2012 MERCEDES-BENZ SLK250 Owner's Manual

Notes on regularly inspecting wheels
and tires G
WARNING
Damaged tires can cause tire inflation
pressure loss. As a result, you could lose
control of your vehicle. There is a risk of
accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
R Regularly check the wheels and tires of
your vehicle for damage (e.g. cuts,
punctures, tears, bulges on tires and
deformation or cracks or severe corrosion
on wheels) at leas tonce amonth, as well
as after driving off-road or on rough roads.
Damaged wheels can cause a loss of tire
pressure.
R Regularly check the tire tread depth and
the condition of the tread across the whole
width of the tire (Y page 295). If necessary,
turn the front wheels to full lock in order to
inspect the inner side of the tire surface.
R All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
mount anything onto the valve (such as tire
pressure monitoring systems) other than
the standard valve cap or other valve caps
approved by Mercedes-Benz for your
vehicle.
R Regularly check the pressure of all the tires
including the emergency spare wheel or the
spare wheel, particularly prior to long trips,
and correc tthe pressure as necessary
(Y page 297). Tire tread
G
WARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk
of hydroplaning increases, in particular where
speed is not adapted to suit the driving
conditions. There is a risk of accident. If the tire pressure is too high or too low, tires
may exhibit different levels of wear at
different locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
R
Summer tires: 0009in (3 mm)
R M+S tires: 000Ain (4 mm)
For safety reasons, replace the tires before
the legally prescribed limit for the minimum
tire tread depth is reached.
Tread wear indicators (TWI) are required by
law. Six indicators are positioned on the tire
tread. They are visible once the tread depth
is approximately 0008in (1.6 mm). If this is the
case, the tire is so worn that it must be
replaced. Bar marking
0002for tread wear is integrated
into the tire tread. Notes on selecting, mounting and
replacing tires
R Only mount tires and wheels of the same
type and make.
R Only mount tires of the correct size onto
the wheels.
R After mounting new tires, run them in at
moderate speeds for the first 60 miles
(100 km) as they only reach their full
performance after this distance. Operation
295Wheels and tires Z

R
Do not drive with tires which have too little
tread depth, as this significantly reduces
the tractio nonwet roads (hydroplaning).
R Replace the tires after six years at the
latest, regardless of wear. This also applies
to the spare wheel/emergency spare
wheel.
The service life of tires depends on the
following factors amongst other things:
R driving style
R tire pressure
R distance covered MOExtended tires (tires with run-flat
properties)
MOExtended tires (tires with run-flat
properties) allow you to continue driving your
vehicle even if one or more tires are entirely
deflated.
MOExtended tires may be used only in
conjunction with the activated tire pressure
loss warning system or the activated tire
pressure monitoring system and only on
wheels specifically tested by Mercedes-Benz.
Notes on driving with MOExtended tires in the
event of a flat tire can be found in the
"Breakdown assistance" section
(Y page 281). Winter operation
Please bear the following in mind
Have your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section (Y page 315). Driving with summer tires
At temperatures below 45 ‡ (+7 †), the
elasticity of summer tires and therefore also
the traction and brakin gcapability are
reduced considerably. Moun tM+S tires on you
rvehicle. Using summer tires at very cold
temperatures could cause cracks to form,
thereby damaging the tires permanently.
Mercedes-Benzc annot accept responsibility
for this type of damage. M+S tires
At temperatures below 45 ‡ (+7 †), use
winter tires or all-season tires. Both types of
tire are identified by th eM+S marking.
Only winter tires bearing the 0003snowflake
symbol in addition to the M+S marking
provide the best possible grip in wintry road
conditions. Only these tires will allow driving
safety systems such as ABS and ESP ®
to
function optimally in winter. These tires have
bee ndeveloped specifically for driving in
snow.
Use M+S tires of the same make and tread on
all wheels to maintain safe handling
characteristics. G
WARNING
M+S tires with a tire tread depth of less than
000A in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There
is a risk of an accident.
M+S tires with a tread depth of less than 000A
in (4 mm) must be replaced immediately.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
When you have mounted M+S tires:
X Check the tire pressures (Y page 301).
X Vehicles for USA: restart the tire pressure
monitor (Y page 301).
Drive no faster than 50 mph (80 km/h) with
the spare wheel or emergency spare wheel
mounted. G
WARNING
The wheel or tire size as well as the tire type
of the spare wheel or emergency spare wheel
and the wheel to be replaced may differ. 296
Winter operationWheels and tires

