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.
R 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. Damage includes bulges
and deformation on tires, cuts, punctures,
cracks or severe corrosion on wheels, for
example. Damaged wheels can cause a
loss of tire pressure.
R Regularly check the tire tread depth and
the condition of the tread across the whole
width of the tire ( Ypage 231). In order to
inspect the inner side of the tire surface,
turn the steering wheel to full lock.
R All wheels must have a valve cap to protect
the valve against dirt and moisture. Do notinstall anything onto the valve other than
the standard valve cap or a valve cap
approved by Mercedes-Benz for your vehi-
cle.
Do not install anything onto the valve, suchas tire pressure monitoring systems.
R You should regularly check the pressure of
all your tires including the spare wheel, par- ticularly prior to long trips. Adjust the tire
pressure as necessary ( Ypage 237).
The service life of tires depends, among other things, on the following factors:
R Driving style
R Tire pressure
R Distance covered
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 the tread wear indicator
(TWI). The arrow indicates the placement of
the tire tread.
Do not drive with tires which have too little
tread depth. tire traction on wet road surfaces decreases significantly when the tread depth
is less than 1
/ 8 in (3 mm).
Treadwear indicators (TWI) are required by
law. Six indicators are positioned over the tire
tread. They are visible once the tread depth is
approximately 1
/ 16 in (1.6 mm). If this is the
case, the tire is so worn that it must be
replaced.
The recommended tread depth for summer
tires is at least 1
/ 8 in (3 mm). The recommen-
ded tread depth for winter tires is at least 1
/ 6
in (4 mm).
Operation231
Wheels and tires
Z
Selecting, mounting and replacing tires
ROnly mount tires and wheels of the same
type and make.
R Only mount approved tires of the correct
size onto the wheels.
R Tires are supplied with a protective layer
from the factory. Break in new tires at mod-
erate speeds for the first 60 miles
(100 km). They only reach their full per-
formance 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. This also applies to
the spare wheel.
Winter operation
You can find information about this in the
Digital Operator's Manual.
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 tire
traction.
R the driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and check the pressure of all the tires includ-
ing the spare wheel:
R monthly, at least
R if the load changes
R before beginning a long journey
R under different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
iThe specifications on the sample Tire and
Loading Information placard and tire pres-
sure tables are examples. Tire pressure
specifications are vehicle-specific and may
deviate from the data shown here. The tire pressure specifications that are valid for
your vehicle can be found on the Tire and
Loading Information placard and tire pres-
sure table on the vehicle.
General notes
The recommended tire pressures for the tires
mounted at the factory can be found on the
labels described here.
Operation with a trailer: the applicable
value for the rear tires is the maximum tire
pressure value stated in the table inside the
fuel filler flap.
Further information on tire pressures can be
obtained at a qualified specialist workshop.
Tire and Loading Information placard
:Recommended tire pressures
232Tire pressure
Wheels and tires
the tire pressure. On vehicles equipped with
the electronic tire pressure monitoring sys-
tem, the tire pressure can be checked using
the on-board computer.
The tire temperature and pressure increase
when the vehicle is in motion. This is depend-ent on the driving speed and the load.
Therefore, you should only correct tire pres-
sures 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 been driven for less 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 check-
ing 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 result-
ing 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.
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
Observe the following for the tire pressure on the spare wheel: R the tire and loading information table on
the B-pillar on the driver's side.
R the tire pressure sticker on the inside of the
fuel filler flap.Underinflated or overinflated tires
Underinflation
GWARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition, they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak-
ing 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 overheat, leading to tire defects
R have an adverse effect on handling charac-
teristics
R wear quickly and unevenly
R have an adverse effect on fuel consumption
Overinflation
GWARNING
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 increase the braking distance
R have an adverse effect on handling charac-
teristics
R wear quickly and unevenly
R have an adverse effect on ride comfort
R be more susceptible to damage
234Tire pressure
Wheels and tires
Maximum tire pressures
:Example: maximum permissible tire pres-sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the rec-
ommended tire pressure for your vehicle
when adjusting the tire pressure( Y page 248).
iThe 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 notes on tire pressure ( Y page 232).
Information on air pressure for the tires on
your vehicle can be found:
R on the tire pressure label on the fuel fillerflap
R in the "Tire pressure data" section(Y page 232)
Checking tire pressures manually
To determine and set the correct tire pres-
sure, 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 to
the recommended value on the Tire and
Loading Information placard on fuel filler
flap of your vehicle ( Ypage 233).
X The tire pressure is too low: increase the
tire pressure to the recommended value.
X The tire pressure is too high: press down
the metal pin in the valve using the tip of a
pen, for example.
Air is released from the tire.
X Check the tire pressure again with the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires.
Tire pressure monitor
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure rec-
ommended by the vehicle manufacturer on
the Tire and Loading Information placard on
the driver's door B-pillar or the tire pressure
label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the
size indicated on the Tire and Loading Infor-
mation placard or the tire pressure label, you should determine the proper tire pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoringsystem (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale illuminates,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can lead to tire failure. Underinflation also
reduces fuel efficiency and tire tread life, and
may affect the vehicle's handling and stop-
ping ability.
Tire pressure235
Wheels and tires
Z
ured at a gas station with a pressure gauge.
