tire pressure MERCEDES-BENZ G-Class 2012 W463 Owner's Guide

tires are significantly 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 vehicle's
handling and stopping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the
driver's responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the
system detects a malfunction, the telltale will
flash for approximately one minute and then
remain continuously illuminated. This
sequence will be repeated every time the
vehicle is started 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. TPMS
malfunctions may occur for a variety of
reasons, including the installation of
incompatible replacement or alternate tires
or wheels on the vehicle that prevent the
TPMS from functioning properly. Always
check the TPMS malfunction telltale after
replacing one or more tires or wheels on your
vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS to
continue to function properly.
i USA only:
If the tire pressure monitor is
malfunctioning, it may take more than
10 minutes for the tire pressure warning
lamp to inform you of the malfunction by flashing for 60 seconds and then remaining
lit.
When the malfunction has been rectified,
the tire pressure warning lamp goes out
after driving for a few minutes.
Information on tire pressures is displayed in
the multifunction
display. After a few minutes
of driving, the current tire pressure of each
tire is shown in the multifunction display.
i The tire pressure values indicated by the
on-board computer may differ from those
measured at a gas station with a pressure
gauge. The tire pressures shown by the on-
board computer refer to those measured at
sea level. At high altitudes, the tire pressure
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the
tire pressures.
i The operation of the tire pressure monitor
can be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
i USA only:
This device complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
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.
i Canada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and 250
Tire pressure
Wheels and tires

2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
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 115) in the ignition lock.
X Press and hold the V or U button on
the multifunction steering wheel until the
standard display appears in the
multifunction display ( Y page 156).
X Press and hold the & or * button
until the current tire pressure of each tire
is shown in the multifunction display.
If the vehicle has been parked for over 20
minutes, the Tire pressure displayed
only after driving for a few
minutes message appears.
i If a 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
wheel is mounted is not the same as the
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 by a red rectangle.
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,
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 245). Only correct tire
pressures on cold tires. Comply with the
recommended tire pressures on the tire and
loading information table 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 and hold the V
or U
button on
the multifunction steering wheel until the Tire pressure
251
Wheels and tires Z

standard display appears in the
multifunction display
(Y
page 156).
X Press and hold the & or * button
until the
tire pressure of each wheel or the
Tire pressure displayed only after
driving for a few minutes message
appears.
X Press the reset button on the instrument
cluster (Y page 25).
The Restart Tire Pres. Monitor?
message appears in the multifunction
display.
If you wish to confirm the restart:
X Press the W button.
The Tire Pres. 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 X 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. :
B-pillar, driver's side Maximum permissible gross vehicle
weight rating
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The maximum
permissible gross vehicle weight rating is 252
Loading the vehicle
Wheels and tires

the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified
government
test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance. G
WARNING
If ice has formed on the road, tire traction will
be substantially

reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum
tread depth of 1
/ 6 in (4 mm) for all four winter
tires ( Y page 244) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow covered
surfaces in comparison to summer tires. The
braking distance is still much further than on
surfaces that are not icy or covered with
snow. Take appropriate care when driving.
! Avoid wheelspin. This can lead to damage
to the drive train. Temperature
G
WARNING
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C, These represent the tire's
resistance 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
temperature
can

cause the material of the tire
to degenerate and reduce tire life, and
excessive 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 Motor 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 labeling
Tire labeling overview
The following markings are on the tire in
addition to the tire name (sales designation)
and the manufacturer's name: :
Uniform tire Quality Grading Standard
(Y page 257)
; DOT, Tire Identification Number
(Y page 261)
= Maximum tire load ( Y page 256)
? Maximum tire pressure (Y page 248)
A Manufacturer
B Tire material ( Y page 262)
C Tire size designation, load-bearing
capacity and speed index (
Y

page 259)258
Tire labeling
Wheels and tires

D
Load index ( Y page 261)
E Tire name
i Tire data is vehicle-specific and may
deviate from the data in the example. Tire size designation, load-bearing
capacity and speed rating
:
Tire width
; Nominal aspect ratio in %
= Tire code
? Rim diameter
A Load bearing index
B Speed rating
i Tire data is vehicle-specific and may
deviate from the data in the example.
General: depending on the manufacturer's
standards, the size imprinted in the tire wall
may not contain any letters or may contain
one letter
that precedes the size description.
If there is no letter preceding the size
description (as shown above): these are
passenger vehicle tires according to
European manufacturing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S.
manufacturing standards.
If "LT" precedes the size description: these
are light truck tires according to U.S.
manufacturing standards.
If "T" precedes the size description: these are
compact emergency spare wheels at high tire pressure, to be used only temporarily in an
emergency.
Tire width:
tire width : shows the nominal
tire width in millimeters.
Nominal aspect