Mounting an emergency spare wheel may
severely impair the driving characteristics.
There is a risk of an accident.
To avoid hazardous situations:
R
adapt your driving style accordingly and
drive carefully.
R never install more than one spare wheel or
emergency spare wheel that differs in size.
R only use a spare wheel or emergency spare
wheel of a different size briefly.
R do not switch ESP ®
off.
R have a spare wheel or emergency spare
wheel of a different size replaced at the
nearest qualified specialist workshop.
Observe that the wheel and tire dimensions
as well as the tire type must be correct. Snow chains
For safety reasons, Mercedes-Benz
recommends that you only use snow chains
that have been specially approved for your
vehicle by Mercedes-Benz, or are of a
corresponding standard of quality.
! On some tire sizes there is not enough
space for snow chains. To avoid damage to
the vehicle or tires, observe the "Wheel and
tire combinations" section under "Tires and
wheels".
R only use snow chains when driving on roads
completely covered by snow. Do not
exceed the maximum permissible speed of
30 mph (50 km/h). Remove the snow
chains as soon as possible if you are driving
on roads that are no longer snow-covered.
R local regulations may restrict the use of
snow chains. Observe the appropriate
regulations if you wish to mount snow
chains.
R snow chains may not be mounted on the
emergency spare wheel. If you intend to mount snow chains, please
bear the following points in mind:
R
snow chains may not be mounted on all
wheel/tire combinations. Permitted
wheel/tire combinations (Y page 316).
R mount snow chains only in pairs and only
on the rear wheels. Observe the
manufacturer's mounting instructions.
! If snow chains are mounted on the front
wheels, the snow chains could grind
against the bodywork or components of the
chassis. This could result in damage to the
vehicle or the tires.
! Vehicles with steel wheels: if you wish
to mount snow chains on steel wheels,
make sure that you remove the respective
wheels' hubcaps first. The hubcaps may
otherwise be damaged.
i You may wish to deactivate
ESP ®
(Y page 58) when pulling away with
snow chains mounted. This way you can
allow the wheels to spin in a controlled
manner, achieving an increased driving
force (cutting action). Tire pressure
Tire pressure specifications
G
WARNING
Tires with tire pressures that are too low or
too high are associated with the following
hazards:
R they can burst, in particular if the vehicle is
heavily laden or when driven at high
speeds.
R the tires can wear excessively and/or
unevenly, which can severely impair tire
traction.
R the driving, steering and braking
characteristics may be severely impaired.
There is a risk of accident. Tire pressure
297Wheels and tires
Z

Follow recommended tire inflation pressures
and check the pressure of all the tires
including the spare wheel:
R
monthly, at least
R if the load changes
R before beginning a long journey
R under different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
The recommended tire pressures for the tires
mounted at the factory can be found on the
labels described here.
Option 1) Tire and Loading Information
placard on the B-pilla ronthe driver's side of
the vehicle (Y page 304).
The Tire and Loading Information placard
contains the recommended tire pressures for
cold tires on a fully loaded vehicle and for the
maximum permissible vehicle speed.
i The specifications given on the following
Tire and Loading Information placard are
examples. Tire pressure specifications are
vehicle-specific and may deviate from the
data shown here. The tire pressures
applicable to your vehicle can be found on
the Tire and Loading Information placard on
your vehicle. 0002
Recommended tire pressures
Option 2) Tire pressure table on 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.
i
Specifications 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 permitted
for 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.
Example: tire pressure table with tire dimensions
Some tire pressure tables show only the rim
diameters instead of the full tire size, e.g.
R18. The rim diameter is part of the tire size298
Tire pressureWheels and tires

