2005 MERCEDES-BENZ CL55AMG flat tire

294 OperationTires and wheelsChecking 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 292). 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 137).
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.

295 Operation
Tires 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 137).

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 137).
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.

296 OperationTires 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.

297 Operation
Tires and wheels
Reactivating 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 134).
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 295).
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

298 OperationTires and wheelsIf 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.

299 Operation
Tires and wheels
Tire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
Following are some explanations for the
markings on your vehicle's tires:1Uniform Quality Grading Standards
(
page 306)
2DOT, Tire Identification Number (TIN)
(page 304)
3Maximum tire load (
page 305)
4Maximum tire inflation pressure
(
page 306)
5Manufacturer
6Tire ply material (
page 308)
7Tire size designation, load and speed
rating (
page 299)
8Load identification (
page 303)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed rating
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
For more information, see “Rims and
Tires” (
page 404).
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.

306 OperationTires and wheelsMaximum tire inflation pressure
1Maximum permissible tire inflation
pressure
This is the maximum permissible tire
inflation pressure for the tire.Always follow the recommended tire
inflation pressure (
page 292) for proper
tire inflation. Uniform Tire Quality Grading Standards
(U.S. vehicles)
Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.
1Treadwear
2Traction
3Temperature resistance
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
Warning!
G
Never exceed the max. tire inflation
pressure. Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and / or unevenly, adverse-
ly 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 com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.

308 OperationTires and wheelsTemperature
The temperature grades are A (the high-
est), B, and C, representing the tire’s resis-
tance 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 tem-
perature can cause the material of the tire
to degenerate and reduce tire life, and ex-
cessive temperature can lead to sudden
tire failure. The grade C corresponds to a
level of performance which all passenger
car tires must meet under the Federal Mo-
tor 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 ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.
Warning!
G
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underin-
flation, or excessive loading, either sepa-
rately or in combination, can cause
excessive heat build-up and possible tire
failure.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.