Tire pressure
Tire pressure specifications
Important safety notes G
WARNING
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
steering 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
including 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.
i The
specifications on the sample Tire and
Loading Information placard and tire
pressure 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 pressure 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
The Tire and Loading Information placard is
on the B-pillar on the driver's side
(Y page 328).
The Tire and Loading Information placard
contains
the recommended tire pressures for
cold tires. The recommended tire pressures
are valid for the maximum permissible load
and up to the maximum permissible vehicle
speed.
Tire pressure table Example: tire pressure table for all tires permitted
for this vehicle by the factory
The
tire pressure table is on the inside of the
fuel filler flap.
The tire pressure table contains the
recommended pressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions. 322
Tire pressure
Wheels and tires
Example: tire pressure table with tire dimensions
If
a tire size precedes a tire pressure, the tire
pressure information following is only valid
for that tire size. The load conditions "partially
laden" and "fully laden" are defined in the
table for different numbers of occupants and
amounts of luggage. The actual number of
seats may differ. Some tire pressure tables only show the rim
diameter instead of the complete tire size,
e.g. R16. The rim diameter is part of the tire
size and can be found on the tire sidewall
(Y page 334).
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. On vehicles equipped with
the electronic tire pressure monitoring
system, 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
dependent on the driving speed and the load.
Therefore, you should only correct tire
pressures when the tires are cold. Tire pressure
323
Wheels and tires Z
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
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.
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 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 overheat, leading to tire defects
R have an adverse effect on handling
characteristics
R wear quickly and unevenly
R have
an adverse effect on fuel consumption
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 increase the braking distance
R have an adverse effect on handling
characteristics
R wear quickly and unevenly
R have an adverse effect on ride comfort
R be more susceptible to damage
Maximum tire pressures :
Example: maximum permissible tire
pressure324
Tire pressure
Wheels and tires
Never exceed the maximum permissible tire
inflation pressure. Always observe the
recommended tire pressure for your vehicle
when adjusting the tire pressure
(Y page 338).
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 notes on tire pressure
(Y page 322).
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
(Y page 322)
R on the tire pressure label on the fuel filler
flap ( Y page 322)
R in the "Tire pressure information" section
R in the "Tire pressure information" section
(Y page 322)
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
(Y page 322).
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 G
WARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure
recommended 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
Information 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 monitoring
system (TPMS) that illuminates a low tire
pressure 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 underinflated 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 stopping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the
driver's responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate if the
system is not operating properly. The TPMS Tire pressure
325
Wheels and tires
Z
malfunction indicator is combined with the
low tire pressure telltale. When the system
detects a malfunction, the warning lamp will
flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the
vehicle is started as long as the malfunction
exists.
When
the malfunction indicator is illuminated,
the system may not be able to detect or signal
low tire pressure as intended. TPMS
malfunctions may occur for a variety of
reasons, including the installation of
incompatible replacement or alternate tires
or wheels on the vehicle that prevent the
TPMS from functioning properly. Always
check the TPMS malfunction telltale after
replacing one or more tires or wheels on your
vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS to
continue to function properly.
It is the driver's responsibility to set the tire
pressure to the recommended cold tire
pressure suitable for the operating situation
(Y page 322). Note that the correct tire
pressure for the current operating situation
must first be taught-in to the tire pressure
monitor. If there is a substantial loss of
pressure, the warning threshold for the
warning message is aligned to the reference
values taught-in. Restart the tire pressure
monitor after adjusting to the cold tire
pressure ( Y page 327). The current
pressures are saved as new reference values.
As a result, a warning message will appear if
the tire pressure drops significantly.
The tire pressure monitor does not warn you
of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
(Y page 322).
The tire pressure monitor 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. If a tire pressure monitor system is installed,
the vehicle's wheels have sensors installed
that
monitor the tire pressures in all four tires.
The tire pressure monitor warns you if the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct wheel electronics units are installed
on each wheel.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss/malfunctions (USA)
or pressure loss (Canada). Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
R USA only: if the warning lamp flashes for
around a minute and then remains lit
constantly, the tire pressure monitor is
malfunctioning.
Information on tire pressures is displayed in
the multifunction display. After a few minutes
of driving, the current tire pressure of each
tire is shown in the multifunction display.
USA only: if there is a malfunction with the
tire pressure monitor it can take more than
ten minutes until the malfunction is shown by
the tire pressure warning lamp flashing for
approximately one minute and then lighting
up continuously. When the malfunction has
been rectified, the tire pressure warning lamp
goes out after a few minutes of driving.
The tire pressure values indicated by the on-
board computer may differ from those
measured 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
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the tire
pressures. 326
Tire pressure
Wheels and tires
The operation of the tire pressure monitor can
be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
i
USA only:
This device complies with part
15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause interference,
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.
i Canada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Checking tire pressure electronically X
Make sure that the SmartKey is in
position 2 (Y
page 139) in the ignition lock.
X Press the = or ; button on the
steering wheel to select the Serv. menu.
X Press the 9 or : button to select
Tire Pressure.
X Press button a.
The
current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle has been parked for over
20 minutes, the message Tire pressure will be displayed after driving a
few minutes appears.
After a teach-in period, the tire pressure
monitor
automatically recognizes new wheels
or new sensors. As long as a clear allocation
of the tire pressure values to the individual
wheels is not possible, the Tire Pressure
Monitor Active display message is shown
instead of the tire pressure display. The tire
pressures are already being monitored.
i If 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. If this occurs, note that the value
displayed for the position where the spare
wheel is mounted is not the same as the
spare wheel's current tire pressure.
Tire pressure monitor warning
messages If the tire pressure monitor detects a
significant
pressure loss on one or more tires,
a warning message is shown in the
multifunction 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
display.
X If the Correct Tire PressureCorrect
Tire Pressure message appears in the
multifunction display, check the tire
pressure
on all four wheels and correct it if
necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
short time. This is rectified after a few
minutes of driving, and the tire pressures
are displayed for the correct positions.
Restarting the tire pressure monitor When you restart the tire pressure monitor,
all
existing warning messages are deleted and
the warning lamps go out. The monitor uses Tire pressure
327
Wheels and tires Z
the currently set tire pressures as the
reference values for monitoring. In most
cases, the tire pressure monitor will
automatically detect the new reference
values after you have changed the tire
pressure. However, you can also define
reference
values manually as described here.
X Set the tire pressure to the value
recommended for the corresponding
driving situation on the Tire and Loading
Information placard on the driver's side
B-pillar ( Y page 322).
Additional
tire pressure values for different
loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(Y page 322).
X Make sure that the tire pressure is correct
on all four wheels.
X Make sure that the SmartKey is in
position 2 (Y
page 139) in the ignition lock.
X Press the = or ; button on the
steering wheel to select the Serv. menu.
X Press the 9 or : button to select
Tire Pressure.
X Press the a button.
The multifunction display shows the
current
tire pressure for the individual tires
or the Tire pressure will be
displayed after driving a few
minutes message.
X Press the : button.
The Use Current Pressures as New
Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
X Press the a button.
The Tire Press. Monitor Restarted
message appears in the multifunction
display.
After
driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored. If you wish to cancel the restart:
X
Press the % 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 up328
Loading the vehicle
Wheels and tires
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
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
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.
i The 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 test track 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. !
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.
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
freezing point.
Mercedes-Benz recommends a minimum
tread depth of ã in (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (Y page 319). Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
The braking distance is still much further than
on surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (Y page 320). 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 Uniform Tire Quality Grading Standards
333
Wheels and tires Z