2005 MERCEDES-BENZ S CLASS tire pressure

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.

312 OperationTires and wheelsTire 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 319)
2DOT, Tire Identification Number (TIN)
(page 317)
3Maximum tire load (
page 318)
4Maximum tire inflation pressure
(
page 319)
5Manufacturer
6Tire ply material (
page 321)
7Tire size designation, load and speed
rating (
page 312)
8Load identification (
page 316)
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 422).
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.

313 Operation
Tires and wheels
General:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only. Tire width
The tire width1 (
page 312) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (page 312) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 312) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal or bias ply construction; letter “B”
means belted-bias ply construction.
At the tire manufacturer's option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR 18).
For additional information, see “Tire speed
rating” (
page 314).Rim diameter
The rim diameter4 (
page 312) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (page 312) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 318) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.

316 OperationTires and wheelsAll-season and winter tires
Load identification
1Load identificationIn addition to tire load rating, special load
information may be molded into the tire
sidewall following the letter designating
the tire speed rating1 (
page 316).
No specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
XL (Extra Load): designates an extra load
(or reinforced) tire.
Light Load: designates a light load tire.
C, D, E: designates load range associated
with the maximum load a tire can carry at
a specified pressure.
Index
Speed rating
QM+S
up to 100 mph (160 km/h)
TM+S
up to 118 mph (190 km/h)
HM+S
up to 130 mph (210 km/h)
VM+S
up to 149 mph (240 km/h)
iThe marking “M+S” next to the service
description designates tires with mud
and snow capabilities.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.

319 Operation
Tires and wheels
Maximum 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 305) 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.

322 OperationTires and wheelsTire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least three hours or
driven no more than one mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
Certification label located on the driver's
door B-pillar.
GVW (G
ross V
ehicle W
eight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GWV must never exceed the
GWVR indicated on the Certification label
located on the driver's door B-pillar.