2013 MERCEDES-BENZ SL-CLASS ROADSTER warning

All about wheels and tires
Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards Uniform Tire Quality Grading Standards are
U.S. government specifications. Their
purpose is to provide drivers with uniform
reliable
information
on tire performance data.
Tire manufacturers have to grade tires using
three performance factors: treadwear
grade :, traction grade ; and temperature
grade =. These regulations do not apply to
Canada. Nevertheless, all tires sold in North
America are provided with the corresponding
quality grading markings on the sidewall of
the tire.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
Example:
R Treadwear grade: 200
R Traction grade: AA
R Temperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. 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,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics 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,
cornering, hydroplaning, or peak traction
characteristics.
! Avoid wheelspin.

This can lead to damage
to the drive train.
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
surfaces.
You should pay special attention to road
conditions when temperatures are around
freezing point.
Mercedes-Benz recommends a minimum
tread depth of ã in (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (Y page 527). Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
The braking distance is still much further than 540
All about wheels and tires
Wheels and tires

on surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (Y page 528).
Temperature
G
WARNING
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, 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. These represent the tire's
resistance to the generation of heat 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 grade C corresponds 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 :
Uniform Tire Quality Grading Standard
(Y page 545)
; DOT, Tire Identification Number
(Y page 544)
= Maximum tire load ( Y page 544)
? Maximum tire pressure (Y page 532)
A Manufacturer
B Tire material ( Y page 545)
C Tire size designation, load-bearing
capacity and speed index (
Y

page 541)
D Load index ( Y page 544)
E Tire name
The markings described above are on the tire
in addition to the tire name (sales
designation) and the manufacturer's name.
i Tire data is vehicle-specific and may
deviate from the data in the example.
Tire size designation, load-bearing
capacity and speed rating G
WARNING
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. All about wheels and tires
541
Wheels and tires
Z

Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward
force
to each square inch of the tire's
surface. 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 without
direct sunlight on the tires for at least three
hours and
R if the vehicle has been driven for less 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 kilograms (5 lbs).
These optional extras, such as high-
performance brakes, level control, a roof rack
or a high-performance 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 purchasers. The TIN is made up of the
manufacturer'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
capacity 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
distributed over the tire tread. If the tire tread
is level with the bars, the wear limit of á in
(1.6 mm) has been reached.
Occupant distribution
The distribution of occupants in a vehicle at
their designated seating positions.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lb) multiplied by the
number of seats in the vehicle. Changing a wheel
Flat tire
Information on the procedure in the event of
a flat tire ( Y page 509). You will also find
information on

driving with MOExtended tires
in the event of a flat tire. Interchanging the wheels
G
WARNING
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 a risk of
accident. Changing a wheel
547
Wheels and tires
Z

Rotate front and rear wheels only if the wheels
and tires are of the same dimensions.
! On vehicles

equipped with a tire pressure
monitor, electronic components are
located in the wheel.
Tire-mounting tools should not be used
near the valve. This could damage the
electronic components.
Only have tires changed at a qualified
specialist workshop.
Always pay attention to the instructions and
safety notes when changing a wheel
(Y page 548).
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.
If your vehicle's tire configuration allows, you
can rotate the wheels according to the
intervals in the tire manufacturer's warranty
book in your vehicle documents. If this is not
available, the tires should then be replaced
every 3000 to 6000 miles (5000 to
10,000 km), or earlier if the tire wear requires
this. 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 interchanged. Check the tire pressure and,
if necessary, restart the tire pressure loss
warning system or the tire pressure monitor. Direction of rotation
Tires with a specified direction of rotation
have additional

benefits, e.g. if there is a risk
of hydroplaning. You will only gain these
benefits if the correct direction of rotation is
maintained.
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. Cleaning the wheels
G
WARNING
Do not use power washers with circular-jet
nozzles (dirt

grinders) to clean your vehicle, in
particular the tires. You could otherwise
damage the tires and cause an accident. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Unload the vehicle. The jack can only be
used when the vehicle is unladen.
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: open the
driver's door.
The on-board electronics have status 0,
which is the same as the SmartKey having
been removed.
X Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
(Y page 135).
X If included in the vehicle equipment,
remove the tire-change tool kit from the
vehicle.
X Secure the vehicle to prevent it from rolling
away.548
Changing a wheel
Wheels and tires

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 508).
The folding wheel chock is an additional
securing
measure
to prevent the vehicle from
rolling away, for example when changing a
wheel.
X Fold both plates upwards :.
X Fold out lower plate ;.
X Guide the lugs on the lower plate fully into
the openings in base plate =.Securing the vehicle on level ground
X
On level ground: place chocks or other
suitable items under the front and rear of
the wheel that is diagonally opposite the
wheel you wish to change. Securing the vehicle on slight downhill gradients
X
On light downhill gradients: place
chocks or other suitable items in front of
the wheels of the front and rear axle.
Raising the vehicle G
WARNING
If you do not position the jack correctly at the
appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate
jacking point of the vehicle. The base of the
jack must be positioned vertically, directly
under the jacking point of the vehicle.
! The jack is designed exclusively for
jacking up

the vehicle at the jacking points.
Otherwise, your vehicle could be damaged.
The following must be observed when raising
the vehicle:
R to raise the vehicle, only use the vehicle-
specific jack that has been tested and
approved by Mercedes-Benz. If used
incorrectly, the jack could tip over with the
vehicle raised.
R the jack is designed only to raise and hold
the vehicle for a short time while a wheel
is being changed. It is not suited for
performing maintenance work under the
vehicle.
R avoid changing the wheel on uphill and
downhill slopes. Changing a wheel
549
Wheels and tires Z

