2012 MERCEDES-BENZ G-Class warning

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

Example 1 Example 2 Example 3
Step 3 Permissible cargo
and trailer load/
noseweight
(maximum gross
vehicle
weight
rating
from the Tire and
Loading Information
placard minus the
gross weight of all
occupants) 1500 lbs
(680 kg) -
750
lbs
(340 kg)
= 750 lbs
(340 kg) 1500 lbs
(680 kg) -
540
lbs
(245 kg)
= 960 lbs
(435 kg) 1500 lbs
(680 kg) -
150
lbs
(68 kg) =
1350 lbs
(612 kg) The higher the weight of all the occupants, the smaller the maximum load for luggage.
Further information can be found under "trailer load/noseweight"
(Y

page 256).Vehicle identification plate
Even if you have calculated the total load
carefully, you should still make sure that the
gross vehicle

weight rating and the gross axle
weight rating are not exceeded. Details can
be found on the vehicle identification plate on
the B-pillar on the driver's side of the vehicle
(Y page 252).
Gross vehicle weight: the gross weight of
the vehicle, all passengers, cargo and trailer
load/noseweight (if applicable) must not
exceed the permissible gross vehicle weight.
Gross axle weight rating: the maximum
permissible weight that can be carried by one
axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross
vehicle weight and maximum gross axle
weight rating), have your loaded vehicle
(including driver, occupants, cargo, and full
trailer load if applicable) weighed on a
suitable vehicle weighbridge. Trailer load/noseweight
The trailer
load/noseweight affects the gross
weight of the vehicle. If a trailer is attached,
the trailer load/noseweight is included in the
load along with occupants and luggage. The trailer load/noseweight is usually
approximately
10%

of the gross weight of the
trailer and its load.
Only use a trailer tow hitch that has been
approved for your vehicle by Mercedes-Benz.
Comply with the manufacturer's operating
instructions for operation, care and
maintenance. Maximum load rating
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. 256
Maximum load rating
Wheels and tires

i
The actual values for tires are vehicle-
specific and
may deviate from the values in
the illustration.
Maximum tire load : is the maximum
permissible weight for which the tire is
approved.
Further information on tire loads
(Y page 258). Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
The Uniform Tire Quality Grading Standards
are U.S. government specifications. Their
purpose is to provide drivers with uniform
reliable
information

on tire performance data.
Tire manufacturers have to grade tires using
three performance factors: tread wear :,
tire traction ;, and heat resistance =. All
tires sold in North America are provided with
the corresponding quality grading markings on the sidewall of the tire, even though these
regulations do not apply to Canada.
i
The actual values for tires are vehicle-
specific and

may deviate from the values in
the illustration.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
For example: Tread wear Traction Temperature
200 AA A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Tread wear
The tread

wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. government test track. For example, a
tire graded 150 would wear one and one-half
times as well on the government test track as
a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics and climate conditions. Traction
G
WARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent Uniform Tire Quality Grading Standards
257
Wheels and tires Z

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

Example:
The load bearing index 91 is equivalent to a
maximum load of
1356 lbs (615 kg) that the
tire can carry. For further information on the
maximum tire load in kilograms and pounds,
see ( Y
page 256).
For further information on the load bearing
index, see Load index ( Y page 261).
Speed rating: speed rating B specifies the
approved maximum speed of the tire. G
WARNING
Even when permitted by law, never operate a
vehicle at speeds greater than the maximum
speed rating of the tires.
Exceeding the

maximum speed for which tires
are rated can lead to sudden tire failure,
causing loss of vehicle control and possibly
resulting in an accident and/or serious
personal injury and possible death, for you
and for others.
Regardless of the speed rating always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions. Summer tires
Index Speed rating
Q Up to 100 mph (160 km/h)
R Up to 106 mph (170 km/h)
S Up to 112 mph (180 km/h)
T Up to 118 mph (190 km/h)
H Up to 130 mph (210 km/h)
V Up to 149 mph (240 km/h)
W Up to 168 mph (270 km/h)
Y Up to 186 mph (300 km/h)
ZR...Y Up to 186 mph (300 km/h) Summer tires
Index Speed rating
ZR...(..Y) Above 186 mph (300 km/h)
ZR Above 149 mph (240 km/h)
R
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

).
The service specification is made up of load
bearing index A and speed rating B.
R If the size description of your tire includes
"ZR" and there are no service
specifications, ask the tire manufacturer in
order to find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed rating in the service specification.
Example: 245/40 ZR 18 97 Y. In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed rating
and the maximum speed of the tire is
limited to 186 mph (300 km/h).
R Every tire that has a maximum speed above
186 mph (300 km/h) must have "ZR" in the
size description and the service
specification must be given in brackets.
Example: 275/40 ZR 18 (99 Y). The speed
rating "(Y)" shows that the maximum speed
of the tire is above 186 mph (300 km/h).
Ask the tire manufacturer to find out the
maximum speed. All-weather tires and winter tires
Index Speed rating
Q M+S
18 Up to 100 mph (160 km/h)
T M+S
18 Up to 118 mph (190 km/h)
H M+S
18 Up to 130 mph (210 km/h)
V M+S
18 Up to 149 mph (240 km/h)
18
Or M+S i for winter tires.260
Tire labeling
Wheels and tires