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.
The tire pressure monitor will not warn you of: R an incorrectly set tire pressure
R sudden loss of tire pressure, for example
caused through intrusion from a foreign
object G
WARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded
and malfunction, which can cause tire pres-
sure 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. !
The pressure difference between tires on
any one axle must be no greater than
10 kPa
(0.1 bar/1.5 psi).
i The specifications shown on the sample
Tire and Loading Information placard and
tire pressure table are examples. Tire pres-
sure data are vehicle-specific and may devi-
ate from the data illustrated here. The tire
pressure specifications that are valid for
your vehicle can be found on the Tire and
Loading Information placard and the tire
pressure table on the vehicle. H
Environmental note
Check the tire pressure regularly, at least
every
14 days.
General notes You will find information on tire pressure for
the vehicle's factory-mounted tires on the
plates described here.
The recommended tire pressure for various
operating conditions can be found on the Tire
and Loading Information placard on the B-pillar
on the driver's side of the vehicle or on the tire
pressure table inside the fuel filler flap.
Further information on tire pressure can be
obtained at a qualified specialist workshop.
Tire and Loading Information placard Example: Tire and Loading Information placard
The Tire and Loading Information placard is on
the B-pillar on the driver's side of the vehicle.
The Tire and Loading Information placard con-
tains recommended tire pressures : for cold
tires. Recommended tire pressures : are
valid for the maximum permissible load and up 282
Tire pressure
Wheels and tires
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, con-
tact a qualified specialist workshop.
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 monitor, 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-
sure when the tires are cold.
The tires are cold: R if the vehicle has been parked for at least
three hours without direct sunlight on the
tires, and
R if the vehicle has not been driven further
than
1 mile (1.6 km)
Tire temperature changes depending on the
ambient temperature, driving speed and tire
load. If the tire temperature changes by 18 ‡
(10 †), the tire pressure changes by approx-
imately 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, it results in a higher value than when
the tires are cold. This is normal. Do not under
any circumstances release the air in order to
adjust the pressure to the prescribed value for
cold tires. The tire pressure would otherwise
be too low.
Observe the recommended tire pressure for
cold tires on the tire pressure table in the fuel
filler flap. Driving with tire pressure that is too high or
too low can:
R shorten the service life of the tires
R cause increased tire damage
R have a negative effect on handling charac-
teristics and thus the driving safety (e.g.
hydroplaning) Underinflated or overinflated tires
Underinflated tires: G
WARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addi-
tion, they also suffer from excessive and/or
irregular wear, which can severely impair the
braking properties and the driving character-
istics. There is a risk of an accident.
Avoid tire pressures that are too low in all
the tires, including the spare wheel.
Underinflated tires can:
R fail from being overheated
R adversely affect handling
R wear excessively and/or unevenly
R have an adverse effect on fuel consumption
Overinflated tires G
WARNING
Tires with excessively high pressure can
burst because they are damaged more eas-
ily 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 can:
R increase the braking distance
R adversely affect handling
R wear excessively and/or unevenly
R adversely affect ride comfort
R be more susceptible to damage284
Tire pressure
Wheels and tires
Maximum tire pressures
:
Maximum permitted tire pressure (exam-
ple)
Never exceed the maximum permissible tire
inflation pressure. When adjusting the tire
pressures always observe the recommended
tire pressure for your vehicle
(Y page 282).
i The actual values for tires are specific to
each vehicle and may deviate from the val-
ues in the illustration. Tire valve (snap-in valve)
Important safety notes G
WARNING
Tire valve that are not approved for your
vehicle by the distributor named on the
inside cover page may result in a loss of tire
pressure. This may affect road safety. There
is a risk of an accident.
Only use tire valve that are approved for
your vehicle by the distributor named on the
inside cover page. Always make sure you
have the correct tire valve type for the tires
on your vehicle.
