MERCEDES-BENZ SLK250 2012 R172 Owner's Manual

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

Checking tire pressure electronically
X
Make sure that the SmartKey is in
position 2(Ypage 131) in the ignition lock.
X Press the 0002or0005 button on the
steering wheel to selec tthe Service menu.
X Press the 0003or0004 button to select
Tire Pressure .
X Press the 000Cbutton.
The current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle has been parked for longer than
20minutes, the Tire pressure will be displayed after driving a few
minutes message appears.
After a teach-in period, the tire pressure
monitor automatically recognizes new wheels
or new sensors. As long as a clear allocation
of the tire pressure values to the individual
wheels is not possible, the Tire PressureMonitor Active display message is shown
instead of the tire pressure display. The tire
pressures are already being monitored.
i If a spare wheel/emergency spare wheel
is mounted, the system may continue to
show the tire pressure of the wheel that has
been removed for a few minutes. If this
occurs, note that the value displayed for
the position where the spare tire is
mounted is not the same as the spare
wheel/emergency spare wheel's current
tire pressure.
Tire pressure monitor warning
messages If the tire pressure monitor detects a
significant pressure loss on one or more tires,
a warning message is shown in the
multifunction display. Awarning tone also
sounds and the tire pressure warning lamp
lights up in the instrumen tcluster.
Each tire that is affected by a significant loss
of pressure is highlighted with a color. If the
Correct tire pressure message
appears in the multifunction display:
X Check the tire pressure on all four wheels
and correct it if necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
shor ttime. This is rectified after a few
minutes of driving, and the tire pressures
are displayed for the correc tpositions.
Restarting the tire pressure monitor When you restart the tire pressure monitor,
all existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the
reference values for monitoring. In most
cases, the tire pressure monitoring system
recognizes the new reference values
automatically.
However, you can also define reference
values manually as described here:
X
Set the tire pressure to the value
recommended for the corresponding
driving situation on the vehicle's Tire and
Loading Information placard on the driver's
side B-pillar(Y page 297).
Additional tire pressure values for driving
at high speeds or with heavy loads can be
found in the tire pressure table on the
inside of the fuel filler flap.
X Make sure that the tire pressure is correct
on all four wheels.
X Make sure that the SmartKey is in position
2 in the ignition lock.
X Press the 0002or0005 button on the
steering wheel to select the Service menu.
X Press the 0003or0004 button to select
Tire Pressure .
X Press the 000Cbutton.
The multifunction display shows the
current tire pressure of the individual tires
or the Tire pressure will be Tire pressure
303Wheels and tires Z

displayed after driving a few
minutes message.
X Press the 0004button.
The Use Current Pressures as New Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
X Press the 000Cbutton.
The Tire 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:
X Press the 0001button.
The tire pressure values stored at the last
restart will continue to be monitored. Loading the vehicle
Instruction labels for tires and loads
G
WARNING
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.
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
installed 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 aboutt he
maximum gross axle weight rating on the
front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried
by one axle (front or rear axle). Never
exceed the maximum load or the
maximum gross axle weight rating for the
front or rear axle. 0002
B-pillar, driver's side Maximum permissible load
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The maximum
permissible load is vehicle-specific and
may deviate from the data shown here. The
maximum permissible load that applies for
your vehicle can be found on your vehicle's
Tire and Loading Information placard. 304
Loading the vehicleWheels and tires

