2018 MERCEDES-BENZ G-CLASS Owner's Manual

Checking the tire pressures
Important safety notes
Observe the notes on tire pressure
(Ypage 260).
Information on air pressure for the tires on your
vehicle can be found:
Ron the vehicle's Tire and Loading Information
placard on the B-pillar
Rin the tire pressure table in the fuel filler flap
(Ypage 120)
Runder "Tire pressure" (Ypage 260)
Checking tire pressures manually
To determine and set the correct tire pressure,
proceed as follows:
XRemove the valve cap of the tire that is to be
checked.
XPress the tire pressure gage securely onto the
valve.
XRead the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
(
Ypage 260).
XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure monitor
General notes
If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the tire
pressures in all four tires. The tire pressure mon-
itor warns you if the pressure drops in one or
more of the tires. The tire pressure monitor only
functions if the corresponding sensors are
installed in all wheels.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each wheel
is shown in the Serv.
menu.
Information on the message display can be
found in the "Checking the tire pressure elec-
tronically" section (
Ypage 264).
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure rec-
ommended by the vehicle manufacturer on
the Tire and Loading Information placard on
the driver's door B-pillar or the tire 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 Infor-
mation placard or the tire pressure label, you
should determine the proper tire pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your 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 underin-
flated 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 stop-
ping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the driv-
er's responsibility to maintain correct tire
pressure, even if unde rinf
lation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
USA only:
Tire pressure263
Wheels and tires
Z

Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate if 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 warning lamp will
flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle 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 malfunc-
tions may occur for a variety of reasons,
including the mounting of incompatible
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from func-
tioning properly. Always check the TPMS mal-
function 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 prop-
erly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
(
Ypage 260). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If a sub-
stantial loss of pressure occurs, the warning
threshold for the warning message is aligned to
the taught-in reference values. Restart the tire
pressure monitor after adjusting the pressure of
the cold tires (
Ypage 265). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the tire pressure drops significant
ly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
(
Ypage 260).
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The tire pressure monitor has a yellow h
warning lamp on the instrument cluster for indi- cating a pressure loss or malfunction. The way
that the warning lamp flashes or lights up indi-
cates whether a tire pressure is too low or
whether the tire pressure monitor is malfunc-
tioning:
Rif the
h warning lamp is lit continuously,
the tire pressure in one or more tires is sig-
nificantly too low. The tire pressure monitor is
not malfunctioning.
Rif the h warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the hwarning lamp, a message
appears in the multifunction display. Observe
the information on display messages
(
Ypage 187).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. The
malfunction is indicated first by the htire
pressure warning lamp flashing for approx-
imately one minute and then remaining lit. If the
malfunction has been rectified, the htire
pressure warning lamp goes out after driving for
a few minutes.
The tire pressure values indicated by the on-
board computer may differ from t
hose meas-
ured 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.
The operation of the tire pressure monitor can
be affected by interference from radio transmit-
ting equipment (e.g. radio headphones, two-way
radios) that may be being operated in or near the
vehicle.
Checking the tire pressure electroni-
cally
XEnsure that the SmartKey is in position 2in
the ignition lock.
XPress the =or; button on the steering
wheel to select the Serv.menu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The multifunction display shows the current
tire pressure of each wheel.
If the vehicle has been parked for over
20 minutes, the Tire pressure will be
264Tire pressure
Wheels and tires

