Page 573 of 614

vide the best possible grip in wintry road con-
ditions.
Only these tires will allow driving safety sys-
tems such as ABS and ESP
®to function opti-
mally in winter. These tires have been devel-
oped specifically for driving in snow.
Use M+S tires of the same make and tread on all wheels to maintain safe handling charac-
teristics.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
When you have mounted the M+S tires:
XCheck the tire pressures (Ypage 575).
XRestart the tire pressure monitor
(
Ypage 577).
Snow chains
GWARNING
If snow chains are installed to the front
wheels, they may drag against the vehicle
body or chassis components. This could
cause damage to the vehicle or the tires.
There is a risk of an accident.
To avoid hazardous situations:
Rnever install snow chains to the front
wheels
Ralways install snow chains in pairs to the
rear wheels.
For safety reasons, Mercedes-Benz recom-
mends 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. For more information,
please contact a qualified specialist work-
shop. If you intend to mount snow chains, please
bear the following points in mind:
RSnow chains may not be mounted on all
wheel/tire combinations. Permissible
wheel-tire combinations (
Ypage 593).
ROnly use snow chains when driving on
roads completely covered by snow.
Remove the snow chains as soon as possi-
ble when you come to a road that is not
snow-covered.
RLocal regulations may restrict the use of
snow chains. Observe the appropriate reg-
ulations if you wish to install snow chains.
RDo not exceed the maximum permissible
speed of 30 mph (50 km/h).
ROn vehicles with Active Body Control (ABC),
you must drive at a raised vehicle level if
snow chains have been installed
(
Ypage 194).
You may wish to deactivate ESP
®when pull-
ing away with snow chains installed
(
Ypage 74). You can thereby allow the wheels
to spin in a controlled manner, achieving an
increased driving force (cutting action).
Tire pressure
Tire pressure specifications
Important safety notes
GWARNING
Underinflated or overinflated tires pose the
following risks:
Rthe tires may burst, especially as the load
and vehicle speed increase.
Rthe tires may wear excessively and/or
unevenly, which may greatly impair tire
traction.
Rthe driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Tire pressure571
Wheels and tires
Z
Page 583 of 614

Permissible gross vehicle weight:the
gross weight of the vehicle, all passengers
and the load must not exceed the permissible
gross vehicle weight.
Gross Axle Weight Rating (GAWR): the
maximum permissible weight that can be car-
ried by one axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross vehi-
cle weight and maximum gross axle weight
rating), have your loaded vehicle (including
driver, occupants and the load) weighed on a
suitable vehicle weighbridge.
All about wheels and tires
Uniform Tire Quality Grading Stand-
ards
Overview of Tire Quality Grading Stand-
ards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their pur-
pose is to provide drivers with uniform relia-
ble information on tire performance data. Tire
manufacturers have to grade tires using three
performance factors: treadwear grade :,
traction grade ;and temperature grade =.
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.
Where applicable, the tire grading informa-
tion can be found on the tire sidewall between
the tread shoulder and maximum tire width. Example:
RTreadwear grade:
200
RTraction grade:AA
RTemperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
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, how-
ever, and may depart significantly from the
norm, due to variations in driving habits, ser-
vice practices and differences in road char-
acteristics and climate conditions.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction char-
acteristics.
!Avoid wheelspin. This can lead to damage
to the drive train.
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.
All about wheels and tires581
Wheels and tires
Z
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pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
Rif the vehicle has been driven for less than
1 mile (1.6 km).
Tread
The part of the tire that comes into contact
with the road.
Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kilograms (5 lbs).
These optional extras, such as high-perform-
ance brakes, level control, a roof rack or a
high-performance battery, are not included in
the curb weight and the weight of the acces-
sories.
TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identify
the purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing
capacity of a tire. Traction
Traction is the result of friction between the
tires and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are dis-
tributed over the tire tread. If the tire tread is
level with the bars, the wear limit of
áin
(1.6 mm) has been reached.
Occupant distribution
The distribution of occupants in a vehicle at
their designated seating positions.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lb) multiplied by the num-
ber of seats in the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(
Ypage 550) contains information and notes
on how to deal with a flat tire. Information on
driving with MOExtended tires in the event of
a flat tire can be found under "MOExtended
tires (tires with run-flat characteristics"
(
Ypage 551).
Rotating the wheels
GWARNING
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 acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
!On vehicles equipped with a tire pressure
monitor, electronic components are loca-
ted in the wheel.
588Changing a wheel
Wheels and tires