ratio: aspect ratio ; is the
ratio between the tire height and tire width
and is shown as a percentage. The aspect
ratio is calculated by dividing the tire width by
the tire height.
Tire code: tire code = specifies the tire type.
"R" represents radial tires. "D" represents
diagonal tires, "B" represents diagonal radial
tires.
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).
Rim diameter: rim diameter ? is the
diameter of the bead seat, not the diameter
of the rim flange. The rim diameter is
specified in inches (in).
Load bearing index: load bearing index A
is a numerical code that specifies the
maximum load-bearing capacity of a tire. G
WARNING
The tire load rating must always be at least
half of the GAWR of your vehicle. Otherwise,
sudden tire failure may be the result which
could cause

an accident and/or serious injury
to you or others.
Always replace rims and tires with rims and
tires having the same specifications
(designation, manufacturer and type) as
shown on the original part. 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. Tire labeling
259
Wheels and tires Z

i
Not all tires that have the M+S
identification offer the driving
characteristics of winter tires. In addition
to the M+S marking, winter tires also have
the i
snowflake symbol on the tire wall.
Tires with this identification fulfill the
requirements of the Rubber Manufacturers
Association (RMA) and the Rubber
Association of Canada (RAC) regarding the
tire traction on snow and have been
especially developed for driving on snow.
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km/h).
The speed rating of tires mounted at the
factory may be higher than the maximum
speed that the electronic speed limiter
permits.
Make sure that your tires have the required
speed rating as specified in the "tires" section
(Y page 268), e.g. if you buy new tires.
Further information about reading tire data
can be obtained from any qualified specialist
workshop. Load index
i
Tire data is vehicle-specific and may
deviate from the data in the example.
In addition to the load bearing index, load
index : may be imprinted after the letters
that identify speed index B(Y page 259) on
the sidewall of the tire. R
If no
specification is given: no text (as in the
example above), represents a standard
load (SL) tire
R XL or Extra Load: represents a reinforced
tire
R Light Load: represents a light load tire
R C, D, E: represents a load range that
depends on the maximum load that the tire
can carry at a certain pressure DOT, Tire Identification Number (TIN)
U.S. tire regulations prescribe that every
manufacturer of

new tires or retreader has to
imprint a TIN in or on the sidewall of each tire
produced. The TIN is a unique identification number. The
TIN enables the tire manufacturers to inform
purchasers of recalls and other safety-
relevant matters. It makes it possible for the
purchaser to

easily identify the affected tires.
The TIN is made up of manufacturer
identification code ;, tire size =, tire type
code ? and manufacturing date A.
i Tire data is vehicle-specific and may
deviate from the data in the example.
DOT (Department of Transportation): tire
symbol : marks that the tire complies with
the requirements of the U.S. Department of
Transportation.
Manufacturer identification code:
manufacturer identification code ; provides
details on the tire manufacturer. New tires Tire labeling
261
Wheels and tires Z

have a code with two symbols. Retreaded
tires have a code with four symbols.
Further information about retreaded tires
(Y page 242).
Tire
size: identifier =
describes the tire size.
Tire type code: tire type code ? can be
used by the manufacturer as a code to
describe specific characteristics of the tire.
Date of manufacture: date of manufacture
A provides information about the age of a
tire. The first and second positions represent
the week of manufacture, starting with "01"
for the first calendar week. Positions three
and four represent the year of manufacture.
For example, a tire that is marked with
"3208", was manufactured in week 32 in
2008. Tire characteristics
i
Tire data is vehicle-specific and may
deviate from the data in the example.
This information describes the type of tire
cord and the number of layers in
sidewall : and under tire tread ;.Definition of terms for tires and
loading
Tire structure and characteristics
Describes the

number of layers or the number
of rubber-coated belts in the tread and the
sidewall of the tire. These are made of steel,
nylon, polyester and other materials. Bar
Metric unit for tire pressure.
14.5038 pounds per square inch (psi) and
100 kilopascals (kPa) are the equivalent of
1 bar. DOT (Department of Transportation)
DOT marked tires fulfill the requirements of
the United States Department of
Transportation. Average weight of the vehicle
occupants
The number of occupants for which the
vehicle is

designed multiplied by 68 kilograms
(150 lb). Uniform Tire Quality Grading
Standards
A uniform standard to grade the quality of
tires with

regards to tread quality, tire traction
and temperature characteristics. The quality
grading assessment is made by the
manufacturer following specifications from
the U.S. government. The quality grade of a
tire is imprinted on the sidewall of the tire. Recommended tire pressure
The recommended tire pressure for your
vehicle under normal driving conditions. You
will find

the recommendation on the Tire and
Loading Information placard on the B-pillar on
the driver's side of your vehicle. The
recommended tire pressure provides the best
balance between handling characteristics,
ride comfort and wear. Additional information
on particular driving conditions is located on
the tire pressure table on the inside of the fuel
filler flap. 262
Definition of terms for tires and loading
Wheels and tires

