Checking the tire pressures
Important safety notes G
WARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adversely
affect handling and fuel economy, and are
more likely to fail from being overheated.
Do
not overinflate tires. Overinflated tires can
adversely affect handling and ride comfort,
wear unevenly, increase stopping distance,
and result in sudden deflation (blowout)
because they are more likely to become
punctured or damaged by road debris,
potholes etc.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Check the tire pressure at least once a month.
Only check and correct tire pressures when
the tires are cold ( Y page 493).
Checking tire pressure 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.
X If necessary, increase the tire pressure to
the recommended value ( Y page 493).
X If the tire pressure is too high, release air
by
pressing down the metal pin in the valve
using 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 these steps for the other tires. Tire pressure monitor
Important safety notes If a tire pressure monitor system is installed,
the vehicle's wheels have sensors that
monitor
the tire pressures in all four tires. The
tire pressure monitor warns you when 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 all wheels.
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 monitoring system 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
60 seconds and then remains lit constantly,
the tire pressure monitor is malfunctioning. 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. Tire pressure
497
Wheels and tires
Z
1. This device may not cause harmful
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 303) in the ignition lock.
X Press the = or ; button on the
steering wheel to select the Service
menu.
X Press the 9 or : button to select
Tire Pressure.
X Press the a button.
The
current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire Pressures
Displayed After Driving A Few
Minutes message appears in the display.
After a teach-in period, the tire pressure
monitor
automatically recognizes new wheels
or new sensors. If a clear allocation of the tire
pressure values 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.
i If a spare wheel/emergency 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 tire is
mounted is not the same as the spare
wheel/emergency 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 with a color.
If the Correct Tire Pressure message
appears in the multifunction display:
X 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 G
WARNING
It is the driver's responsibility to set the tire
pressure to the recommended cold tire
pressure.
Underinflated tires affect the ability
to steer or brake the vehicle. You might lose
control over the vehicle.
When you restart the tire pressure monitor,
all existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the
reference values for monitoring.
The tire pressure monitor must be restarted
when you set the tire pressure to a new value
(as a result of changed drive or load
characteristics, for example). The tire
pressure monitor then monitors the new tire
pressure values.
i Canada only: in most cases, the tire
pressure monitor recognizes the new
reference values automatically. However, Tire pressure
499
Wheels and tires Z
you can also define reference values
manually as described here.
Restart the tire pressure monitor after you
have set the tire pressure to the value
recommended for the desired driving
situation ( Y page 493). Only correct tire
pressures on cold tires. Comply with the
recommended tire pressures on the Tire and
Loading
Information placard on the B-pillar on
the driver's side. Additional tire pressure
values for driving at high speeds or with heavy
loads can be found in the tire pressure table
on the inside of the fuel filler flap.
X Make sure that the tire pressure is correct
on all four wheels.
X Make sure that the SmartKey is in position
2 in the ignition lock.
X Press the = or ; button on the
steering wheel to select the Service
menu.
X Press the 9 or : button to select
Tire Pressure.
X Press the a button.
The multifunction display shows the
current tire pressure of the individual tires
or the Tire Pressures 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 Pressure 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
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar
. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Two instruction labels on your vehicle show
the maximum possible load.
(1) The Tire and Loading Information placard 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 up
of the vehicle weight, all vehicle
occupants, the fuel and the cargo. You
can also find information about the
maximum gross axle weight rating on the
front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried
by one axle (front or rear axle). Never
exceed the maximum load or the
maximum gross axle weight rating for the
front or rear axle. 500
Loading the vehicle
Wheels and tires
Example 1 Example 2 Example 3
Step 3 Permissible cargo
and trailer load/
noseweight
(maximum gross
vehicle
weight rating
from the Tire and
Loading Information
placard minus the
gross weight of all
occupants) 1500 lbs
(680 kg) -
750
lbs (340 kg)
= 750 lbs
(340 kg) 1500 lbs
(680 kg) -
540
lbs (245 kg)
= 960 lbs
(435 kg) 1500 lbs
(680 kg) -
150
lbs (68 kg) =
1350 lbs
(612 kg) The higher the weight of all the occupants, the smaller the maximum load for luggage.
Further information can be found under "Towing a trailer"
(Y page 504). Vehicle identification plate
Even if you have calculated the total load
carefully, you should still make sure that the
gross
vehicle weight rating and the gross axle
weight rating are not exceeded. Details can
be found on the vehicle identification plate on
the B-pillar on the driver's side (Y page 500).
Gross vehicle weight: the gross weight of
the vehicle, all passengers, cargo and trailer
load/noseweight (if applicable) must not
exceed the permissible gross vehicle weight.
Gross axle weight rating: the maximum
permissible load that can be carried by one
axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross
vehicle weight and maximum gross axle
weight rating), have your loaded vehicle
(including driver, occupants, cargo, and full
trailer load if applicable) weighed on a
suitable vehicle weighbridge. Trailer load/noseweight
The
trailer load/noseweight affects the gross
weight of the vehicle. If a trailer is attached,
the trailer load/noseweight is included in the
load along with occupants and luggage. The
trailer load/noseweight is usually approximately 10% of the gross weight of the
trailer and its load.
Your Mercedes-Benz has been designed
primarily to carry passengers and their
luggage. Mercedes-Benz does not
recommend
towing a trailer with your vehicle. Maximum load rating
G
WARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar
. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure. 504
Maximum load ratingWheels and tires
in handling or steering problems, or brake
failure.
Example:
The load bearing index 91 is equivalent to a
maximum load of
1356 lbs (615 kg) that the
tire can carry. For further information on the
maximum tire load in kilograms and pounds,
see ( Y page 504).
For further information on the load bearing
index, see Load index ( Y page 509).
Speed rating: speed rating B specifies the
approved maximum speed of the tire. G
WARNING
Even when permitted by law, never operate a
vehicle at speeds greater than the maximum
speed rating of the tires.
Exceeding
the maximum speed for which tires
are rated can lead to sudden tire failure,
causing loss of vehicle control and possibly
resulting in an accident and/or serious
personal injury and possible death, for you
and for others.
Regardless of the speed rating always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions. Summer tires
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) Summer tires
Index Speed rating
ZR...Y Up to 186 mph (300 km/h)
ZR...(..Y) Above 186 mph (300 km/h)
ZR Above 149 mph (240 km/h)
R
Optionally, tires with a maximum speed of
over 149 mph (240 km/h)
may have "ZR"
in the size description depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specifications consist of load
bearing index A and speed rating B.
R If the size description of your tire includes
"ZR" and there are no service
specifications, ask the tire manufacturer in
order to find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed rating in the service specification.
Example: 245/40 ZR 18 97 Y. In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed rating
and the maximum speed of the tire is
limited to 186 mph (300 km/h).
R Every tire that has a maximum speed above
186 mph (300 km/h) must have "ZR" in the
size description and the service
specification must be given in brackets.
Example: 275/40 ZR 18 (99 Y). The speed
rating "(Y)" shows that the maximum speed
of the tire is above 186 mph (300 km/h).
Ask the tire manufacturer to find out the
maximum speed. All-weather tires and winter tires
Index Speed rating
Q M+S
29 Up to 100 mph (160 km/h)
T M+S
29 Up to 118 mph (190 km/h)
29
Or M+S i for winter tires.508
Tire labeling
Wheels and tires