! Do not screw additional weights (check
valves, etc.) onto the tire valves. The elec-
tronic components could thus be damaged.
i For safety reasons, Mercedes-Benz recom-
mends that you only use tire valves that
have been tested for use on your vehicle. Checking the tire pressure manually
In order to determine and adjust the tire pres-
sures, proceed as follows: X Remove the valve cap of the tire you wish to
check.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it with
the recommended value on the loading
information table or the tire pressure table
( Y page
282).
X If the tire pressure is too low, increase it to
the recommended value.
X If the tire pressure is too high, release air by
pressing down the metal pin in the valve.
Use 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 the steps for the other tires. Tire pressure monitor
General notes In vehicles with a tire pressure monitor sys-
tem, the vehicle's wheels have sensors instal-
led which monitor the tire pressure 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
corresponding sensors are installed on all
wheels.
Tire pressure display (only on vehicles with steer-
ing wheel buttons)
On vehicles with steering-wheel buttons, the
current pressure of the individual wheels in the
display can be shown via the Service menu. Tire pressure
285
Wheels and tires Z
For further information on displaying the cur-
rent tire pressures, refer to "Checking the tire
pressure electronically"
(Y page 287).
Important safety notes G
WARNING
Risk of accident due to incorrect tire
pressure
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommen-
ded by the vehicle manufacturer on the vehi-
cle placard or tire inflation pressure label. (If
your vehicle has tires of a different size than
the size indicated on the vehicle placard or
the tire inflation pressure label, you should
determine the proper tire inflation pressure
for those tires.)
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire to
overheat and can lead to tire failure. Under-
inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle's han-
dling and stopping ability.
Please note that the TPMS is not a substi-
tute for proper tire maintenance, and it is
the driver's responsibility to maintain cor-
rect tire pressure, even if under-inflation has
not reached the level to trigger illumination
of the TPMS low tire pressure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is combined
with the low tire pressure telltale. When the
system detects a malfunction, the telltale
will flash for approximately one minute and
then remain continuously illuminated. This sequence will continue upon subsequent
vehicle start-ups as long as the malfunction
exists.
When the malfunction indicator is illumina-
ted, the system may not be able to detect or
signal low tire pressure as intended. TPMS
malfunctions may occur for a variety of rea-
sons, including the installation of replace-
ment or alternate tires or wheels on the
vehicle that prevent the TPMS from func-
tioning properly.
Always check the TPMS malfunction telltale
after replacing one or more tires or wheels
on your vehicle to ensure that the replace-
ment 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 pres-
sure suitable for the operating conditions
(Y page
282).
Note that the correct tire pressure for the cur-
rent operating conditions must first be pro-
gramed into the tire pressure monitor. If a sub-
stantial pressure loss occurs, the warning
threshold for the warning message is aligned
to the taught-in reference values. Restart the
tire pressure monitor after adjusting the cold
tire pressure ( Y page 288). The current pres-
sures are saved as new reference values. This
will ensure that a warning message will only
appear if the tire pressure drops significantly.
The tire pressure monitor does not warn you if
a tire pressure is incorrect. Observe the notes
on the recommended tire pressure
(Y page 282).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. following
penetration by a foreign object. In this event,
brake the vehicle until it comes to a standstill.
Avoid sudden steering movements.
The tire pressure monitor has a yellow h
warning lamp in the instrument cluster for indi-
cating pressure loss/malfunctions (USA) or
pressure loss (Canada). Depending on how the
warning lamp flashes or lights up, an underin-
flated tire or a malfunction in the tire pressure
monitor is displayed:
R if the h warning lamp is lit continuously,
the tire pressure on one or more tires is sig- 286
Tire pressure
Wheels and tires
nificantly too low. The tire pressure monitor
is not malfunctioning.
R USA only: if the h warning lamp flashes
for
60 seconds and then remains lit con-
stantly, the tire pressure monitor is malfunc-
tioning.