The tire pressures shown by the on-board
computer refer to those measured at sea
level. At high altitudes, the tire pressure val-
ues indicated by a pressure gauge are higher
than those shown by the on-board computer. In this case, do not reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio trans-
mitting equipment (e.g. radio headphones,
two-way radios) that may be being operated
in or near the vehicle.
iUSA only:
This device complies with part 15 of the
FCC Rules. Operation is subject to the fol-
lowing two conditions:
1. This device may not cause harmful inter- ference, and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
iCanada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause harmful inter- ference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Checking the tire pressure electroni-cally
X Make sure that the SmartKey is in posi-
tion 2in the ignition lock ( Ypage 103).
X Press the =or; button on the steer-
ing wheel to select the
Serv.menu. X
Press the 9or: button to select
Tire Pressure.
X Press the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle has been parked for over
20 minutes, the
Tire pressure will be
displayed after driving a few
minutesmessage appears.
After a teach-in process, the tire pressure
monitor automatically detects new wheels or
new sensors. As long as a clear allocation of
the tire pressure value to the individual
wheels is not possible, the
Tire Pressure
Monitor Activedisplay message is shown
instead of the tire pressure display. The tire
pressures are already being monitored.
iIf a spare wheel is mounted, the system
may continue to show the tire pressure of
the wheel that has been removed for a few minutes. Observe that the displayed value
is not the same as the current tire pressure
of the emergency spare wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a signifi-
cant pressure loss on one or more tires, a
warning message is shown in the multifunc-
tion display. A warning tone also sounds and
the tire pressure warning lamp lights up in the
instrument cluster.
Each tire that is affected by a significant loss of pressure is highlighted in the pressure dis-
play.
X If the
Correct Tire Pressuremessage
appears in the multifunction display, check the tire pressure on all four wheels and cor-
rect it if necessary.
X If the
CheckTiresmessage appears in the
multifunction display, the tire pressure in
one or more tires has dropped significantly and the tires must be checked.
X If the
Tire Press. Warning Caution
Tire Malfunctionmessage appears in
Tire pressure237
Wheels and ti res
Z
which all passenger car tires must meet underthe 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
:Uniform tire Quality Grading Standard ( Y page 248)
;DOT tire Identification Number(Y page 247)
=Maximum tire load ( Ypage 246)
?Maximum tire pressures ( Ypage 235)
AManufacturer
BTire material ( Ypage 247)
CTire size designation, load-bearing capa-
city and speed rating ( Ypage 244)
DLoad identification ( Ypage 246)
ETire name
The markings described above are on the tire in addition to the tire name (sales designa-
tion) and the manufacturer's name.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city 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.
:Tire width
;Height-width ratio in percentage
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, a letter is imprinted into the tire
wall before the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description:
passenger vehicle tires according to U.S.
manufacturing standards.
If "P" precedes the size description: light
truck tires according to U.S. manufacturing
standards.
If "T" precedes the size description: these are
compact emergency spare wheels at high tire
244Tire labeling
Wheels and tires
Bar
Metric unit for tire pressure. 14.5038 poundsper square inch (psi) and 100 kilopascals
(kPa) are the equivalent of 1 bar.
DOT (Department of Transportation)
DOT-marked tires fulfill the requirements of
the U S Department of Transportation.
Normal occupant weight
The number of occupants for which the vehi-
cle is designed multiplied by 68 kilograms
(150 lbs).
Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of
tires with regards to tread quality, tire traction
and temperature characteristics. The quality
grading assessment is made by the manufac- turer following specifications from the U.S.
government. The ratings are molded into the
sidewall of the tire.
Recommended tire pressures
The recommended tire pressure applies to
the tires mounted at the factory.
The Tire and Loading Information placard con- tains the recommended tire pressures for
cold tires on a fully loaded vehicle and for the
maximum permissible vehicle speed.
The tire pressure table contains the recom-
mended pressures for cold tires for various
operating conditions, i.e. differing load and
speed conditions.
Increased vehicle weight due to
optional equipment
The combined weight of all standard and
optional equipment available for the vehicle,
regardless of whether it is actually installed
on the vehicle or not.
Rim
This is the part of the wheel on which the tire
is mounted.
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 identifica-
tion. It specifies the speed range for which the
tire is approved.
GTW (Gross Trailer Weight)
The GTW is the weight of a trailer including the weight of the load, luggage, accessories etc.
on the trailer.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants, lug-
gage and the drawbar noseweight, if applica-
ble. 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, occu-
pants, fuel, luggage and the drawbar nose-
weight, if applicable). The gross vehicle
weight rating is specified on the vehicle iden-
tification plate on the B-pillar on the driver's
side.
248Tire labeling
Wheels and tires
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 identifythe 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.
TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow hitch can support.
Treadwear indicators
Narrow bars (tread wear bars) that are dis-
tributed over the tire tread. If the tire tread islevel 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
Nominal load and luggage load plus 150 lb
(68 kilograms) multiplied by the number of
seats in the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section ( Y page 216) contains information and notes
on how to deal with a flat tire.
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.
Tire-mounting tools should not be used
near the valve. This could damage the elec- tronic components.
Only have tires changed at a qualified spe-cialist workshop.
Rotating front and rear wheels of differing
dimensions can render the general operating
permit invalid.
Always pay attention to the instructions and
safety notices in the section on "Changing a
wheel and mounting a spare wheel"( Y page 251).
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 inter-
vals in the tire manufacturer's warranty book
in your vehicle documents. If no warranty
book is available, the tires should be rotated
250Changing a wheel
Wheels and tires