2005 MERCEDES-BENZ S CLASS inflation pressure

299 Operation
Tires and wheels
Direction of rotation
Unidirectional tires offer added advan-
tages, such as better hydroplaning perfor-
mance. To benefit, however, you must
make sure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the
intended direction of rotation (spinning) of
the tire.
Loading the vehicle
Two labels on your vehicle show how much
weight it may properly carry.

The Tire and Loading Information
placard (Example A) or the Vehicle Tire
Information placard (Example B) can be
found on the driver's door B-pillar. This
placard tells you important information
about the number of people that can be
in the vehicle and the total weight that
can be carried in the vehicle. It also
contains information on the proper size
and recommended tire inflation
pressures for the original equipment
tires on your vehicle.


The Certification label, also found on
the driver’s door B-pillar tells you about
the gross weight capacity of your vehi-
cle, called the Gross Vehicle Weight
Rating (GVWR). The GVWR includes the
weight of the vehicle, all occupants,
fuel and cargo. The Certification label
also tells you about the front and rear
axle weight capacity, called the Gross
Axle Weight Rating (GAWR). The GAWR
is the total allowable weight that can be
carried by a single axle (front or rear).
Never exceed the GVWR or GAWR for
either the front axle or rear axle.
iSpare wheels may be mounted against
the direction of rotation (spinning) even
with a unidirectional tire for temporary
use only until the regular drive wheel
has been repaired or replaced. Always
observe and follow applicable tempo-
rary use restrictions and speed limita-
tions indicated on the spare wheel.

305 Operation
Tires and wheels
Recommended tire inflation pressure
Your vehicle is equipped with either the
Tire and Loading Information placard
(Example A) or the Vehicle Tire Information
placard (Example B) located on the driver's
door B-pillar (
page 300).The tire inflation pressure should be
checked regularly and should only be ad-
justed on cold tires. The tires can be con-
sidered cold if the vehicle has been parked
for at least three hours or driven less than
one mile (1.6 km).
Follow recommended cold tire inflation
pressures listed on placard.
Keeping the tires properly inflated
provides the best handling, tread life and
riding comfort.
In addition to the tire placard on the
driver’s door B-pillar, also consult the fuel
filler flap for any additional information
pertaining to special driving situations. For
more information, see “Important notes on
tire inflation pressure” (
page 306).Placard (Example A)
1Tire and Loading Information placard
with recommended cold tire inflation
pressures
Placard (Example A) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.
Warning!
G
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 over-
heated.
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.
iData shown on placard examples is for
illustration purposes only. Tire data is
specific to each vehicle and may vary
from data shown in the illustrations
below. Refer to placard on vehicle for
actual data specific to your vehicle.

306 OperationTires and wheelsPlacard (Example B)
1Vehicle Tire Information placard with
recommended cold tire inflation
pressures
Placard (Example B) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.Important notes on tire inflation
pressure
Tire temperature and tire inflation pressure
are also increased while driving, depending
on the driving speed and the tire load.
If you will be driving your vehicle at high
speeds of 100 mph (160 km / h) or higher,
where it is legal and conditions allow,
consult the placard on the inside of the fuel
filler flap on how to adjust the cold tire in-
flation pressure. If you do not adjust the
tire inflation pressure, excessive heat can
build up and result in sudden tire failure.Be sure to readjust the tire inflation
pressure for normal driving speeds. You
should wait until the tires are cold before
adjusting the tire inflation pressure.
Some vehicles may have supplemental tire
pressure information for vehicle loads less
than the maximum loaded vehicle condi-
tion. If such information is provided, it can
be found on the placard located on the in-
side of the fuel filler flap.
Tire inflation pressure changes by approxi-
mately 1.5 psi (0.1 bar) per 18°F (10°C) of
air temperature change. Keep this in mind
when checking tire inflation pressure
where the temperature is different from
the outside temperature.
iPlacard (Example B) may list
recommended cold tire inflation
pressures for different vehicle loads.
Warning!
G
If the tire inflation pressure repeatedly
drops:

Check the tires for punctures from
foreign objects.


Check to see whether air is leaking from
the valves or from around the rim.

307 Operation
Tires and wheels
Checking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least three hours or
driven less than one mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than three hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise, the tire will be
underinflated.Checking tire inflation pressure
manually
Follow the steps below to achieve correct
tire inflation pressure:

Remove the cap from the valve on one
tire.

Firmly press a tire gauge onto the
valve.

Read tire inflation pressure on tire
gauge and check against the recom-
mended tire inflation pressure on the
placard on the driver’s door B-pillar
(page 305). If necessary, add air to
achieve the recommended tire inflation
pressure.

Install the valve cap.

Repeat this procedure for each tire.
Checking tire inflation pressure
electronically*
The tire inflation pressure monitor only
functions on wheels that are equipped with
the proper electronic sensors. It monitors
the tire inflation pressure, as selected by
the driver, in all four tires. A warning is
issued to alert you to a decrease in tire
inflation pressure in one or more of the
tires.
You can call up the tire inflation pressure
monitoring display using the control
system (
page 143).
iIf you have overfilled the tire, release
tire inflation pressure by pushing the
metal stem of the valve with e.g. a tip of
a pen. Then recheck the tire inflation
pressure with the tire gauge.