The display also shows a message:
R on vehicles without steering wheel buttons
(Y page 207)
R on vehicles with steering wheel buttons
(Y page 224)
USA only: if the tire pressure monitor is mal-
functioning, it may be more than ten minutes
before the malfunction is shown. The h tire
pressure warning lamp flashes for 60 seconds
and then remains lit. When the malfunction
has been rectified, the h 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 meas-
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 values indi-
cated by a pressure gauge are higher than
those shown by the on-board computer. In this
case, do not reduce the tire pressures.
If radio transmitting equipment (e.g. wireless
headphones, two-way radios) is operated
inside the vehicle or in the vicinity of the vehi-
cle, this can interfere with the operation of the
tire pressure monitor.
Checking the tire pressure electroni-
cally on vehicles with steering wheel
buttons You can only check the tire pressure electroni-
cally on vehicles with steering wheel buttons.
Using the steering wheel buttons
X Turn the key to position 2 in the ignition
lock.
X Press the = or ; button to select the
Service menu.
X Use the 9 or : button to select
Tire Pressure.
X Press a to confirm.
The current tire pressure of each wheel is
shown in the display. If the vehicle has been parked for over
20 minutes
, the Tire pressure will be
displayed after driving a few minutes
message appears.
After a teach-in period, the tire pressure moni-
tor 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
Active message is shown instead of the tire
pressure display. The tire pressures are
already being monitored.
Tire pressure monitor warning mes-
sages If the tire pressure monitor detects a loss in
pressure in one or more tires, a warning mes-
sage is shown in the display. The h warn-
ing lamp lights up.
Vehicles without steering wheel buttons
R If the Correct Tire Pressure message is
shown in the display, the tire pressure in at
least one tire is too low. The tire pressure
must be corrected at the next opportunity.
R If the Check Tire Pressure Soon mes-
sage is shown in the display, the tire pres-
sure in one or more tires has dropped signif-
icantly. The tires must be checked.
R If the Warning Tire Malfunc. message is
shown in the display, the tire pressure in
one or more tires has dropped suddenly.
The tires must be checked.
Vehicles with steering wheel buttons
R If the Adjust Tire Pressure message is
shown in the display, the tire pressure in at
least one tire is too low. The tire pressure
must be corrected at the next opportunity.
R If the Check Tires message is shown in the
display, the tire pressure in one or more
tires has dropped significantly. The tires
must be checked.
R If the Warning Tire Malfunction mes-
sage is shown in the display, the tire pres-
sure in one or more tires has dropped sud-
denly. The tires must be checked. Tire pressure
287
Wheels and tires Z
Always read and follow the instructions and
safety notes related to the display messages,
which can be found in the "Tires" section.
R for vehicles without steering wheel buttons
(Y page
207)
R for vehicles with steering wheel buttons
(Y page 224)
Vehicles with steering wheel buttons: if the
wheel positions on the vehicle are rotated, the
tire pressures may be displayed for the wrong
positions for a short time. This is rectified after
a few minutes of driving; the tire pressures are
then displayed for the correct positions.
Restarting the tire pressure monitor General notes
When you restart the tire pressure monitor, all
existing warning messages are deleted and the
warning lamp goes out. The monitor uses 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 set
reference values manually as described here.
The tire pressure monitor then monitors the
new tire pressure values.
Vehicles without steering wheel buttons
The vehicle must be stationary. Use the but-
tons in the instrument cluster.
X Turn the key to position 2 in the ignition
lock.
X Using È select the Tire Pressure menu.
X Press 3 to confirm.
The display shows the Monitoring Active
message.
X Press 3 to confirm.
The display shows the Tire Pressure OK?
message.
If you wish to confirm the restart: X Press the f button.
The display shows the distance menu.
After you have driven for a few minutes, the
system checks whether the current tire pressures are within the specified range.
The new tire pressure levels are then accep-
ted as reference values and monitored.
If you wish to cancel the restart:
X Press the g button.
The display shows the tire pressure menu.
The tire pressure values stored at the last
restart will continue to be monitored.
