2017 MERCEDES-BENZ GLC tire pressure

Important notes on tire pressure
G WARNIN G
If th e tire pressur e drops repeatedly, th e
wheel, valv e or tire may be damaged. Tir e
pressur e that is to o low may result in a tire
blow-out . Ther e is a ris k of an accident.R
Chec k th e tire for foreign objects .R
Chec k whether th e whee l is losing air or th e
valv e is leaking .
If you are unable to rectify th e damage, con-
tac t a qualified specialist workshop.
G WARNIN G
If you fit unsuitable accessories onto tire
valves, th e tire valves may be overloaded and
malfunction , whic h can caus e tire pressur e
loss . Due to their design , retrofitte d tire pres-
sur e monitors keep th e tire valv e open . This
can also result in tire pressur e loss . Ther e is a
ris k of an accident.
Only screw th e standard valv e cap or other
valv e cap s approve d by Mercedes-Ben z for
your vehicl e onto th e tire valve.
Use a suitable pressur e gauge to chec k th e tire
pressure. The outer appearanc e of a tire does
no t permit any reliable conclusio n about th e tire
pressure. On vehicles equipped wit h th e elec -
tronic tire pressur e monitor, th e tire pressur e
can be checke d in th e on-board computer.
The tire temperature and pressur e increas e
when th e vehicl e is in motion . This is dependen t
on th e driving spee d and th e load.
Therefore, you should only correc t tire pres-
sures when th e tires are cold.
The tires are cold: R
if th e vehicl e has been parked wit h th e tires
out of direct sunligh t for at least three hour s
and R
if th e vehicl e has no t been driven further than
1 mile (1. 6 km)
The tire temperature changes depending on th e
outside temperature, th e vehicl e spee d and th e
tire l oad. If th e ti
re temperature changes by
18 ‡ (10 †), th e tire pressur e changes by
approximately 10 kP a (0. 1 bar/1.5 psi) . Tak e
this int o accoun t when checkin g th e pressur e of
warm tires . Only correc t th e tire pressur e if it is to o low for th e curren t operating conditions. If
you chec k th e tire pressur e when th e tires are
warm , th e resulting value will be higher than if
th e tires were cold. This is normal. Do no t
reduce th e tire pressur e to th e value specifie d
for cold tires . The tire pressur e would otherwise
be to o low.
Observ e th e recommended tire pressures for
cold tires : R
on th e Tir e and Loading Information placard
on th e B-pillar on th e driver' s sideR
in th e tire pressur e table on th e fuel filler flap
( Y
page 149)
Underinflated or overinflated tires
Underinflated tires
G WARNIN G
Tires wit h pressur e that is to o low can over-
heat and burs t as a consequence . In addition ,
they also suffer from excessiv e and/o r irreg-
ular wear , whic h can severely impair th e brak -
ing properties and th e driving characteristics .
Ther e is a ris k of an accident.
Avoid tire pressures that are to o low in all th e
tires , includin g th e spar e wheel.
Underinflated tires may: R
overheat, leadin g to tire defects R
adversely affec t handlin gR
wear excessively and/o r unevenlyR
hav e an adverse effec t on fuel consumption
Overinflated tires
G WARNIN G
Tires wit h excessively high pressur e can burs t
because they are damaged mor e easil y by
road debris, pothole s etc. In addition , they
also suffer from irregular wear , whic h can
severely impair th e braking properties and th e
driving characteristics . Ther e is a ris k of an
accident.
Avoid tire pressures that are to o high in all th e
tires , includin g th e spar e wheel.Tire pressure 341
Wheels and tires Z

Overinflated tires may: R
increase the braking distance R
adversely affect handling R
wear excessively and/or unevenly R
have an adverse effect on ride comfort R
be more susceptible to damage
Maximum tire pressures
C
Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure ( Y
page 339).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes Observe the notes on tire pressure
( Y
page 339).
Information on air pressure for the tires on your
vehicle can be found: R
on the vehicle's Tire and Loading Information
placard on the B-pillar R
in the tire pressure table in the fuel filler flap
( Y
page 149)R
in the "Tire pressure" section Checking tire pressures manually To determine and set the correct tire pressure,
proceed as follows: X
Remove the valve cap of the tire that is to be
checked. X
Press the tire pressure gauge securely onto
the valve. X
Read the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
( Y
page 339). X
If the tire pressure is too low, increase the tire
pressure to the recommended value. X
If 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. X
Screw the valve cap onto the valve. X
Repeat these steps for the other tires.
Tire pressure loss warning system
General notes While the vehicle is in motion, the tire pressure
loss warning system monitors the set tire pres-
sure using the rotational speed of the wheels.
This enables the system to detect significant
pressure loss in a tire. If the speed of rotation of
a wheel changes as a result of a loss of pressure,
a corresponding warning message will appear in
the multifunction display.
You can recognize the tire pressure loss warning
by the Run Flat Indicator Active Press
'OK' to Restart message which appears in
the Service menu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section ( Y
page 343).
Important safety notes
The tire pressure warning system does not warn
you of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y
page 339).
The tire pressure loss warning does not replace
the need to regularly check the tire pressure. An
even loss of pressure on several tires at the342
Tire pressure
Wheels and tires

