pressure monitors keep the tire valve open.
This can also result in tire pressure loss. There
is a risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the
tire pressure. The outer appearance of a tire
does not permit any reliable conclusion about
the tire pressure.
The tire temperature and pressure increase
when the vehicle is in motion. This is
dependent on the driving speed and the load.
Therefore, you should only correct tire
pressures when the tires are cold.
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has not been driven further
than 1 mile (1.6 km)
The tire temperature changes depending on
the outside temperature, the vehicle speed
and the tire load. If the tire temperature
changes by 18 ‡ (10 †), the tire pressure
changes by approximately 10 kPa (0.1 bar/
1.5 psi). Take this into account when
checking the pressure of warm tires. Only
correct the tire pressure if it is too low for the
current operating conditions. If you check the
tire pressure when the tires are warm, the
resulting value will be higher than if the tires
were cold. This is normal. Do not reduce the
tire pressure to the value specified for cold
tires. The tire pressure would otherwise be
too low. Tire pressure
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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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Checking tire pressures manually
To determine and set the correct tire
pressure, proceed as follows:
X
Remove the valve cap of the tire that is to
be checked.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the
driver's side of your vehicle.
X If necessary, increase the tire pressure to
the recommended value ( Y page 301).
X If the tire pressure is too high, release air
by pressing down

the metal pin in the valve
using the tip of a pen, for example. Then,
check the tire pressure again using the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure loss warning system
Important safety notes While the vehicle is in motion, the tire
pressure loss warning system monitors the
set
tire
pressure

using the rotational speed of
the wheels. This enables the system to detect
significant pressure loss in a tire. 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 multifunction
display.
The tire pressure warning system does not
warn you of an incorrectly set tire pressure.
Observe the notes on the recommended tire
pressure ( Y page 301).
The tire pressure loss warning system does
not replace the need to regularly check your
vehicle's tire pressures, since an even loss of
pressure on several tires at the same time
cannot be detected by the tire pressure loss
warning system. The tire pressure loss warning system is not
able to
warn

you of a sudden loss of pressure,
e.g. if the tire is penetrated by a foreign
object. In the event of a sudden loss of
pressure, bring the vehicle to a halt by braking
carefully. Avoid abrupt steering maneuvers.
The function of the tire pressure loss warning
system is limited or delayed if:
R snow chains are mounted to your vehicle's
tires.
R road conditions are wintry.
R you are driving on sand or gravel.
R you adopt a very sporty driving style
(cornering at high speeds or driving with
high rates of acceleration).
R you are driving with a heavy load (in the
vehicle or on the roof).
Restarting the tire pressure loss
warning system Restart the tire pressure loss warning system
if you have:
R
changed the tire pressure
R changed the wheels or tires
R mounted new wheels or tires
X Before restarting, make sure that the tire
pressures are set properly on all four tires
for the respective operating conditions.
The recommended tire pressures can be
found in the table on the fuel filler flap.
The tire pressure loss warning system can
only give reliable warnings if you have set
the correct tire

pressure. If an incorrect tire
pressure is set, these incorrect values will
be monitored.
X Observe the notes on tire pressure
(Y page 301).
X Make sure that the SmartKey is in
position 2 (Y page 135)

in the ignition lock. Tire pressure
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X
Press = or ; on the steering wheel
to select the Service menu.
X Press the 9 or : button to select
Tire Pressure.
X Press the a button.
The Run Flat Indicator Active
Press 'OK' to Restart message
appears in the multifunction display.
If you wish to confirm the restart:
X Press the a button.
The Tire Pressure Now OK? message
appears in the multifunction display.
X Press the 9 or : button to select
Yes.
X Press the a button.
The Run Flat Indicator Restarted
message appears in the multifunction
display.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.
or
If you wish to cancel the restart:
X Press the % button.
or
X If the Tire Pressure Now OK? message
appears, use the 9 or : button to
select Cancel.
X Press the a button.
The tire pressure values stored at the last
restart will continue to be monitored. Loading the vehicle
Instruction labels for tires and loads
G
WARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires
can also impair the
steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of your vehicle. Never overload the tires by
exceeding the maximum load.
:
B-pillar, driver's side
Two instruction labels on your vehicle show
the maximum possible load.
(1) The Tire and Loading Information placard is on the

B-pillar on the driver's side. The
Tire and Loading Information placard
shows the maximum permissible number
of occupants and the maximum
permissible vehicle load. It also contains
details of the tire sizes and
corresponding pressures for tires
mounted at the factory.
(2) The vehicle identification plate is on the B-pillar on the driver's side. The vehicle
identification plate informs you of the
gross vehicle weight

rating. It is made up
of the vehicle weight, all vehicle
occupants, the fuel and the cargo. You
can also find information about the
maximum gross axle weight rating on the
front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried
by one axle (front or rear axle). Never
exceed the maximum load or the
maximum gross axle weight rating for the
front or rear axle. 306
Loading the vehicleWheels and tires
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Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their
purpose is to provide drivers with uniform
reliable information
on
tire performance data.
Tire manufacturers have to grade tires using
three performance factors: tread wear :,
tire traction ;, and heat resistance =.
These regulations do not apply to Canada.
Nevertheless, all tires sold in North America
are provided with the corresponding quality
grading markings on the sidewall of the tire.
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
For example: Treadwear Traction Temperature
200 AA A Treadwear
The treadwear grade is a comparative rating
based on the

wear rate of the tire when tested
under controlled conditions on a specified
U.S. government course. For example, a tire
graded 150 would wear one and one-half
times as well on the government course as a
tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics and climate conditions. Traction
G
WARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test

surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum
tread depth of ã in (4 mm) for all four winter
tires ( Y page 300) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
Stopping distance, however, is still
considerably greater than when the road is Uniform Tire Quality Grading Standards
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not covered with ice or snow. Take
appropriate care when driving.
!
Avoid wheelspin. This
can lead to damage
to the drive train. Temperature
G
WARNING
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C. These represent the tire's
resistance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor
laboratory test wheel. Sustained high
temperature can cause

the material of the tire
to degenerate and reduce tire life, and
excessive temperature can lead to sudden
tire failure. The grade C corresponds to a level
of performance which all passenger car tires
must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on the
laboratory test wheel than the minimum
required by law. Tire labeling
Overview of tire labeling
The following markings are on the tire in addition
to the tire name (sales designation) and the
manufacturer's name:
:
Uniform tire Quality Grading Standard
(Y page 316)
; DOT, Tire Identification Number
(Y page 315)
= Maximum tire load ( Y page 310)
? Maximum tire pressure (Y page 304)
A Manufacturer
B Tire material ( Y page 316)
C Tire size designation, load-bearing
capacity and speed index (
Y page 313)
D Load index ( Y

page 315)
E Tire name
i Tire data is vehicle-specific and may
deviate from the data in the example. 312
Tire labeling
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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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