and can be found on th
etire sidewall
(Y page 309). 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.
Option 3) The tire pressure for the
emergency/collapsible spare wheel
(depending on vehicle equipment) can be
found:
R printed in yellow on the rim of the
emergency/collapsible spare wheel
R in the "Wheel and tire combinations"
section (Y page 316) in this Operator's
Manual
R on the Tire and Loading Information placard
on the B-pillar on the driver's side.
If the tire pressure is not set correctly, this
can lead to an excessiv ebuild up of heat and
a sudde nloss of pressure.
For more information, contact a qualified
specialist 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,
contact 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
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.
To test tire pressure, use a suitable tire
pressure gauge. The outer appearance of a
tire does not permit any reliable conclusion
about the tire pressure. On vehicles equipped
with the electronic tire pressure monitoring
system, the tire pressure can be checked
using the on-board computer.
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:
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 Tire pressure
299Wheels and tires Z

changes by 18 ‡ (10 †), the tire pressure
changes by approximately 10 kPa (0.1 bar/
1.5 psi). Take this into account when
checking the pressure of warm tires and only
correct the tire pressure if it is too low for the
current operating conditions
.Ifyou check the
tire pressure when the tires are warm, the
resulting 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-pillar on the driver's side
R in the tire pressure table on the inside of
the fuel filler flap
R printed in yellow on the rim of the
emergency/collapsible spare wheel
(depending on vehicle equipment) Underinflated or overinflated tires
Underinflation G
WARNING
Tires with pressure that is too low can
overheat and burst as a consequence. In
addition, they also suffer from excessive and/
or 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 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
characteristics 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
characteristics
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
recommended tire pressure for your vehicle
when adjusting the tire pressure
(Y
page 297). 0002
Example: maximum permissible tire
pressure
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. 300
Tire pressureWheels and tires

Checking the tire pressures
Important safety notes Observe the "Tire pressure information"
sectio n(Ypage 297).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information 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
pressure, 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
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 297).
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
chec kthe tire pressure again using the tire
pressure gauge.
X Screw the valve cap onto the valve.
X Repeatt hese steps for the other tires. Tire pressure monitor (USA only)
Important safety notes 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 297). Note that the correct tire
pressure 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 adjusting the pressure of the
cold tires (Y page 303). The current
pressures are saved as new reference values.
As a result, a warning message will appearif
the 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
(Y page 297).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g .ifthe
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.
If a tire pressure monitor system 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 to all wheels.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss or amalfunction.
Whether the warning lamp flashes or lights up
indicates whether a tire pressure is too low or
the tire pressure monitoring system is
malfunctioning:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly 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 monito ris malfunctioning. G
WARNING
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 Tire pressure
301Wheels and tires
Z

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
tires are significantly underinflated.
Accordingly, when the low tire pressure
telltale illuminates, you should stop and check
your tires as soon as possible, and inflate
them to the proper pressure. Driving on a
significantly underinflated 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 responsibility to maintain correc ttire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate if the
system is not operating properly. The TPMS
malfunction indicator is combined with the
low tire pressure telltale. When the system
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
vehicle is started as long as the malfunction
exists.
When the malfunction indicator is illuminated,
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
incompatible replacement or alternate tires
or wheels on the vehicle that prevent the
TPMS from functioning properly. 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.
i 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 malfunction has been rectified,
the tire pressure warning lamp goes out
after a few minutes of driving.
Information on tire pressures is displayed in
the multifunction display .After a few minutes
of driving, the current tire pressure of each
tire is show ninthe multifunction display.
i The tire pressure values indicated by the
on-board computer may differ from those
measured 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
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the
tire pressures.
i The operation of the tire pressure monitor
can be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
i This device complies with part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment. 302
Tire pressureWheels and tires