same time cannot be detected by the tire pres-
sure loss warning system.
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 function of the tire pressure loss warning
system is limited or delayed if: R
snow chains are mounted on your vehicle's
tires. R
road conditions are wintry. R
you are driving on sand or gravel. R
you adopt a very sporty driving style (corner-
ing at high speeds or driving with high rates of
acceleration). R
you are towing a very heavy or large trailer. R
you are driving with a heavy load (in the vehi-
cle or on the roof).
Restarting the tire pressure loss warn-
ing system Restart the tire pressure loss warning system if
you have: R
changed the tire pressure R
changed the wheels or tires R
mounted new wheels or tires X
Before restarting, make sure that the tire
pressures are set properly on all four tires for
the respective operating conditions.
The recommended tire pressure can be found
on the Tire and Loading Information placard
on the B-pillar. Additionally, a tire pressure
table is attached to the fuel filler flap. The tire
pressure loss warning system can only give
reliable warnings if you have set the correct
tire pressure. If an incorrect tire pressure is
set, these incorrect values will be monitored. X
Also observe the notes in the section on tire
pressures ( Y
page 339).X
Make sure that the SmartKey is in position H
in the ignition lock ( Y
page 132).X
Press

Information on the message display can be
found in the "Checking the tire pressure elec-
tronically" section ( Y
page 345).
Important safety notes
G WARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure 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, if available, 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 lights up,
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 stopping ability. Please note that
the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to trigger illumination of the TPMS low tire pres-
sure telltale.
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 sys-
tem 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 illu-
minated, 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 incom-
patible 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.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
( Y
page 339). 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 ( Y
page 345). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the tire
pressure drops significantly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
( Y
page 339).
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
su dden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.344
Tire pressure
Wheels and tires

The tire pressure monitor has a yellow warning
lamp in the instrument cluster for indicating
pressure loss or a malfunction. Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning: R
if the warning lamp is lit continuously, the tire
pressure on one or more tires is significantly
too low. The tire pressure monitor is not mal-
functioning. R
if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
( Y
page 250).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashing for approximately
one minute and then remaining lit. When the
malfunction has been rectified, the tire pressure
warning lamp goes out after a few minutes of
driving.
The tire pressure values indicated by the on-
board computer may differ from those 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 X
Make sure that the SmartKey is in position H
( Y
page 132) in the ignition lock. X
Press

for monitoring. In most cases, the tire pressure
monitor will automatically detect the new refer-
ence values after you have changed the tire
pressure. However, you can also set reference
values manually as described here. The tire
pressure monitor then monitors the new tire
pressure values. X
Set 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 ( Y
page 339).X
Make sure that the tire pressure is correct on
all four wheels. X
Make sure that the SmartKey is in position H
in the ignition lock ( Y
page 132).X
Press

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, e.g. when buying new tires. You
can find information on this under "Tires"
( Y
page 360).
Further information about reading tire data can
be obtained from any qualified specialist work-
shop.
Load index
In addition to the load-bearing index, load
index C may also be imprinted on the sidewall
of the tire. You will find this after the letter that
identifies the speed rating ( Y
page 351).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
i Tire data is vehicle-specific and may deviate
from the data in the example. Maximum load rating
Maximum tire load C is the maximum permis-
sible weight for which the tire is approved.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible
load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side ( Y
page 346).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
DOT, Tire Identification Number (TIN) US tire regulations stipulate that every tire man-
ufacturer or retreader must 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 or retreaders
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 identifica-
tion code D , tire size

Speed rating The speed rating is part of the tire identification.
It specifies the speed range for which the tire is
approved.
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 vehi-
cle weight rating GVWR as specified on the vehi-
cle identification plate on the B-pillar on the
driver's side.
GVWR (Gross Vehicle Weight Rating) The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the 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 loaded vehicle weight The maximum weight is the sum of: R
the curb weight of the vehicle R
the weight of the accessories R
the load limit R
the weight of the factory installed optional
equipment
Kilopascal (kPa) Metric unit for tire pressure. 6.9 kPa corre-
sponds to 1 psi. Another unit for tire pressure is
bar. 100 kilopascals (kPa) are 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. It also includes the air-conditioning sys-
tem and optional equipment if these are instal-
led in the vehicle, but does not include passen-
gers or luggage. Maximum load rating The maximum tire load is the maximum permis-
sible 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) A standard unit of measure for tire pressure.
Aspect ratio Relationship between tire height and tire width
in percent.
Tire pressure This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. 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.
Cold tire pressure The tires are cold: R
if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and R
if the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
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
bead.All about wheels and tires 355
Wheels and tires Z