MERCEDES-BENZ CLA-Class 2014 C117 Owner's Manual
Page 321 of 358
If the tire pressures have been set to the
lower values for lighter loads and/or lower
road speeds, the pressures should be reset to
the higher values:
R if you want to drive with an increased load
and/or
R if you want to drive at higher road speeds
i The tire pressures for increased loads
and/or higher road speeds, shown in the
tire pressure table, may have a negative
effect on driving comfort.
If the tire pressure is not set correctly, this
can lead to an excessive build up of heat and
a sudden loss of pressure.
For more information, contact a qualified spe- cialist workshop. Important notes on tire pressure
G
WARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident. R Check the tire for foreign objects.
R Check whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop. G
WARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres-
sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the
tire pressure. The outer appearance of a tire
does not permit any reliable conclusion about the tire pressure.
The tire temperature and pressure increase
when the vehicle is in motion. This is depend-
ent on the driving speed and the load.
Therefore, you should only correct tire pres-
sures when the tires are cold.
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has not been driven further
than 1 mile (1.6 km)
The tire temperature changes depending on
the outside temperature, the vehicle speed
and the tire load. If the tire temperature
changes by 18 ‡ (10 †), the tire pressure
changes by approximately 10 kPa (0.1 bar/
1.5 psi). Take this into account when check-
ing the pressure of warm tires. Only correct
the tire pressure if it is too low for the current operating conditions. If you check the tire
pressure when the tires are warm, the result-ing value will be higher than if the tires were
cold. This is normal. Do not reduce the tire
pressure to the value specified for cold tires.
The tire pressure would otherwise be too low.
Observe the recommended tire pressures for
cold tires:
R on the Tire and Loading Information placard
on the B-pilla ron the driver's side
R in the tire pressure table on the inside of the
fuel filler flap Tire pressure
319Wheels and tires Z
Page 322 of 358
Underinflated or overinflated tires
Underinflation G
WARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition, they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak- ing properties and the driving characteristics.There is a risk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
R wear quickly and unevenly
R have an adverse effect on fuel consumption
R overheat, leading to tire defects
R have an adverse effect on handling charac-
teristics
Overinflation G
WARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the braking properties and the driving characteristics. There is a risk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may: R have an adverse effect on handling charac-
teristics
R wear quickly and unevenly
R be more susceptible to damage
R have an adverse effect on ride comfort
R increase the braking distance
Maximum tire pressures Never exceed the maximum permissible tire
inflation pressure. Always observe the rec- ommended tire pressure for your vehicle
when adjusting the tire pressure
(Y
page 317). 0043
Example: maximum permissible tire pres-
sure
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Checking the tire pressures
Important safety notes Observe the "Tire pressure information" sec-
tion (Y page 317).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading Informa-
tion placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure information" section
Checking tire pressures manually To determine and set the correct tire pres-
sure, 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 with
the recommended value on the Tire and 320
Tire pressureWheels and tires
Page 323 of 358
Loading Information placard on the B-pillar
on the driver's side of your vehicle.
X If necessary, increase the tire pressure to
the recommended value (Y page 317).
X If the tire pressure is too high, release air by
pressing 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 gauge.
X Screw the valve cap onto the valve.
X Repeat 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 pres-
sure monitor warns you if the pressure drops
in one or more of the tires. The tire pressure
monitor only functions if the correct sensors
are installed on all wheels.
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 Service Servicemenu of the mul-
tifunction display. Example: current tire pressure display
For information on the message display, refer to the "Checking the tire pressure electroni-
cally" section (Y page 322).
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 Tire pressure
321Wheels and tires
Z
Page 324 of 358
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 317). Note that the correct tire pres-
sure for the current operating situation must
first be taught-in to the tire pressure monitor.
If there is a substantial loss of pressure, the
warning threshold for the warning message is aligned to the reference values taught-in.
Restart the tire pressure monitor after adjust-
ing the pressure of the cold tires
(Y page 323). The current pressures are
saved as new reference values. As a result, a warning message will appear if the tire pres-
sure 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 317).
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 maneuvers.
The tire pressure monitor has a yellow warn-
ing lamp in the instrument cluster for indicat-
ing a pressure loss or malfunction. Whether
the warning lamp flashes or lights up indi-
cates 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 signif-
icantly too low. The tire pressure monitor is
not malfunctioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
i In addition to the warning lamp, a mes-
sage appears in the multifunction display. Further information can be found on
(Y
page 237).
