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. Oth-
erwise, the tires, particularly the sidewalls,
may be damaged.
Regular checking of wheels and tires
GWARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control ofyour vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
Regularly check the wheels and tires of your
vehicle for damage 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. Pay particular attention to dam-
age such as:
R cuts in the tires
R punctures
R tears in the tires
R bulges on tires
R deformation or severe corrosion on wheels
Regularly check the tire tread depth and the
condition of the tread across the whole width of the tire ( Ypage 303). If necessary, turn the
front wheels to full lock in order to inspect the
inner side of the tire surface.
All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
mount anything onto the valve other than the standard valve cap or other valve caps
approved by Mercedes-Benz for your vehicle.
Do not use any other valve caps or systems,
e.g. tire pressure monitoring systems.
Regularly check the pressure of all the tires
particularly prior to long trips. Adjust the tire
pressure as necessary ( Ypage 305).
Observe the notes on the emergency spare
wheel ( Ypage 329). The service life of tires depends, among other
things, on the following factors:
R Driving style
R Tire pressure
R Distance covered
Notes on tire tread
GWARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk
of hydroplaning increases, in particular where speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R Summer tires: âin (3 mm)
R M+S tires: ãin (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached.
Marking :shows where the bar indicator
(arrow) for tread wear is integrated into the
tire tread.
Treadwear indicators (TWI) are required by
law. Six indicators are positioned on the tire
tread. They are visible once a tread depth of
Operation303
Wheels and tires
Z
approximatelyáin(1.6 mm) has been
re ached. If this is the case, the tire is so worn
that it must be replaced.
Selecting, mounting and replacing
tires
R Only mount tires and wheels of the same
type and make.
Exception: it is permissible to install a dif-
ferent type or make in the event of a flat
tire. Observe here the "MOExtended tires
(tires with run-flat characteristics)" section
( Y page 285).
R Only mount tires of the correct size onto
the wheels.
R Break in new tires at moderate speeds for
the first 60 miles (100 km). They only reach
their full performance after this distance.
R Do not drive with tires which have too little
tread depth, as this significantly reduces
the traction on wet roads (hydroplaning).
R Replace the tires after six years at the lat-
est, regardless of wear.
Observe the notes on the emergency spare
wheel ( Ypage 329).
MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tires.
MOExtended tires may only be used in con-
junction with an active tire pressure loss
warning system and only on wheels specifi-
cally tested by Mercedes-Benz.
Notes on driving with MOExtended tires with
a flat tire ( Ypage 285).
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory.
It is therefore recommended that you addi-
tionally 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 may
be obtained from a qualified specialist work-
shop.
Winter operation
General notes
Have your vehicle winter-proofed at a quali-
fied specialist workshop at the onset of win-
ter.
Observe the notes in the "Changing a wheel" section ( Ypage 322).
Driving with summer tires
At temperatures below 45 ‡(+7 †), summer
tires lose elasticity and therefore traction and braking power. Change the tires on your vehi-cle to M+S tires. Using summer tires at very
cold temperatures could cause cracks to
form, thereby damaging the tires perma-
nently. Mercedes-Benz cannot accept
responsibility for this type of damage.
GWARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control ofyour vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
M+S tires
GWARNING
M+S tires with a tire tread depth of less than ã in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There is
a risk of an accident.
M+S tires with a tread depth of less than ãin
(4 mm) must be replaced immediately.
At temperatures below 45 ‡(+7 †), use win-
ter tires or all-season tires. Both types of tire are identified by the M+S marking.
304Winter operation
Wheels and tires
Only winter tires bearing theisnowflake
symbol in addition to the M+S marking pro-
vide the best possible grip in wintry road con- ditions. Only these tires will allow driving
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 charac- teristics.
Always observe the maximum permissible
speed specified for the M+S tires you havemounted.
When you have mounted the M+S tires:
X Check the tire pressures ( Ypage 305).
X Restart the tire pressure loss warning sys-
tem (Canada). ( Ypage 309)
Information about driving with an emergency spare wheel ( Ypage 329).
Snow chains
GWARNING
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 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:
R Snow chains may not be mounted on all
wheel/tire combinations. Permissible
wheel-tire combinations ( Ypage 326).
R Only 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 notsnow-covered.
R Local regulations may restrict the use of
snow chains. Observe the appropriate reg-
ulations 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 ( Ypage 175).
You may wish to deactivate ESP ®
when pull-
ing away with snow chains installed( Y page 64). You can thereby allow the wheels
to spin in a controlled manner, achieving an
increased driving force (cutting action).
Information about driving with an emergency spare wheel ( Ypage 329).
Tire pressure
Tire pressure specifications
Important safety notes
GWARNING
Underinflated or overinflated tires pose the
following risks: R the tires may burst, especially as the load
and vehicle speed increase.
R the tires may wear excessively and/or
unevenly, which may greatly impair tiretraction.
R the driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Tire pressure305
Wheels and tires
Z
Example:
R Treadwear grade: 200
R Traction grade: AA
R Temperature 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.
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 wet pavement 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 surfa-
ces.
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Mercedes-Benz recommends a minimum
tread depth of ãin (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth ( Ypage 303). Winter tires can
reduce the braking distance on snow-covered surfaces in comparison with summer tires.
The braking distance is still much further thanon surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) ( Ypage 304).
Temperature
GWARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, 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, representing the tire's resistance to
the generation of heat and its ability to dissi- pate heat when tested under controlled con-
ditions 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.
All about wheels and tires315
Wheels and tires
Z
Curb weight
The weight of a vehicle with standard equip-
ment including the maximum capacity of fuel,oil and coolant. It also includes the air-condi-
tioning 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 is the maximum
permissible weight in kilograms or lbs 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 axleby two.
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the tire's
surface. The tire pressure is specified in
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:
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) 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 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the accesso-
ries.
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.
All about wheels and tires321
Wheels and tires
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