2018 MERCEDES-BENZ CLA COUPE wheel size

mation placard and tire pressure table on the
vehicle.
General notes
The recommended tire pressures for the tires
mounted at the factory can be found on the
labels described here.
Operation with an emergency spare wheel:
informationonoperation with an emergency
spare wheelc an be found in the general notes in
the "Emergency spare wheel" section
(
Ypage 312).
Further informatio nontire pressures can be
obtained at aqualified specialist workshop.
Tire and Loading Information placard
:Recommended tire pressures
The Tire and Loading Information placard is on
the B-pillar on the driver'ss ide (
Ypage 298).
The Tire and Loading Information placard con-
tains the recommended tire pressures for cold
tires. The recommended tire pressures are valid
for the maximu mpermissiblel oadand up to the
maximu mpermissiblev ehiclespeed.
Tire pressure table
The tire pressure table is on the inside of the fuel
filler flap .Itshows the tire pressure for all tires
permitted at the factory for this vehicle; see
illustratio n(example).
The tire pressure table contains the recommen-
ded pressures for cold tires for various operat-
ing conditions, i.e. differing loada nd speed con-
ditions.
If at ire size precedesat ire pressure, the fol-
lowing tire pressure informatio nisonly vali dfor
that tire size; see illustratio n(example).
The loadc onditions "partiall yladen" and "fully
laden" are defined in the table for different num-
bers of occupants and amounts of luggage .The
actua lnumber of seats may differ.
Some tire pressure table sshow only 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 sidewal l(
Ypage 302).
Tire pressure291
Wheelsand tires
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shown in theServ.menu of the multifunction
display, see illustration (example).
For information on the message display, refer to
the "Checking the tire pressure electronically"
section (
Ypage 296).
Important safety notes
GWARNING
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 adifferent size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label,y ou should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with atire pressure monitoring
system (TPMS) that illuminates alow 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,a nd inflate them to the proper
pressure. Driving on asignificantly 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 asubstitute 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 amalfunction, the warning lamp
will flash for approximately aminute 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 avariety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioningp roperly. 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
(
Ypage 290). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If asub-
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 297). The current pres-
sures are saved as new reference values. As a
result, awarning message will appearift he 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
(
Ypage 290).
The tire pressure monitor is not able to warn you
of as udden loss of pressure, e.g. if the tire is
penetrated by aforeign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully.A void abrupt steering
movements.
Tire pressure295
Wheels and tires
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Maximum permissible gross vehicle
weight rating
XSpecification for maximumgross vehicle
weight :is listed in the Tire and Loading
Informatio nplacard: "The combined weight of
occupants and cargo should never exceed
XXX kilograms or XXX lbs."
The gross weight of all vehicleo ccupants, load
and luggage must not exceed the specified
value.
iThe specifications shownont he Tire and
Loading Informatio nplacard in the illustration
are examples. The maximu mpermissible
gross vehiclew eight rating is vehicle-specific
and may differf rom that in the illustration.
You can find the vali dmaximu mpermissible
gross vehiclew eight rating for you rvehicleo n
the Tire and Loading Informatio nplacard.
Number of seats
Maximu mnumber of seats :indicates the
maximu mnumber of occupants allowedt o
travel in the vehicle. This information can be
found on the Tire and Loading Informatio nplac-
ard.
iThe specifications shownont he Tire and
Loading Informatio nplacard in the illustration
are examples. The number of seats is vehicle-
specific and can differf rom the details shown.
The number of seats in you rvehiclec an be
found on the Tire and Loading Information
placard.
Determiningt he correct load limit
Step-by-ste pinstructions
The following steps have been developed as
required of all manufacturers under Title 49,
Cod eofU .S. FederalR egulations, Part 575 pur-
suant to the "National Traffi cand 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 you rvehicle’s
Tire and Loading Informatio nplacard.
XStep 2: Determine the combined weight of
the drivera nd passengers that wil lberiding in
you rvehicle.
XStep 3: Subtract the combined weight of the
drivera nd passengers from XXX kilograms or
XXX lbs.
XStep 4: The resulting figure equals the avail-
abl eamount of cargo and luggage loadc apa-
city. For example, if the "XXX "amount equals
1400 lbs and there wil lbefive 150-lb pas-
sengers in you rvehicle, the amount of avail-
abl ecargo and luggage loadc apacity is
650 lbs (1400 -750 (5 x150) = 650 lbs).
XStep 5: Determine the combined weight of
luggage and cargo being loaded on the vehi-
cle. That weight may not safel yexceed the
available cargo and luggage loadc apacity cal-
culated in step 4.
Example:s teps1to3
The following table showse xamples on how to calculate total and cargo loadc apacities with varying
seating configurations and number and size of occupants. The following examples use aloadl imito f
Loading the vehicle299
Wheels and tires
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Observe the legally required minimum tire tread
depth (Ypage 288). Winter tires can reduce the
braking distance on snow-covered surfaces in
comparison with summer tires. The braking dis-
tance is still much further than on surfaces that
are not icy or covered with snow. Take appro-
priate care when driving.
Further information on winter tires (M+S tires)
(
Ypage 289).
Temperature
GWARNING
The temperature grade for this tire is estab-
lished for atire that is properly inflated and
not overloaded.E xcessive speed, underinfla-
tion, 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, representing the tire's resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions
on aspecified 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 Ccorresponds to alevel of
performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety
Standard No. 109. Grades BandArepresent
higher levels of performance on the laboratory
test wheel than the minimum required by law.
Tire labeling
Overview
:Uniform Tire Quality Grading Standards
(Ypage 306)
;Department of Transportation, Tire Identifi-
cation Number (Ypage 305)
=Maximum load rating (Ypage 304)
?Maximum tire pressures (Ypage 293)
AManufacturer
BTire material (Ypage 305)
CTire size designation, load-bearing capacity
and speed rating (Ypage 302)
DLoad index (Ypage 304)
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 ar isk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
302All about wheels and tires
Wheels and tires

