tires MERCEDES-BENZ CLA 2017 Service Manual

Uniform Tire Quality Grading Standards A uniform standard to grade the quality of tires
with regards to tread quality, tire traction and
temperature characteristics. The quality grad-
ing assessment is made by the manufacturer
following specifications from the U.S. govern-
ment. The ratings are molded into the sidewall of
the tire.
Recommended tire pressures The recommended tire pressure applies to the
tires mounted at the factory.
The Tire and Loading Information placard con-
tains the recommended tire pressures for cold
tires on a fully loaded vehicle and for the maxi-
mum permissible vehicle speed.
The tire pressure table contains the recommen-
ded pressures for cold tires for various operat-
ing conditions, i.e. differing load and speed con-
ditions.
Increased vehicle weight due to optional
equipment The combined weight of all standard and
optional equipment available for the vehicle,
regardless of whether it is actually installed on
the vehicle or not.
Rim This is the part of the wheel on which the tire is
mounted.
GAWR (Gross Axle Weight Rating) The GAWR is the maximum gross axle weight
rating. The actual load on an axle must never
exceed the gross axle weight rating. The gross
axle weight rating can be found on the vehicle
identification plate on the B-pillar on the driver's
side.
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 n oseweight, 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.300
All about wheels and tires
Wheels and tires

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.
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, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example
for a product 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 a code
that contains the maximum load bearing capa-
city of a tire.
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

Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Observe the instructions and safety notes in the
"Changing a wheel" section ( Y
page 301).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in
the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Depending on tire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system
(Canada only) or the tire pressure monitor (USA
only).
Direction of rotation Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correct direction of rotation.
Storing wheels Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground. X
Apply the electric parking brake manually. X
Bring the front wheels into the straight-ahead
position. X
Shift the transmission to position P .X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO start-function
or KEYLESS-GO: open the driver's door.
The vehicle electronics now have status 0 .
This is the same as the SmartKey having been
removed. X
Vehicles with KEYLESS-GO start-function
or KEYLESS-GO: remove the Start/Stop but-
ton from the ignition lock ( Y
page 121).X
Make sure that the engine cannot be started
via your smartphone ( Y
page 122).X
If included in the vehicle equipment, remove
the tire-change tool kit from the vehicle. X
Safeguard the vehicle against rolling away
( Y
page 140).
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
( Y
page 266).
The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away, for example when changing a wheel.302
Changing a wheel
Wheels and tires

Wheel and tire combinations
General notes You can ask for information regarding permitted
wheel/tire combinations at an authorized
Mercedes-Benz Center.
You should regularly check the pressure of the
emergency spare wheel, particularly prior to
long trips, and correct the pressure as neces-
sary ( Y
page 285). The value on the wheel is
valid.
! For safety reasons, Mercedes-Benz recom-
mends that you only use tires and wheels
which have been approved by Mercedes-Benz
specifically for your vehicle.
These tires have been specially adapted for
use with the control systems, such as ABS or
ESP ®
, and are marked as follows: R
MO = Mercedes-Benz Original R
MOE = Mercedes-Benz Original Extended
(tires featuring run-flat characteristics) R
MO1 = Mercedes-Benz Original (only cer-
tain AMG tires)
Mercedes-Benz Original Extended tires may
only be used on wheels that have been spe-
cifically approved by Mercedes-Benz.
Only use tires, wheels or accessories tested
and approved by Mercedes-Benz. Certain
characteristics, e.g. handling, vehicle noise
emissions or fuel consumption, may other-
wise be adversely affected. In addition, when
driving with a load, tire dimension variations
could cause the tires to come into contact
with the bodywork and axle components. This
could result in damage to the tires or the vehi-
cle.
Mercedes-Benz accepts no liability for dam-
age resulting from the use of tires, wheels or
accessories other than those tested and
approved.
Information on tires, wheels and approved
combinations can be obtained from any quali-
fied specialist workshop.
! Retreaded tires are neither tested nor rec-
ommended by Mercedes-Benz, since previ-
ous damage cannot always be detected on
retreaded tires. As a result, Mercedes-Benz
cannot guarantee vehicle safety if retreaded
tires are mounted. Do not mount used tires if
you have no informa tion a bout their previous
u
sage. The recommended pressures for various oper-
ating conditions can be found: R
on the Tire and Loading Information placard
on the B-pillar on the driver's side R
in the tire pressure table in the fuel filler flap
Observe the notes on recommended tire pres-
sures under various operating conditions
( Y
page 285).
Check tire pressures regularly, and only when
the tires are cold. Comply with the maintenance
recommendations of the tire manufacturer in
the vehicle document wallet.
Notes on the vehicle equipment – always equip
the vehicle: R
with tires of the same size on a given axle (left
and right) R
with the same type of tire (summer tires,
MOExtended tires, winter tires)
Exception: it is permissible to install a differ-
ent type or make in the event of a flat tire.
Observe the "MOExtended tires (tires with
run-flat characteristics" section ( Y
page 267).
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory. It
is therefore recommended that you additionally
equip your vehicle with a TIREFIT kit if you mount
tires that do not feature run-flat properties, e.g.
winter tires. A TIREFIT kit may be obtained from
a qualified specialist workshop.306
Wheel and tire combinations
Wheels and tires