displayed after driving a few minutesmessage appears.
After a teach-in process, the tire pressure mon-
itor automatically detects new wheels or new
sensors. As long as a clear allocation of the tire
pressure value to the individual wheels is not
possible, theTire
PressureMonitorActivedisplay message is shown instead of the tire
pressure display. The tire pressures are already
being monitored.
If a spare wheel is installed, the system may
continue to show the tire pressure of the wheel
that has been removed for a few minutes. Please
note that in this case, the value displayed for the
replaced wheel does not indicate the current
tire pressure of the spare wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message is
shown in the multifunction display. The yellow
htire pressure warning lamp then lights up.
RIf the Correct Tire Pressuremessage
appears in the multifunction display, the tire
pressure in at least one tire is too low. The tire
pressure must be corrected when the oppor-
tunity arises.
RIf the Check Tiresmessage appears in the
multifunction display, the tire pressure in at
least one tire has dropped significantly. The
tires must be checked.
RIf the Caution - Tire Malfunc.message
appears in the multifunction display, the tire
pressure in at least one tire has dropped sud-
denly. The tires must be checked.
Be sure to observe the instructions and safety
notes in the display messages in the "Tires" sec-
tion (
Ypage 187).
If the position of the wheels on the vehicle is
changed, the tire pressure may be displayed in
the wrong positions for a short time. This is rec- tified after a few minutes of driving, and the tire
pressures are displayed for the correct posi-
tions.
Restarting the tire pressure monitor
When you restart the tire pressure monitor, all
existing warning messages are deleted and the
h warning lamp goes out. The monitor uses
the currently set tire pressures as the reference
values for monitoring. In most cases, the tire pressure monitor will automatically detect the
new reference values after you have changed
the tire pressure. However, you can also set ref-
erence values manually as described here. The
tire pressure monitor then monitors the new tire
pressure values.
XSet the tire pressure to the value recommen-ded for the corresponding driving situation on
the Tire and Loading Information placard on
the B-pillar on the driver's side.
You can find more tire pressures for various
operating conditions in the tire pressure table
inside the filler flap.
Observe the information on tire pressure
when doing so (
Ypage 260).
XMake sure that the tire pressure is correct on
all four wheels.
XEnsure that the SmartKey is in position 2in
the ignition lock.
XPress the =or; button on the steering
wheel to select the Serv.menu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The multifunction display shows the current
tire pressure for each tire or the Tire pres‐
surewillbedisplayedafterdrivinga few minutesmessage appears.
XPress the:button.
The UseCurrentPressuresasNewRef‐erenceValuesmessage appears in the mul-
tifunction display.
If you wish to confirm the restart:
XPress the abutton.
The TirePress.MonitorRestartedmes-
sage 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 pres-
sures are then accepted as reference values
and monitored.
If you wish to cancel the restart:
XPress the %button.
The tire pressure values stored at the last
restart will continue to be monitored.
Tire pressure265
Wheels and tires
Z

Radio type approval for the tire pres-
sure monitor
CountryRadio type approval number
USAFCC ID: MRXGG4
FCC ID: MRXMC34MA4
CanadaIC: 2546A-GG4
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires can also impair the steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of
your vehicle. Never overload the tires by
exceeding the maximum load.
Two instruction labels on your vehicle show the maximum possible load.
(1) The Tire and Loading Information placard is on the B-pillar on the driver's side. The Tire
and Loading Information placard shows the
maximum permissible number of occu-
pants 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 iden-
tification 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 infor-
mation 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). Do not exceed
the maximum gross vehicle we ight o
r the
maximum gross axle weight rating for the
front or rear axle.
:B-pillar, driver's side
Maximum permissible gross mass
XSpecification for maximum permissible
load :is listed on the Tire and Loading Infor-
mation placard: "The combined weight of
occupants and cargo should never exceed
XXX kilograms or XXX lbs."
The gross weight of all vehicle occupants, cargo,
luggage and trailer load/noseweight (if applica-
ble) must not exceed the specified value.
iThe specifications shown on the Tire and
Loading Information placard in the illustration are examples. The maximum permissible load
is vehicle-specific and may deviate from the
data shown here. The maximum permissible
load that applies for your vehicle can be found
on your vehicle's Tire and Loading Informa-
tion placard.
266Loading the vehicle
Wheels and tires