tire load rating and speedrating required for
your vehicle.
:Tire width
;Nomina laspec tratio in %
=Tire code
?Rimd iame ter
ALoadb earing index
BSpeed rating
General: depending on the manufacturer's
standards ,the size imprinted in the tire wall may
not contain any letters or mayc ontain one letter
thatp recedes the size description.
If there is no letter preceding the size descrip-
tio n(as shown above): these ar epassenger
vehicl etiresa ccording to Europea nmanufac-
turing standards.
If "P "precedes the size description: these are
passenge rvehicl etiresa ccording to U.S. man-
ufacturin gstandards.
If "LT" precedes the size description: these are
light truck tire saccording to U.S. manufacturing
standards.
If "T "precedes the size description: compact
emergency wheels with high tire pressure that
ar eo nlyd esig nedf or temporary us einanemer-
gency.
Tire width: tire width:shows the nominal tire
width in millimeters.
Aspec tratio: aspect ratio ;is the size ratio
between the tire height and 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=specifie sthe tire type.
"R "r epresents radial tires; "D" represents diag-
ona ltire s; "
B" represents diagona
lradial tires.
Optionally ,tire sw itham aximum spee dofover
149 mph (240 km/h )mayhave "ZR" in the size description, depending on the manufacturer
(e.g. 245/40Z
R18).
Rim diameter: rim diameter?is the diameter
of the bead seat, not the diamete rofthe rim
flange .The ri mdiame teriss pecifie din
inches (in).
Load-bearin gind ex: load-bearing index Ais a
numerical cod ethats pecifie sthe maximum
load-bearing capacity of atire.
Do not overload the tire sbyexceeding the
specifie dloa dlimit .The maximu mpermissible
load can be found on the vehicle's Tire and
Loading Informatio nplacard on the B-pillar on
the driver's side (
Ypage 298).
Example:
Load-bearin gindex 91 indicates amaximum
load of 1,356 lb (61 5kg)thatt he tire scan bear.
For furtheri nformation on the maximum tire
load in kilograms and lbs, see(
Ypage 304).
For furtheri nformation on the load bearing
index, see" Loadindex" (
Ypage 304).
Speed rating: speedrating Bspecifie sthe
approved maximum spee dofthe tire.
iTire data is vehicle-specific and mayd eviate
fromt he data in the example.
Regardles softhe spee drating ,alway sobser ve
th

e spee dlimit s. Drive carefull yand adap tyou r
drivin gstyle to the trafficc onditions.
Summert ires
IndexSpeed rating
Qup to 100 mph (16 0km/h)
Rup to 106 mph (17 0km/h)
Sup to 112 mph (18 0km/h)
Tup to 118 mph (19 0km/h)
Hup to 130 mph (21 0km/h)
Vup to 149 mph (24 0km/h)
Wup to 168 mph (27 0km/h)
Yup to 186 mph (30 0km/h)
ZR...Yup to 186 mph (30 0km/h)
ZR...(..Y)ove r186 mph (300 km/h)
ZRove r149 mph (240 km/h)
ROptionally ,tire sw itham aximum spee dof
ove r149 mph (24 0km/h )mayhave "ZR" in
Alla bout wheels an dtires303
Wheel sand tires
Z