X
Specification for maximum permissible
load 0002is listed on the Tire and Loading
Information placard: "The gross weight of
occupants and luggage mus tnot exceed
XXX kg or XXX lbs."
The gross weight of all vehicle occupants,
load, luggage and trailer load/noseweight (if
applicable) must not exceed the specified
value. Number of seats
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The number of
seats is vehicle-specific and can differ from
the details shown. The number of seats in
your vehicle can be found on the Tire and
Loading Information placard. Maximum number of seats
0002determines the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Information
placard. Determining the correct load limit
Step-by-step instructions The following steps have been developed as
required of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part 575
pursuant to the "National Traffic and Motor
Vehicle Safety Act of 1966".
X
Step 1: Locate the statement "The
combined weight of occupant sand cargo
should neve rexceed XXX kg or XXX lbs." on
your vehicle’s Tire and Loading Information
placard.
X Ste p2:Determine the combined weight of
the driver and passengers tha twill be riding
in your vehicle.
X Step 3: Subtract the combined weight of
the drive rand passengers from XXX
kilograms or XXX lbs.
X Ste p4:The resulting figure equals the
available amount of cargo and luggage load
capacity. For example, if the "XXX" amount
equals 1400 lbs and there will be five 150
lbs passengers in your vehicle, the amount
of available cargo and luggage load
capacity is 650 lbs (1 400 - 750 (5 x 150)
= 650 lbs).
X Step 5: Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely exceed
the available cargo and luggage load
capacity calculated in step 4.
X Step 6 (if applicable): If your vehicle will
be towing a trailer, load from your trailer
will be transferred to your vehicle. Consult
this manual to determine how this reduces
the available cargo and luggage load
capacity of your vehicle ( Ypage 307). Loading the vehicle
305Wheels 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 load limit of 1500 lbs (680 kg). This is for illustration purposes only. Make sure you are
using the actual load limit for you rvehicle stated on your vehicle's Tire and Loading Information
placard (Y page 305). Example 1 Example 2
Step 1 Combined maximum
weight of occupants and
cargo (data from the Tire
and Loading Information
placard)
1500 lbs (680 kg) 1500 lbs (680 kg)
Example 1 Example 2
Step 2 Number of people in the
vehicle (driver and
occupants)
1 2
Weight of the occupants
Occupant 1: 175 lbs
(80 kg) Occupant 1: 175 lbs
(80 kg)
Occupant 2: 195 lbs)
(88 kg
Gross weight of all
occupants
175 lbs (80 kg) 370 lbs (168 kg)
Example 1 Example 2
Step 3 Permissible load and
trailer load/noseweight
(maximum permissible
load rating from the Tire
and Loading Information
placard minus the gross
weight of all occupants)
1500 lbs (680 kg) -
175 lbs (80 kg) =
1325 lbs (600 kg) 1500 lbs (680 kg) -
370 lbs (168 kg) =
1130 lbs (512 kg)
The higher the weight of all the occupants, the smaller the maximum load for luggage.
Further information can be found under "Towing atrailer" (Y page 307). Vehicle identification plate
Even if you have calculated the total load
carefully, you should still make sure that the
gross vehicle weight rating and the gross axle weight rating are not exceeded. Details can
be found on the vehicle identification plate on
the B-pillar on the driver's side of the vehicle
(Y page 304). 306
Loading the vehicleWheels and tires

Permissible gross vehicle weight:
the
gross weight of the vehicle, all passengers,
load and trailer load/noseweight (if
applicable) must not exceed the permissible
gross vehicle weight.
Gross axle weight rating: the maximum
permissible weight that can be carried by one
axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross
vehicle weight and maximum gross axle
weight rating), have your loaded vehicle
(including driver, occupants, cargo, and full
trailer load if applicable) weighed on a
suitable vehicle weighbridge. Trailer load/noseweight
The trailer load/noseweight affects the gross
weight of the vehicle. If a trailer is attached,
the trailer load/noseweight is included in the
load along with occupants and luggage. The
trailer load/noseweight is usually
approximately 10% of the gross weight of the
trailer and its load.
Your Mercedes-Benz has been designed
primarily to carry passengers and their
luggage. Mercedes-Benz does not
recommend towing a trailer with your vehicle. Maximum load rating
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
(Y page 304). i
The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Maximum tire load 0002is the maximum
permissible weight for which the tire is
approved. 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: tread wear
0002,
tire traction 0003, and heat resistance 0023. All
tires sold in North America are provided with
the corresponding quality class mark on the
sidewall of the tire, even though these
regulations do not apply to Canada. Uniform Tire Quality Grading Standards
307Wheels and tires Z

i
The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
For example: Tread wear Traction Temperature
200 AA A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Tread wear
The tread wear grade is acomparative 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.
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.
Atire 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
the freezing point.
Mercedes-Benz recommends a minimum
tread depth of 000Ain(4 mm) for all four winter
tires (Y page 296) to maintai nnormal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
Stopping distance, however, is still
considerably greater than when the road is
not covered with ice or snow. Take
appropriate care when driving.
! Avoid wheelspin. This can lead to damage
to the drive train. 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 generatio nofheat 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 Ccorresponds 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 308
Uniform Tire Quality Grading StandardsWheels and tires