If the tire pressure monitor is malfunctioning,
it may take more than ten minutes for the tire pressure warning lamp to inform you of the
malfunction by flashing for approximately one
minute and then remaining lit. When the mal- function 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 val-
ues 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 trans-
mitting 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
2 in the ignition lock (Y page 141).
X Press the 0059or0065 button on the steer-
ing wheel to select the Service Servicemenu.
X Press the 0063or0064 button to select
Tire Pressure
Tire Pressure.
X Press the 0076button.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle was parked for longer than
20 minutes, the Tire pressure will be
Tire pressure will be
displayed after driving a few displayed after driving a few
minutes minutes message is shown.
After a teach-in process, the tire pressure
monitor 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, the Tire Pressure Tire Pressure322
Tire pressureWheels and tires
Page 325 of 358
Monitor Active
Monitor Active
message is shown instead
of the tire pressure display. The tire pressures
are already being monitored.
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 and the yellow tire pressure monitor warning light
comes on.
R If the Correct Tire Pressure
Correct Tire Pressure message
appears in the multifunction display, the
tire pressure in at least one tire is too low
and must be corrected at the next oppor-
tunity.
R If the Check Tire Pressure Soon Check Tire Pressure Soon mes-
sage appears in the multifunction display,
the tire pressure in one or more tires has
dropped significantly and the tires must be checked.
R If the Tire Pressure Warning Tire
Tire Pressure Warning Tire
Failure
Failure message appears in the multi-
function display, the tire pressure in one or
more tires has dropped suddenly and the
tires must be checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
(Y page 237).
i If the wheel positions on the vehicle are
rotated, the tire pressures may be dis-
played 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 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 refer-
ence 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 define 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 recom-
mended for the corresponding driving sit-
uation on the Tire and Loading Information
placard on the driver's side
B-pillar (Y page 317).
Additional tire pressure values for different loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(Y page 317).
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 the 0059or0065 button on the steer-
ing wheel to select the Service
Service menu.
X Press the 0063or0064 button to select
Tire Pressure Tire Pressure.
X Press the 0076button.
The multifunction display shows the cur-
rent tire pressure for each tire or the Tire Tire
pressure will be displayed after
pressure will be displayed after
driving a few minutes driving a few minutes message.
X Press the 0064button.
The multifunction display shows the Use
Use
Current
Current Pressures
Pressures as
asNew
New Reference
Reference
Values
Values message.
If you wish to confirm the restart:
X Press the 0076button.
The Tire Press. Monitor Restarted
Tire Press. Monitor Restarted
message appears in the multifunction dis-
play.
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 0038button.
The tire pressure values stored at the last
restart will continue to be monitored. Tire pressure
323Wheels and tires Z
Page 326 of 358
Loading the vehicle
Instruction labels for tires and loads
G
WARNING
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. 0043
B-pillar, driver's side
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 occupants and the maximum permis-
sible vehicle load. It also contains details
of the tire sizes and corresponding pres-
sures 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 occu-
pants, 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 maxi-
mum gross axle weight rating for the
front or rear axle. Maximum permissible gross vehicle
weight rating
X
Specification for maximum gross vehicle
weight 0043is listed in the Tire and Loading
Information placard: "The combined weight of occupants and cargo should never
exceed XXX kilograms or XXX lbs."
The gross weight of all vehicle occupants,
load, luggage and trailer load/noseweight (if
applicable) must not exceed the specified
value.
i The specifications shown on the Tire and
Loading Information placard in the illustra-
tion are examples. The maximum permis-
sible load is vehicle-specific and may devi-
ate from the data shown here. The maxi-
mum permissible load that applies for your vehicle can be found on your vehicle's Tire
and Loading Information placard. 324
Loading the vehicleWheels and tires
Page 327 of 358
Number of seats
Maximum number of seats
0043indicates the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Information
placard.
i The specifications shown on the Tire and
Loading Information placard in the illustra-
tion 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 Load-
ing 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
pursuant to the "National Traffic and Motor
Vehicle Safety Act of 1966".
X Step 1: Locate the statement "The com-
bined weight of occupants and cargo
should never exceed XXX kg or XXX lbs." on your vehicle’s Tire and Loading Information
placard.
X Step 2: Determine the combined weight of
the driver and passengers that will be riding
in your vehicle.