the size description, depending on the man-
ufacturer (e.g. 245/40ZR18).
The service specification is made up of load-
bearing index Aand spee drating B.
RIf the size description of your tire includes
"ZR" and there ar enoservice specifications,
as kt he tire manufacturer in order to fin dout
the maximum speed.
If as ervice specification is available, the max-
imum spee dislimited according to the speed
rating in the service specification. Example:
245/40Z R1897Y.Int his example," 97 Y" is
the service specification. The letter "Y" rep-
resents the speed rating. The maximum
speed of the tire is limited to 186 mph
(300 km/h).
RThe size descriptionf or all tires with maxi-
mum speedsofo ver 186 mph (300 km/h)
must include "ZR" andthe service specifica-
tion must be given in parentheses.E xample:
275/40 ZR 18 (99 Y) .Speed rating "(Y)" indi-
cates that the maximum speed of the tire is
over 186 mph (300 km/h). Ask the tire man-
ufacturer aboutt he maximum speed.
All-weather tires and winter tires
IndexSpeed rating
QM +S1up to 100 mph (160 km/h)
TM+S1up to 118 mph (190 km/h)
HM +S1up to 130 mph (210 km/h)
VM+S1up to 149 mph (240 km/h)
iNot all tires with the M+S marking provide
the driving characteristics of winter tires. In
addition to the M+S marking, winter tires also
have the isnowflake symbo lonthe tire
wall. Tires with this marking fulfill the require-
ments of the Rubber Manufacturers Associa-
tion (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 you rvehi-
cle from exceeding aspeed of 130 mph
(210 km/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 you
rtires have the required
speed rating, e.g. when buying new tires. The
required speed rating for you rvehicle can be
found in the "Tires" section (
Ypage 312).
Further information aboutr eading tire data can
be obtained from any qualifieds pecialist work-
shop.
Load index
In addition to the load-bearing index, load
index :may be imprinted after the letters that
identify speed rating on the sidewall of the tire.
Speed rating (
Ypage 302).
RIf no specification is given: no text (as in the
example above), represents astandard load
(SL) tire
RXL or ExtraL oad: represents areinforced tire
RLight Load: represents alightl oad tire
RC, D, E: represents aload range that depends
on the maximum load that the tire can carry at
ac ertain pressure
iTire data is vehicle-specific and may deviate
from the data in the example.
Maximum load rating
1Or M+S ifor winter tires.
304Allabout wheels and tires
Wheelsa nd tires

Maximum tire load: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 (
Ypage 298).
iThe 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 aTIN in or on
the sidewall of each tire produced.
The TIN is aunique 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 ;,tire size =,tire type code ?and
manufacturing date A.
DOT (Department of Transportation): tire
symbol :marks that the tire complies with the
requirements of the U.S. DepartmentofT rans-
portation.
Manufacturer identification code: manufac-
turer identification code ;provides details on
the tire manufacturer. New tires have acode
with two symbols. Retreaded tires have acode
with four symbols.
For further information about retreaded tires,
see (
Ypage 312).
Tire size: identifier=describes the tire size.
Tire type code: tire type code?can be used by
the manufacturer as acode to describe specific
characteristics of the tire. Date of manufacture:
date of manufactureA
provides information about the age of atire. The
first and second positions represent the week of
manufacture, startin gwith "01" for the first cal-
endar week. Positions three and four represent
the year of manufacture. For example, atire that
is marked with "3208", was manufactured in
week 32 in 2008.
iTire data is vehicle-specific and may deviate
from the data in the example.
Tire characteristics
This information describes the type of tire cord
and the number of layers in sidewall :and
under tire tread ;.
iTire data is vehicle-specific and may deviate
from the data in the example.
Definition of termsf or tires and loading
Tire ply composition and material used
Describes the number of plies or the number of
layers of rubber-coated fabric in the tire tread
and sidewall. These are made of steel, nylon,
polyester and other materials.
Bar
Metric unit for tire pressure. 14.5038 pounds
per square inch (psi) and 100 kilopascals (kPa)
are the equivalent of1bar.
DOT (Department of Transportation)
DOT-marked tires fulfill the requirements of the
USD epartmen tofTransportation.
Normal occupant weight
The number of occupants for which the vehicle
is designed multiplied by 68 kilograms (150 lbs).
All about wheels and tires305
Wheels and tires
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PSI (pounds per squareinch)
Astandard 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:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been driven further than
1m ile (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.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, aroof rack or ahigh-per-
formanceb attery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is aunique identifier which can be used by
at ire manufacturer to identify tires, for example
for aproduct recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date.
Load bearing index
The load bearing index (also load index) is acode
that contains the maximum load bearing capa-
city of atire.
Traction
Traction is the result of friction between the tires
and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of áin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in avehicle at their
designated seating positions.
Total load limit
Nominal load and luggage load plus 68 kg
(15 0lbs)m ultiplied by the number of seats in
the vehicle.
Changing awheel
Flat tire
The "Breakdown assistance" section
(Ypage 271) contains information and notes on
how to deal with aflat tire. Information on driv-
ing with MOExtended tires in the event of aflat
tire can be found under "MOExtended tires (tires
with run-flat characteristics" (
Ypage 271).
Rotating the wheels
GWARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is arisk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
!On vehicles equippedw ithatire pressure
monitor ,electronic components are located
in the wheel.
Changing awheel307
Wheels and tires
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