2014 MERCEDES-BENZ CLA tire size

Tire pressure
Tire pressure specifications
GWARNING
Underinflated or overinflated tires pose the
following risks:
Rthe tires may burst, especially as the load
and vehicle speed increase.
Rthe tires may wear excessively and/or
unevenly, which may greatly impairtire
traction.
Rthe driving characteristics, as well as
steering and braking, may be greatly
impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and checkthe pressure of all the tires
including the spare wheel:
Rmonthly, at least
Rif the load changes
Rbefore beginning a long journey
Runder different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
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. On vehicles equipped with
the electronic tire pressure monitor, the tire
pressure can be checked in the on-board
computer.
The recommended tire pressures for the tires
mounted at the factory can be found on the
labels described here.
1.)Tire and Loading Information placard
on the B-pillar on the driver's side of the
vehicle (Ypage 323).
The Tire and Loading Information placard
contains the recommended tire pressures for
cold tires. The recommended tire pressures
are valid for the maximum permissible load
and up to the maximum permissible vehicle
speed.
Recommended tire pressures
Option 2)Tire pressure tableon the inside
of the fuel filler flap.
The tire pressure table contains the
recommended pressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions.
iSpecifications shown in the examples of
tire pressure tables are for illustration
purposes only. Tire pressure specifications
are vehicle-specific and may deviate from
the data shown here. Tire pressure
specifications applicable to your vehicle
are located in your vehicle's tire pressure
table.
Example: tire pressure table for all tires permittedfor this vehicle by the factory
If a tire size precedes a tire pressure, the tire
pressure information following is only valid
for that tire size. The load conditions "partially
laden" and "fully laden" are defined in the
table for different numbers of occupants and
amounts of luggage. The actual number of
seats may differ.
316Tire pressure
Wheels and tires

Example: tire pressure table with tire dimensions
Some tire pressure tables showonly the rim
diameters instead of the full tire size, e.g.
R18.Rim diameter is part of the tire size and
can be found on the tire sidewall
(Ypage 330).
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:
Rif you want to drive with an increased load
and/or
Rif you want to drive at higher road speeds.
iThe 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 excessivebuild up of heat and
a suddenloss of pressure.
For more information, contact a qualified
specialist workshop.
Important notes on tire pressure
GWARNING
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.
RCheck the tire for foreign objects.
RCheck whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage,
contact a qualified specialist workshop.
GWARNING
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
pressure 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
dependent on the driving speed and the load.
Therefore, you should only correct tire
pressures when the tires are cold.
The tires are cold:
Rif the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
Rif 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
Tire pressure317
Wheels and tires
Z

XBefore restarting, make sure that the tire
pressures are set properly on all fourtires
for the respective operating conditions.
The recommended tire pressures can be
found on the Tire and Loading Information
placard on the B-pillar on the driver's side
or the tire pressure table on the fuel filler
flap. The tire pressure loss warning system
can only give reliable warnings if you have
set the correct tirepressure. If an incorrect
tire pressure is set, these incorrect values
will be monitored.
XAlso observe the notes in the section on tire
pressures (Ypage 316).
XMake sure that the SmartKey is in position
2in the ignitionlock (Ypage 137).
XPressoron the steering wheel
to select theServicemenu.
XPress theorbutton to select
Tire Pressure.
XPress thebutton.
TheRun Flat Indicator Active
Press 'OK' to Restartmessage
appears in the multifunction display.
If you wish to confirm the restart:
XPress thebutton.
TheTire Pressure Now OK?message
appears in the multifunction display.
XPress theorbutton to select
Yes.
XPress thebutton.
TheRun Flat Indicator Restarted
message appears in the multifunction
display.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.
If you wish to cancel the restart:
XPress thebutton.
or
XWhen theTire Pressure Now OK?
message appears, press the
orbutton to selectCancel.
XPress thebutton.
The tire pressure values stored at the last
restart will continue to be monitored.
Tire pressure monitor
General notes
If a tire pressure monitor is installed, the
vehicle's wheels have sensors that monitor
the tire pressures in all four tires. The tire
pressure 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 shownintheServicemenu of the
multifunction display. For further information
on displaying this message, refer to the
"Checking the tire pressure electronically"
section (Ypage 322).
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
recommended 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
Information 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
pressure telltale when one or more of your
320Tire pressure
Wheels and tires

XSet the tire pressure to the value
recommended for the corresponding
driving situation on the Tire and Loading
Information placard on the driver's side
B-pillar (Ypage 316).
Additional tire pressure values for different
loads can also be found on the tire pressure
table on the inside of the fuel fillerflap
(Ypage 316).
XMake sure that the tire pressure is correct
on all four wheels.
XMake sure that the SmartKey is in position
2in the ignition lock.
XPress theorbutton on the
steering wheel to selecttheService
menu.
XPress theorbutton to select
Tire Pressure.
XPress thebutton.
The multifunction display shows the
current tire pressure for the individual tires
or theTire pressure will be
displayed after driving a few
minutesmessage.
XPress thebutton.
TheUse Current Pressures as New
Reference Valuesmessage appears in
the multifunction display.
If you wish to confirm the restart:
XPress thebutton.
TheTire Press. 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:
XPress thebutton.
The tire pressure values stored at the last
restart will continue to be monitored.
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.
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
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.
Loading the vehicle323
Wheels and tires
Z