308 OperationTires and wheels
Switch on the ignition (
page 34).

Press buttonè orÿ on the mul-
tifunction steering wheel repeatedly
until the standard display menu
appears in the multifunction display
(page 143).

Press buttonj ork repeatedly
until the current tire inflation pressures
for each tire appear in the multifunc-
tion display.
iAfter you have reactivated the tire infla-
tion pressure monitor, the current tire
inflation pressures will only be shown
after a few minutes’ driving time.
During this time, you will see the follow-
ing message in the multifunction dis-
play:TIRE PRES. DISPLAY
APPEARS AFTER
DRIVING A FEW
MINUTESiPossible differences between the
readings of a tire inflation pressure
gauge of an air hose, e.g. gas station
equipment, and the vehicle’s control
system can occur. The readings issued
by the control system are more pre-
cise.
iYou can select the unit of measure
(Bar/Psi) used for the tire inflation
pressure by changing the setting in the
control system (
page 164).
Warning!
G
When the tire inflation pressure monitoring
system warning light is lit, one or more of
your tires is significantly under-inflated. You
should stop and check your tires as soon as
possible, and inflate them to the proper tire
inflation pressure as indicated on the vehi-
cle’s tire information placard. Driving on a
significantly 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 vehi-
cle’s handling and stopping ability. Each tire,
including the spare, should be checked
monthly when cold and set to the recom-
mended tire inflation pressure as specified
in the vehicle placard and owner’s manual.

309 Operation
Tires and wheels
iThe recommended tire inflation pres-
sures for your vehicle can be found on
the tire placard located on the driver’s
door B-pillar. The tire inflation pres-
sures are not listed in the owner’s man-
ual.Warning!
G
The tire inflation pressure monitor does not
indicate a warning for wrongly selected tire
inflation pressures. Always adjust tire infla-
tion pressure according to the placard on
the driver’s door B-pillar or, if available, the
inside of the fuel filler flap.
The tire inflation pressure monitor is not
able to issue a warning due to a sudden dra-
matic loss of tire inflation pressure (e.g. tire
blowout caused by a foreign object). In this
case bring the vehicle to a halt by carefully
applying the brakes and avoiding abrupt
steering maneuvers.
iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the tire inflation pressure moni-
tor to malfunction.
Warning!
G
Follow recommend tire inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the placard on the
driver’s door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout.

310 OperationTires and wheelsReactivating the tire inflation pressure
monitor
The tire inflation pressure monitor must be
reactivated in the following situations:

If you have changed the tire inflation
pressure


If you have replaced the wheels or tires


If you have installed new wheels or
tires

Using the tire placard on the driver’s
door B-pillar or, if available, the inside
of the fuel filler flap, make sure the tire
inflation pressure of all four tires is cor-
rect.

Press button j or k repeatedly
until you see the current tire inflation
pressures for each tire appear in the
multifunction display or the following
message appears in the multifunction
display:TIRE PRES. DISPLAY
APPEARS AFTER
DRIVING A FEW
MINUTES

Press the reset buttonJon the in-
strument cluster (
page 140).
The following message will appear in
the multifunction display:
MONITOR CURRENT
TIRE

PRESSURES?


Press the æ button.
The following message will appear in
the multifunction display:TIRE PRES. MONITOR
REACTIVATED The tire inflation pressure monitor will
now monitor the tire inflation pressure
values of all four tires.
The following message will appear in
the multifunction display field:TIRE PRES. DISPLAY
APPEARS AFTER
DRIVING A FEW
MINUTESThis display appears until the individual
tire inflation pressure values are
matched with the tires. The individual
values are then displayed
(page 308).
iIf you are transporting a deflated tire in
the vehicle, do not activate the tire
inflation pressure monitor until

the deflated tire is no longer in the
vehicle


you have inflated the tire to the
correct tire inflation pressure

311 Operation
Tires and wheels
If you wish to cancel activation:
Press the ç button.
If one of the following messages appears in
the multifunction display:


TIRE PRES. MONITOR
REACTIVATE AFTER
CORRECTING PRESSURE


TIRE PRESSURE

PLEASE CORRECT


Check the tire inflation pressures and
correct them if necessary.

Reactivate the tire inflation pressure
monitor.Potential problems associated with
underinflated and overinflated tires
Underinflated tire inflation pressure
Underinflated tires can:


cause excessive and uneven tire wear


adversely affect fuel economy


lead to tire failure from being
overheated


adversely affect handling
characteristicsOverinflated tire inflation pressure
Overinflated tires can:


adversely affect handling
characteristics


cause uneven tire wear


be more prone to damage from road
hazards


adversely affect ride comfort


increase stopping distance
Warning!
G
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.
Warning!
G
Follow recommended tire inflation
pressures.
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.