X Step 3: Subtract the combined weight of
the driver and passengers from XXX kilo-
grams or XXX lbs. X
Step 4: The resulting figure equals the
available amount of cargo and luggage load capacity. For example, if the "XXX" amount
equals 1,400 lbs and there will be five
150-l b passengers in your vehicle, the
amount of available cargo and luggage load
capacity is 650 lbs (1,400 00F8750 (5 x 150) =
650 lbs).
X Step 5: Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely exceed
the available cargo and luggage load capa- city calculated in step 4.
X Step 6 (if applicable): If your vehicle will
be towing a trailer, load from your trailer
will be transferred to your vehicle. Refer to this Operator's Manual to determine how
this reduces the available cargo and lug-
gage load capacity of your vehicle
(Y page 327). Loading the vehicle
325Wheels and tires Z
Page 328 of 358
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 usea 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 Infor- mation placard (Y page 325).
The greater the combined weight of the occupants, the lower the maximum luggage load. Example 1 Example 2 Example 3
Step 1 Combined maximum
weight of occupants
and cargo (data from
the Tire and Loading
Information placard) 1500 lbs
(680 kg) 1500 lbs
(680 kg) 1500 lbs
(680 kg)
Example 1 Example 2 Example 3
Step 2 Number of people in
the vehicle (driver
and occupants)
5 3 1
Distribution of the
occupants
Front: 2
Rear: 3 Front: 1
Rear: 2 Front: 1
Weight of the occu-
pants
Occupant 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
occupants
750 lbs (340 kg) 540 lbs (245 kg) 150 lbs (68 kg)326
Loading the vehicleWheels and tires
Page 329 of 358
Example 1 Example 2 Example 3
Step 3 Permissible load and
trailer load/nose-
weight (maximum
permissible load rat-
ing from the Tire and Loading Information
placard minus the
gross weight of all
occupants) 1500 lbs
(680 kg)
00F8
750 lbs (340 kg) = 750 lbs
(340 kg) 1500 lbs
(680 kg)
00F8
540 lbs (245 kg) =960 lbs
(435 kg) 1500 lbs
(680 kg) 00F8
150 lbs (68 kg) = 1350 lbs
(612 kg) Vehicle identification plate
Even if you have calculated the total cargo
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 324).
Permissible gross vehicle weight: the
gross weight of the vehicle, all passengers,
load and trailer load/noseweight (if applica-
ble) must not exceed the permissible gross
vehicle weight.
Gross axle weight rating: the maximum per-
missible 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 vehi-
cle 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 between
10 %a nd 15% of the gross weight of the trailer
and its load. Maximum load rating
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
ble load can be found on the vehicle's Tire and Loading Information placard on the B-pillar onthe driver's side (Y page 324). Maximum tire load
0043is the maximum per-
missible weight for which the tire is approved.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Maximum load rating
327Wheels and tires Z
Page 330 of 358
Uniform Tire Quality Grading Stand-
ards Overview of Tire Quality Grading
Standards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their pur-
pose is to provide drivers with uniform relia-
ble information on tire performance data. Tire
manufacturers have to grade tires using three
performance factors: tread wear 0043, tire trac-
tion 0044, and heat resistance 0087. These regu-
lations do not apply to Canada. Nevertheless,
all tires sold in North America are provided
with the corresponding quality grading mark- ings on the sidewall of the tire.
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Where applicable, the tire grading informa-
tion can be found on the tire sidewall between
the tread shoulder and maximum tire width.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
For example: Treadwear Traction Temperature
200 AA A
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested under controlled conditions on a specified
U.S. government course. For example, a tire
graded 150 would wear one and one-half
times as well on the government course as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use, how-
ever, and may depart significantly from the
norm, due to variations in driving habits, ser-
vice practices and differences in road char-
acteristics 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, cor- nering, hydroplaning, or peak traction char-
acteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
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.
The safe speed on a wet, snow covered or icy road is always lower than on dry road surfa-
ces.
You should pay special attention to road con-
ditions when temperatures are around the
freezing point.
Mercedes-Benz recommends a minimum
tread depth of 00CFin (4 mm) for all four winter
tires (Y page 316) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow-covered surfaces in comparison with summer tires.
Stopping distance, however, is still consider-
ably greater than when the road is not cov-
ered with ice or snow. Take appropriate care
when driving.
! Avoid wheelspin. This can lead to damage
to the drive train. 328
Uniform Tire Quality Grading StandardsWheels and tires