Number of seats
Maximum number of seats:indicates the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Information plac-
ard.
iThe specifications shown on the Tire and
Loading Information placard in the illustration
are examples. The number of seats is vehicle-
specific and can differ from the details shown.
The number of seats in your vehicle can be
found on the Tire and Loading Information
placard.
Determining the correct load limit
Step-by-step instructions
The following steps have been developed as
required of all manufacturers under Title 49, Code of U.S. Federal Regulations, Part 575 pur-
suant to the "National Traffic and Motor Vehicle
Safety Act of 1966".
XStep 1: Locate the statement "The combined
weight of occupants and cargo should never
exceed XXX kg or XXX lbs." on your vehicle’s
Tire and Loading Information placard.
XStep 2: Determine the combined weight of
the driver and passengers that will be riding in your vehicle.
XStep 3: Subtract the combined weight of the
driver and passengers from XXX kilograms or
XXX lbs.
XStep 4: The resulting figure equals the avail-
able amount of cargo and luggage load capa-
city. Example: if the "XXX" amount equals
1400 lbs and there will be five 150 lbs pas-
sengers in your vehicle, the amount of avail-
able cargo and luggage load capacity is
650 lbs (1400 - 750 (5 x 150) = 650 lbs).
XStep 5: Determine the combined weight of
luggage and cargo being loaded on the vehi-
cle. That weight may not safely exceed the
available cargo and luggage load capacity cal- culated in step 4.
Example: steps 1 to 3
The following table shows examples on how to calculate total and cargo load capacities with varying
seating configurations and number and size of occupants. The following examples use a maximum
load of 1,500 lbs (680 kg). This is for illustration purposes only. Make sure you are using the
actual load limit for your vehicle stated on your vehicle's Tire and Loading Information placard
(
Ypage 266).
The greater the combined weight of the occupants, the lower the maximum luggage load.
Observe the additional information when towing a trailer (
Ypage 154).
Step 1
Example 1Example 2Example 3
Combined maximum
weight of occupants
and load (data from the
Tire and Loading Infor-
mation placard)1500 lbs (680 kg)1500 lbs (680 kg)1500 lbs (680 kg)
Loading the vehicle267
Wheels and tires
Z

Step 2
Example 1Example 2Example 3
Number of people in
the vehicle (driver and
occupants)531
Distribution of the
occupantsFront: 2
Rear: 3Front: 1
Rear: 2Front: 1
Weight of the occu-
pantsOccupant 1: 150 lbs
(68 kg)
Occupant 2: 180 lbs
(82 kg)
Occupant 3: 160 lbs
(73 kg)
Occupant 4: 140 lbs
(63 kg)
Occupant 5: 120 lbs
(54 kg)Occupant 1: 200 lbs
(91 kg)
Occupant 2: 190 lbs
(86 kg)
Occupant 3: 150 lbs
(68 kg)Occupant 1: 150 lbs
(68 kg)
Gross weight of all
occupants750 lbs (340 kg)540 lbs (245 kg)150 lbs (68 kg)
Step 3
Example 1Example 2Example 3
Permissible load (maxi-
mum gross vehicle
weight rating from the
Tire and Loading Infor-
mation placard minus
the gross weight of all
occupants)1500 lbs (680 kg)Ò
750 lbs (340 kg) =
750 lbs (340 kg)1500 lbs (680 kg) Ò
540 lbs (245 kg)
=960 lbs (435 kg)1500 lbs (680 kg) Ò
150 lbs (68 kg) =
1350 lbs (612 kg)
Vehicle identification plate
Even if you have calculated the total load care-
fully, 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 (
Ypage 266).
Gross vehicle weight rating: the gross weight
of the vehicle, all passengers, load and trailer
load/noseweight (if applicable) must not
exceed the gross vehicle weight rating.
Gross Axle Weight Rating (GAWR): the maxi-
mum permissible load 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, occu-
pants, load and full trailer load if applicable)
weighed on a suitable vehicle weighbridge.
268Loading the vehicle
Wheels and tires