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 1500 lbs (680kg).This is forillustration 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 324).
The greater the combined weight of the occupants, the lower the maximum luggage load.
Example 1Example 2Example 3
Step 1Combined 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 1Example 2Example 3
Step 2Number of people in
the vehicle (driver
and occupants)
531
Distribution of the
occupants
Front: 2
Rear: 3
Front: 1
Rear: 2
Front: 1
Weight of the
occupants
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)
326Loading the vehicle
Wheels and tires

not covered with ice or snow. Take
appropriate care when driving.
!Avoid wheelspin. This can lead to damage
to the drive train.
Temperature
GWARNING
The temperature grade for this tire is
established for a tire thatis properly inflated
and not overloaded.Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heatbuild-up and possible tire
failure.
The temperature grades areA(the highest),
B, and C. These represent the tire's
resistance to the generationofheat 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 gradeCcorresponds 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
The following markings are on the tire in additionto the tire name (sales designation) and themanufacturer's name:
Uniform tire Quality Grading Standard
(Ypage 333)
DOT, Tire Identification Number
(Ypage 332)
"Maximum tire load (Ypage 327)
!Maximum tire pressure (Ypage 318)
Manufacturer
Tire material (Ypage 333)
Tire size designation, load-bearing
capacity and speed index (Ypage 330)
Load index (Ypage 332)
Tire name
iTire data is vehicle-specific and may
deviate from the data in the example.
Tire labeling329
Wheels and tires
Z

Tire size designation,load-bearing
capacity and speed rating
Tire width
Nominal aspectratio in %
"Tire code
!Rim diameter
Load bearing index
Speed rating
iTire 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 letterthat 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 widthshows the nominal
tire width in millimeters.
Nominal aspect ratio:aspect ratiois the
size ratio between the tire height and the tire
width and is shown in percent.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 149mph (240km/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
is a numerical code which specifies the
maximum load-bearing capacity of a tire.
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
(Ypage 323).
Example:
Aload-bearing index of 91 indicates a
maximum load of 1,356lb (615kg) that can be
carried by the tires. For further information on
the maximum tire load in kilograms and
pounds, see (Ypage 327).
For further information on the load-bearing
index, see Load index (Ypage 332).
Speed rating:speed rating specifies the
approved maximum speed of the tire.
GWARNING
Exceeding the stated tire load-bearing
capacity 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.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
330Tire labeling
Wheels and tires

adapt your driving style to the traffic
conditions.
Summer tires
IndexSpeed rating
Qup to 100mph (160 km/h)
Rup to 106mph (170 km/h)
Sup to 112mph (180 km/h)
Tup to 118mph (190 km/h)
Hup to 130mph (210 km/h)
Vup to 149mph (240 km/h)
Wup to 168mph (270 km/h)
Yup to 186mph (300 km/h)
ZR...Yup to 186mph (300 km/h)
ZR...(..Y)over 186mph (300 km/h)
ZRover 149mph (240 km/h)
ROptionally, tires with a maximum speed of
over149 mph(240km/h) may have "ZR" in
the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specifications consist of load
bearing indexand speed rating .
RIf the size description of yourtire 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 (300km/h).
RThe size description for all tires with
maximum speeds of over 186mph
(300km/h) must include "ZR",andthe
service specification must be given in
brackets. Example: 275/40 ZR 18 (99 Y).
The speed rating "(Y)" indicates that the
maximum speed of the tire is over 186mph
(300km/h). Ask the tire manufacturer
about the maximum speed.
All-weather tires and winter tires
IndexSpeed rating
Q M+S5up to 100mph (160 km/h)
T M+S5up to 118mph (190 km/h)
H M+S5up to 130mph (210 km/h)
V M+S5up to 149mph (240 km/h)
iNot all tires with the M+S marking provide
the driving characteristics of winter tires.
Winter tires have, in additionto the M+S
identification, thesnow flake symbol
on the tire sidewall. Tires with this marking
fulfill the requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC)
regarding the tire traction on snow. They
have been especially developed for driving
on snow.
An electronic speed limiter prevents your
vehicle from exceeding a speed of 130mph
(210km/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, e.g. when buying new tires. The
required speed rating for your vehicle can be
found in the "Tires" section (Ypage 340).
Further information about reading tire data
can be obtained from any qualified specialist
workshop.
5Or M+Sfor winter tires.
Tire labeling331
Wheels and tires
Z