=
Jacking points
? Jack
A Crank
X Position jack ? at jacking point =.Example
X
Make sure the foot of the jack is directly
beneath the jacking point.
X Turn crank A clockwise until jack ? sits
completely on jacking point = and the
base of the jack lies evenly on the ground.
X Turn crank A until the tire is raised a
maximum of 1.2 in (3 cm ) off the ground.
Removing a wheel !
AMG vehicles: during removal and
repositioning of the wheel, the wheel rim
can strike the ceramic-brake disc and
damage it.
Therefore, take precautions and
get a second person to assist you.
Alternatively, you can use a second
alignment bolt. !
Do not place wheel bolts in sand or on a
dirty surface. The bolt and wheel hub
threads could

otherwise be damaged when
you screw them in. X
Unscrew the uppermost wheel bolt
completely.
X Screw alignment bolt : into the thread
instead of the wheel bolt.
X Unscrew the remaining wheel bolts fully.
X Remove the wheel.
Mounting a new wheel G
WARNING
Oiled or greased wheel bolts or damaged
wheel bolts/hub

threads can cause the wheel
bolts to come loose. As a result, you could
lose a wheel while driving. There is a risk of
accident.
Never oil or grease wheel bolts. In the event
of damage to the threads, contact a qualified
specialist workshop immediately. Have the
damaged wheel bolts or hub threads
replaced/renewed. Do not continue driving. G
WARNING
If you tighten the wheel bolts or wheel nuts
when the vehicle is raised, the jack could tip
over. There is a risk of injury.
Only tighten the wheel bolts or wheel nuts
when the vehicle is on the ground.
Always pay attention to the instructions and
safety notices in "Changing a wheel"
(Y page 547). Changing a wheel
551
Wheels and tires Z

Only use wheel bolts that have been designed
for the wheel and the vehicle. For safety
reasons, Mercedes-Benz recommends that
you only use wheel bolts which have been
approved
for
Mercedes-Benz vehicles and the
respective wheel.
! AMG vehicles: during removal and
repositioning of the wheel, the wheel rim
can strike the ceramic-brake disc and
damage it. Therefore, take precautions and
get a second person to assist you.
Alternatively, you can use a second
alignment bolt.
! To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt. X
Clean the wheel and wheel hub contact
surfaces.
X Slide the wheel to be mounted onto the
alignment bolt and push it on.
X Tighten the wheel bolts until they are
finger-tight.
X Unscrew the alignment bolt.
X Tighten the last wheel bolt until it is finger-
tight.
Lowering the vehicle G
WARNING
The wheels could work loose if the wheel nuts
and bolts are not tightened to the specified
tightening torque. There is a risk of accident. Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel is changed.
X
Turn the crank of the jack counter-
clockwise until the vehicle is once again
standing firmly on the ground.
X Place the jack to one side.
X Tighten the wheel bolts evenly in a
crosswise pattern in the sequence
indicated ( : to A). The specified
tightening torque is 96 lb-ft(130 Nm).
X Turn the jack back to its initial position.
X Stow the jack and the rest of the vehicle
tools in the trunk again.
X AMG vehicles and vehicles with AMG
equipment: insert

the cover into the outer
sill.
X Check the tire pressure of the newly
mounted wheel and adjust it if necessary.
Make sure to observe the recommended
tire pressure ( Y page 529).
i Vehicles with tire pressure monitor: all
wheels mounted must be equipped with
functioning sensors. Wheel and tire combinations
General notes
! For safety reasons, Mercedes-Benz
recommends that you only use tires and
wheels which have been approved by
Mercedes-Benz specifically for your
vehicle. 552
Wheel and tire combinationsWheels and tires

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please
note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 31).Information regarding technical data
i The data

stated here specifically refers to
a vehicle with standard equipment. Consult
a Mercedes-Benz Center for the data for all
vehicle variants and trim levels. Genuine Mercedes-Benz parts
G
WARNING
Driving safety may be impaired if non-
approved parts, tires and wheels or safety-
relevant accessories are used.
This could lead to malfunctions in safety-
relevant systems,

e.g. the brake system. This
could cause you to lose control of your vehicle
and cause an accident.
For this reason, Mercedes-Benz recommends
that you use genuine Mercedes-Benz parts or
parts of equal quality. Only use tires, wheels
and accessories that have been specifically
approved for your vehicle. H
Environmental note
Daimler
AG also supplies reconditioned major
assemblies and parts which are of the same
quality as

new parts. They are covered by the
same Limited Warranty entitlements as new
parts. !
Air bags and Emergency Tensioning
Devices, as well as control units and
sensors for

these restraint systems, may be
installed in the following areas of your
vehicle:
R doors
R door pillars
R door sills
R seats
R cockpit
R instrument cluster
R center console
Do not install accessories such as audio
systems in these areas. Do not carry out
repairs or welding. You could impair the
operating efficiency of the restraint
systems.
Have aftermarket accessories installed at
a qualified specialist workshop.
Genuine Mercedes-Benz parts are subject to
strict quality control. Each part has been
specially developed, manufactured or
selected for Mercedes-Benz vehicles and
fine-tuned for them. Only genuine Mercedes-
Benz parts should therefore be used.
More than 300,000 different genuine
Mercedes-Benz parts are available for
Mercedes-Benz models.
All Mercedes-Benz Centers maintain a supply
of genuine Mercedes-Benz parts for
necessary service and repair work. In
addition, strategically located parts delivery
centers provide quick and reliable parts
service.
Always specify the vehicle identification
number (VIN) ( Y page 559) and the engine
number (Y page 560) when ordering
genuine Mercedes-Benz parts. Warranty
Your vehicle

is covered under the terms of the
warranties printed in the Service and
Warranty Information booklet. 558
Warranty
Technical data