inflation pressure MERCEDES-BENZ G55AMG 2007 W463 Owner's Guide

294 Operation
Tires and wheels
Potential problems associated with
underinflated and overinflated tires
Underinflated tires
Underinflated tires can:

cause excessive and uneven tire wear

adversely affect fuel economy

lead to tire failure from being
overheated

adversely affect handling
characteristicsOverinflated tires
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
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:
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.

295 Operation
Tires and wheels
1Uniform Quality Grading Standards
(
page 302)
2DOT, Tire Identification Number (TIN)
(
page 299)
3Maximum tire load (
page 300)
4Maximum tire inflation pressure
(
page 301)
5Manufacturer
6Tire ply material (
page 304)
7Tire size designation, load and speed
rating (
page 295)
8Load identification (
page 298)
9Tire nameTire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed ratingGeneral:
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.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
For more information, see “Rims and tires”
(
page 416).
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

301 Operation
Tires and wheels
For more information on tire load rating
(
page 296).
For information on calculating total and
cargo load capacities (
page 282).
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 286) for proper
tire inflation.Warning!G
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard located 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.
iFor illustration purposes only. Actual data
on tires are 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,
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.

304 Operation
Tires and wheels
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.Tire 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 3 hours or
driven no more than 1 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.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

305 Operation
Tires and wheels
DOT (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
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.
GTW (G
ross Trailer Weight)
The GTW is the weight of the trailer plus
the weight of all cargo, equipment, luggage
etc. loaded on the trailer.GVW (G
ross Vehicle Weight)
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 GVW must never exceed the
GVWR indicated on the certification label
located on the driver’s door B-pillar.
GVWR (G
ross Vehicle Weight Rating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on
certification label located on the driver’s
door B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kPa to 1 psi; another metric unit for air
pressure is bars. There are 100 kilopascals
(kPa) to 1 bar.Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit, and production options
weight.
Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.

306 Operation
Tires and wheels
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, heavy duty battery,
and special trim.
PSI (P
ounds per square inch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure for
normal driving conditions is listed on the
Tire and Loading Information placard locat-
ed on the driver’s door B-pillar. Provides
best handling, tread life and riding com-
fort. If so equipped, supplemental informa-
tion pertaining to special driving situations
can be found on the tire inflation pressure
label on the inside of the fuel filler flap.Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.
TIN (Tire Identification Number)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifi-
cation mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.
Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.

308 Operation
Tires and wheels
If applicable to your vehicle’s tire confi-
guration, tires can be rotated according to
the tire manufacturer’s recommended
intervals in the tire manufacturer’s
warranty pamphlet located in your vehicle
literature portfolio. If none is available,
tires should be rotated every 3 000 to
6 000 miles (5 000 to 10 000 km), or
sooner if necessary, according to the
degree of tire wear. The same rotation
(spinning) direction must be maintained
(
page 280).
Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.For information on wheel change, see the
“Practical hints” section (page 366) and
(
page 390).
Warning!G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
97 lb-ft (130 Nm).
Only use genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.

335 Practical hints
What to do if …
ProblemPossible cause/consequenceSuggested solution
HCombination low tire
pressure/TPMS malfunction
telltale for the Advanced TPMS
illuminates continuously.The Advanced TPMS detects a loss of
pressure in at least one tire.Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers. Observe the traffic situa-
tion around you.
Read and observe messages in the
multifunction display (
page 338).
If the tire inflation pressure in the respec-
tive tire(s) has (have) been corrected, the
combination low tire pressure/TPMS
malfunction telltale goes out after few
minutes driving.
Combination low tire
pressure/TPMS malfunction
telltale for the Advanced TPMS
flashes for 60 seconds and then
stays illuminated.There is a malfunction in the Advanced
TPMS.Read and observe messages in the
multifunction display (
page 338).
Have the Advanced TPMS checked at
an authorized Mercedes-Benz Light
Truck Center.
After the malfunction has been remedied
the combination low tire pressure/TPMS
malfunction telltale goes out after few
minutes driving.

336 Practical hints
What to do if …
Warning!G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
Tire and Loading Information placard on the
driver’s door B-pillar or, if available, the tire
inflation 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 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 Advanced Tire Pres-
sure Monitoring System (Advanced TPMS)
that illuminates a low tire pressure telltale
when one or more of your tires is signifi-
cantly underinflated. Accordingly, when the
low tire pressure telltale illuminates, you
should stop and check your tires as soon as
possible, and inflate them to the proper
pressure.
Driving on a significantly underinflated tire
causes the tire to overheat and can lead to
tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the Advanced TPMS is not a sub-
stitute for proper tire maintenance, and it is
the driver’s responsibility to maintain cor-
rect tire pressure, even if underinflation has
not reached the level to trigger illumination
of the Advanced TPMS low tire pressure tell-
tale.
USA only: Your vehicle has also been
equipped with a Advanced TPMS malfunc-
tion indicator to indicate when the system is
not operating properly. The Advanced TPMS
malfunction indicator is combined with the
low tire pressure telltale. When the system
detects a malfunction, the telltale will flash
for approximately 1 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
illuminated, the system may not be able to
detect or signal low tire pressure as
intended.
Advanced TPMS malfunctions may occur for
a variety of reasons, including the installa-
tion of replacement or alternate tires or
wheels on the vehicle that prevent the Ad-
vanced TPMS from functioning properly. Al-
ways check the Advanced TPMS
malfunction telltale after replacing one or
more tires or wheels on your vehicle to en-
sure that the replacement or alternate tires
and wheels allow the Advanced TPMS to
continue to function properly.

342 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Tire pressure
displayed
only after
driving for
a few minutesThe tire inflation pressure is being checked.Drive the vehicle for a few minutes.
Tire pressure
monitor
currently
unavailableThe Advanced TPMS is unable to monitor the tire
pressure due to a nearby radio interference source.As soon as the causes for the malfunction are
no longer present, the Advanced TPMS auto-
matically becomes active again after a few
minutes driving.
Tire pressure
monitor
inoperativeThe Advanced TPMS is malfunctioning.Have the Advanced TPMS checked at an
authorized Mercedes-Benz Light Truck Center.
Have the wheel sensors installed by an autho-
rized Mercedes-Benz Light Truck Center.
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle.
You may lose control of the vehicle. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.