Vehicles with steering wheel buttons Using the steering wheel buttons
X Make sure that the tire pressure of all four
wheels is set correctly for the current oper-
ating conditions. When doing so, observe
the notes under "Tire pressure"
(Y page
282).
X Turn the key to position 2 in the ignition
lock.
X Press the = or ; button to select the
Service menu.
X Select the Tire Pressure submenu with
9 or :.
X Press a to confirm.
The display shows either 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 display shows the Use Current Pres‐
sures as New Reference Values: mes-
sage.
If you wish to confirm the restart: X Press the a button.
The display shows the Tire Press. Moni‐
tor Restarted message.
After you have driven for a few minutes, the
system checks whether the current tire
pressures are within the specified range.
The new tire pressure levels are then accep-
ted 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.288
Tire pressure
Wheels and tires
Tire pressure tables
Vehicles with a gross vehicle weight of 6614 lbs (3.0 t)!
The pressure difference between tires on any one axle must be no greater than
10 kPa
(0.1 bar/1.5 psi).
The following tire pressure values apply to vehicles with: R a permissible gross weight of 6614 lbs (3.0 t)
R a gross axle weight rating of 3307 lbs(1500 kg) on the rear axle and
R the tires referred to under "Wheel/tire combinations" (Y page 302)
Always observe the notes under "Information on tire pressures" (Y page 282).
Tire pressure for the spare wheel is 350 kPa (3.5 bar/51 psi).
Partially laden vehicle Fully laden vehicle
Tire size Front axle Rear axle Front axle Rear axle
225/55 R 17 XL 280 kPa
(2.8 bar/ 41 psi) 270 kPa
(2.7 bar/ 39 psi) 310 kPa
(3.1 bar/ 45 psi) 310 kPa
(3.1 bar/ 45 psi) 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 acci-
dent.
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. Example: Tire and Loading Information placard on
the B-pillar, driver's side
Two instruction labels on your vehicle show
the maximum possible load.
(1) Tire and Loading Information placard : is
on the
B-pillar on the driver's side. Tire
and Loading Information placard :
shows the permissible number of occu-
pants and the maximum permissible load
of the vehicle. 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 per-
missible gross weight. It is made up of the
vehicle weight, all vehicle occupants, the Loading the vehicle
289
Wheels and tires Z
The markings described above are on the tire
in addition to the tire name (sales designation)
and the manufacturer's name.
i Tire data is vehicle-specific and may devi-
ate from the data in the example.
Tire size designation, load bearing
index and speed index G
WARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed
could lead to tire damage or the tire burst-
ing. 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
; Nominal aspect ration in %
= Tire code
? Rim diameter
A Load bearing index
B Speed index
Tire width: tire width : shows the nominal
tire width in millimeters.
Aspect ratio: aspect ratio ; is the size ratio
between the tire height and tire width and is
shown in percent. The aspect ratio is calcula-
ted 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.
Rim diameter: rim diameter ? is the diame-
ter 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 that 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 289).
Example:
The load-bearing index 101 indicates a maxi-
mum load of 1819 lb (825 kg) for the tire. If
two load-bearing indices are specified, the first
number specifies the load-bearing capacity for
single tires, the second the load-bearing capa-
city for twin tires. For further information on
the maximum tire load in kilograms and
pounds, see (Y page 294). For further information on the load-bearing
index, see "Load index" (Y page 294).
Speed rating: speed rating B specifies the
approved maximum speed of the tire.
Regardless of the speed index always observe
the speed limits. Drive carefully and adapt
your driving style to the traffic conditions.
i Tire data is vehicle-specific and may devi-
ate from the data in the example. Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)
S up to 112 mph (180 km/h)
T up to 118 mph (190 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
i
Not all tires that have the
M+S identifica-
tion offer the driving characteristics of win-
ter tires. In addition to the M+S marking,
winter tires also have the i snowflake
symbol on the tire wall. Tires with this mark-
ing fulfill the requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC) regard- What you should know about wheels and tires
293
Wheels and tires Z