Increased vehicle weight due to
optional equipment
This is the combined weight of all standard
and optional equipment available for the
vehicle, regardless of whether it is actually
installed on the vehicle or not. Wheel rim
This is
the part of the wheel on which the tire
is mounted. GAWR (Gross Axle Weight Rating)
The GAWR

is the maximum gross axle weight
rating. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side. Speed index
The speed index is part of the tire
identification. It

specifies the speed range for
which the tire is approved. GTW (Gross Trailer Weight)
The GTW is the sum of the weight of a trailer
and the weight of the load, luggage,
accessories etc. on the trailer. GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants,
luggage and the drawbar noseweight if
applicable. The

gross vehicle weight must not
exceed the gross vehicle weight rating GVWR
as specified on the vehicle identification plate
on the B-pillar on the driver's side. GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permitted gross
weight of

the fully laden vehicle (weight of the
vehicle including all accessories, occupants,
fuel, luggage and the drawbar noseweight if
applicable). The gross vehicle weight rating is
specified on the vehicle identification plate on
the B-pillar on the driver's side. Maximum
weight of the laden vehicle
The maximum weight is the sum of the curb
weight of the vehicle, the weight of the
accessories, the maximum load and the
weight of

the optional equipment installed at
the factory. Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa is the
equivalent of 1 psi

. Another unit for tire
pressure is bar. 100 kilopascal (kPa) is the
equivalent of 1 bar. Load index
In addition

to the load bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load bearing
capacity more precisely. Curb weight
The weight of a vehicle with standard
equipment, including the maximum capacity
of fuel, oil and coolant and also includes the
air-conditioning system and optional
equipment if these are installed on the
vehicle, but does not include passengers or
luggage. Definition of terms for tires and loading
263Wheels and tires Z

Maximum tire load
The maximum tire load is the maximum
permissible weight in kilograms or lbs for
which a tire is approved. Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire. Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing
the maximum axle load of one axle
by two. PSI (pounds per square inch)
Standard unit of measurement for tire
pressure. Aspect ratio
Relationship between tire height and tire
width in percent. Tire pressure
This is pressure inside the tire applying an
outward force to every square inch of the
tire's surface.

The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold. For this,
the vehicle must have been stationary for at
least 3 hours or not have traveled more than
1.6 km (1 mile) in this time. Tire tread
The part of the tire that comes into contact
with the road. Tire bead
The tire bead ensures that the tire sits
securely on

the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim. Sidewall
The part

of the tire between the tread and the
tire bead. Weight of optional extras
The combined

weight of those optional extras
that weigh more than the replaced standard
part and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the
accessories. TIN (Tire Identification Number)
This is a unique identification number which
can be

used by a tire manufacturer to identify
tires, for example for a product recall, and
thus identify the purchasers. The TIN is made
up of the manufacturer's identity code, tire
size, tire type code and the manufacturing
date. Load bearing index
The load bearing index (also load index) is a
code that

contains the maximum load bearing
capacity of a tire. Traction
Traction is the result of friction between the
tires and the road surface. 264
Definition of terms for tires and loading
Wheels and tires

TWR (permissible trailer drawbar
noseweight)
The TWR is the maximum permissible weight
that may
act on the ball coupling of the trailer
tow hitch. Wear indicator
Narrow bars (tread wear bars) that are
distributed over

the tire tread. If the tire tread
is level with the bars, the wear limit of 1
/ 16 in
(1.6 mm) has been reached. Distribution of the vehicle occupants
Distribution of vehicle occupants over
designated seat positions in a vehicle. Maximum permissible payload
weight
Nominal load and luggage load plus
68 kilograms (150 lb) multiplied by the
number of seats in the vehicle. Changing a wheel
Flat tire
The "Roadside Assistance" section
(
Y
page

226) contains information and notes
on how to deal with a flat tire. It also provides
instructions on changing a wheel or mounting
the spare wheel. Interchanging the wheels
G
WARNING
Rotate front and rear wheels only if the tires
are of the same dimension.
If your vehicle is equipped with mixed-size
tires (different

tire dimensions front vs. rear),
tire rotation is not possible. G
WARNING
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
96 lb-ft (130 Nm).
Only use

genuine Mercedes-Benz wheel bolts
specified for your vehicle's rims.
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires
in the center.
If your vehicle's tire configuration allows, you
can rotate the wheels according to the
intervals in the tire manufacturer's warranty
book in your vehicle documents. If this is not
available, the tires should then be replaced
every 3000 to 6000 miles
(5000 to 10,000 km), or earlier if the tire wear
requires this. Do not change the direction of
wheel rotation.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is interchanged. Check the tire pressure and
reactivate the tire pressure monitor
(Y page 249) if necessary.
Information on changing a wheel and
mounting the spare wheel ( Y page 226).
! On vehicles equipped with a tire pressure
monitor, electronic components are
located in the wheel.
Tire-mounting tools should not be used
near the valve. This could damage the
electronic components.
Only have tires changed at a qualified
specialist workshop. Direction of rotation
Tires with a specified direction of rotation
have additional

benefits, e.g. if there is a risk
of hydroplaning. You will only gain these Changing a wheel
265
Wheels and tires Z