All about wheels and tires
UniformTire Quality Grading Stand-
ards
Overview ofTire Quality Grading Stand-
ards
Uniform Tir eQuality Grading Standards are U.S.
governmen tspecifications. Their purpose is to
provid edriver swit hunifor mreliable information
on tire performance data. Tir emanufacturers
hav eto grad etires usin gthree performance fac -
tors: :tread wear grade, ;traction grad eand
= temperature grade. These regulation sdo no t
apply to Canada. Nevertheless, all tires sold in
North America are provided wit hth ecorre-
sponding qualit ygrading marking son th eside -
wall of th etire.
Quality grades can be found, wher eapplicable,
on th etire sidewall between tread shoulder and
maximum section width.
Example:
RTreadwear grade: 200
RTraction grade: AA
RTemperaturegrade: A
All passenger car tires mus tconform to th estat-
utory safet yrequirements in addition to these
grades.
iThe actual value sfor tires are vehicle-spe-
cific and may deviat efrom th evalue sin th e
illustration .
Treadwear
The treadwear grad eis acomparative rating
base don th ewear rat eof th etire when tested
under controlled condition son aspecifie dU.S.
governmen tcourse. Fo rexample, atire graded 15
0would wear on eand one-half times as well
on th egovernmen tcours eas atire graded 100.
The relative performance of tires depend supon
th eactual condition sof their use, however ,and
may depar tsignificantly from th enorm due to
variation sin drivin ghabits, servic epractice s
and difference sin road characteristics and cli -
mate.
Traction
GWARNIN G
The traction grad eassigned to this tire is
base don straight-ahead braking traction
tests, and does no tinclude acceleration ,cor-
nering, hydroplaning ,or peak traction char-
acteristics .
!Avoid wheelspin. This can lead to damag eto
th edrive train .
The traction grades –from highest to lowes t –
are AA ,A, Band C. Those grades represen tth e
tire' sabilit yto stop on wet pavemen tas meas -
ured under controlled condition son specifie d
governmen ttest surfaces of asphalt and con-
crete. Atire marke d Cmay hav epoor traction
performance .
The saf espee don awet ,snow covered or icy
road is always lower than on dry road surfaces.
You should pay special attention to road condi-
tion swhen temperatures are around freezing
point.
Mercedes-Benz recommends aminimum tread
dept hof ã in (4 mm) on all four winte rtires .
Observ eth elegally require dminimum tire tread
dept h (
Ypage 258). Winte rtires can reduce th e
braking distanc eon snow-covered surfaces in
comparison wit hsummer tires .The braking dis-
tance is still muc hfurther than on surfaces that
are no ticy or covered wit hsnow. Tak eappro-
priate car ewhen driving.
Further information on winte rtires (M+ Stires )
(
Ypage 259).
Temperature
GWARNIN G
The temperature grad efor this tire is estab-
lished for atire that is properly inflated and
no toverloaded. Excessive speed, underinfla-
tion ,or excessive loading ,either separately or
All about wheels and tires269
Wheels and tires
Z

in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C, representing 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. Sus-
tained 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
Overview of tire labeling
:Uniform Tire Quality Grading Standard
(Ypage 273)
;DOT, Tire Identification Number
(Ypage 272)
=Maximum tire load (Ypage 272)
?Manufacturer
AMaximum tire pressure (Ypage 262)
BTire material (Ypage 273)
CTire size designation, load-bearing capacity
and speed rating (Ypage 270)
DLoad index (Ypage 272)
ETire name The markings described above are on the tire in
addition to the tire name (sales designation) and
the manufacturer's name.
iTire data is vehicle-specific and may deviate
from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
:Tire width
;Height-width ratio in percentage
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, a letter is imprinted into the tire wall before the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: passenger
vehicle tires according to U.S. manufacturing
standards.
If "P" precedes the size description: light truck
tires according to U.S. manufacturing stand-
ards.
270All about wheels and tires
Wheels and tires