317 Operation
Tires and wheels
Checking tire pressure electronically
with the Tire Pressure Monitoring
System (TPMS), (USA only)
The TPMS only functions on wheels that
are equipped with the proper electronic
sensors. It monitors the tire inflation pres-
sure, as selected by the driver, in all four
tires. A warning is issued to alert you to a
decrease in pressure in one or more of the
tires.
iThe Tire Pressure Monitoring System
(TPMS) is equipped with a combination low tire
pressure/TPMS malfunction telltale in the
instrument cluster (
page 26). Depending on
how the telltale illuminates, it indicates a low tire
pressure condition or a malfunction in the TPMS
system itself:
If the telltale illuminates continuously, one
or more of your tires is significantly underin-
flated. There is no malfunction in the TPMS.
If the telltale flashes for 60 seconds and
then stays illuminated, the TPMS system
itself is not operating properly.
iThis device complies with Part 15 of the
FCC Rules. Operation is subject to the following
two conditions:
(1) This device may not cause harmful interfer-
ence, and
(2) this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.Warning!G
The TPMS does not indicate a warning for
wrongly selected inflation pressures. Always
adjust tire inflation pressure according to
the Tire and Loading Information placard on
the driver’s door B-pillar or, if available, the
supplemental tire pressure information on
the inside of the fuel filler flap.
The TPMS is not able to issue a warning due
to a sudden dramatic loss of pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by care-
fully applying the brakes and avoiding
abrupt steering maneuvers.
323 Operation
Tires and wheels
Rim diameter
The rim diameter4 (
page 322) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (
page 322) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 327) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.For additional information on tire load
rating, see “Load identification”
(
page 325).
Tire speed rating
The tire speed rating6 (
page 322)
indicates the approved maximum speed
for the tire.
Warning!G
The tire load rating must always be at least
half of the GAWR (
page 331) of your
vehicle. Otherwise, tire failure may be the
result which may cause an accident and/or
serious personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!G
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard located on
the driver’s door B-pillar. Overloading the
tires can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
iTire load rating5 (page 322) and Tire
speed rating6 (
page 322) are also referred
to as “service description”.
Warning!G
Even when permitted by law, never operate
a vehicle at speeds greater than the
maximum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire
failure, causing loss of vehicle control and
possibly resulting in an accident and/or
personal injury and possible death, for you
and for others.
331 Operation
Tires and wheels
Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa), or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least three hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GVW (G
ross Vehicle Weight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GWV must never exceed the
GWVR indicated on the certification label
located on the driver’s door B-pillar.
340 Operation
Vehicle care
Cleaning and care of vehicle
Regular and proper care will help to main-
tain the value of your vehicle. The best way
to protect your vehicle from harmful envi-
ronmental influences is to wash it and use
protective treatments regularly.
While in operation, even while parked, your
vehicle is subjected to varying external in-
fluences which, if gone unchecked, can at-
tack the paintwork as well as the
undercarriage and cause lasting damage.Such damage is caused not only by
extreme and varying climatic conditions,
but also by:
Air pollution
Road salt
Tar
Gravel and stone chipping
To avoid paint damage, you should imme-
diately remove:
Grease and oil
Fuel
Coolant
Brake fluid
Bird droppings
Insects
Tree resins, etc.
Frequent washing reduces and/or elimi-
nates the aggressiveness and potency of
the above adverse influences.More frequent washings are necessary to
deal with unfavorable conditions:
near the ocean
in industrial areas (smoke, exhaust
emissions)
during winter operation
You should check your vehicle from time to
time for stone chipping or other damage.
Any damage should be repaired as soon as
possible to prevent corrosion.
In doing so, do not neglect the underbody
of the vehicle. A prerequisite for a
thorough check is a washing of the under-
body followed by a thorough inspection.
Damaged areas need to be
re-undercoated.
Your vehicle has been treated at the
factory with a wax-base rustproofing in the
body cavities which will last for the lifetime
of the vehicle. Post-production treatment
is neither necessary nor recommended by
Mercedes-Benz because of the possibility
Warning!G
Many cleaning products can be hazardous.
Some are poisonous, others are flammable.
Always follow the instructions on the partic-
ular container. Always open your vehicle’s
doors or windows when cleaning the inside.
Never use fluids or solvents that are not de-
signed for cleaning your vehicle.
Always lock away cleaning products and
keep them out of reach of children.
341 Operation
Vehicle care
of incompatibility between materials used
in the production process and others
applied later.
We have selected car-care products and
compiled recommendations which are
specially matched to our vehicles and
which always reflect the latest technology.
You can obtain Mercedes-Benz approved
car-care products at an authorized
Mercedes-Benz Center.
Scratches, corrosive deposits, corrosion or
damage due to negligent or incorrect care
cannot always be removed or repaired with
the car-care products recommended here.
In such cases it is best to seek aid at an
authorized Mercedes-Benz Center.
The following topics deal with the cleaning
and care of your vehicle and give important
“how-to” information as well as references
to Mercedes-Benz approved car-care
products.Power washer
Tar stains
Quickly remove tar stains before they dry
and become more difficult to remove. A tar
remover is recommended.Paintwork, painted body components
Mercedes-Benz approved Paint Care
should be applied when water drops on the
paint surface do not “bead up”. This should
normally be done every 3 to 5 months,
depending on the climate and washing
detergent used.
Mercedes-Benz approved Paint Cleaner
should be applied if the paint surface
shows signs of embedded dirt (i.e. loss of
gloss).
Do not apply any of these products or wax
if your vehicle is parked in the sun or if the
hood is still hot.
Use the appropriate MB-Touch-Up
Stick for quick and provisional repairs
of minor paint damage (i.e. chips from
stones, vehicle doors, etc.).
!Follow the instructions provided by the
power washer manufacturer on maintaining a
distance between the vehicle and the nozzle of
the power washer.
Never use a round nozzle to power-wash tires.
The intense jet of water can result in damage to
the tire.
Always replace a damaged tire.
Always keep the jet of water moving across the
surface. Do not aim directly at electrical parts,
electrical connectors, seals, or other rubber
parts.!Affixing stickers, adhesive tape or similar
materials to painted body components may
damage the paintwork.
395 Practical hints
Unlocking/locking in an emergency
Unlocking and opening the trunk
A minimum height clearance of
5.78 ft (1.76 m) is required to open the
trunk lid.Insert mechanical key 3 into the trunk
lid lock until it stops.
Turn mechanical key 3 counterclock-
wise to position1 until it stops,
and simultaneously
pull trunk lid handle 2 and lift lid.
Turn mechanical key 3 back and
remove it from the trunk lid lock.
Locking the vehicle
If you cannot lock the vehicle with the
SmartKey, do the following:
Close the passenger door and the trunk
lid.
Press the central locking switch in the
upper part of the center console
(
page 103).
Check to see whether the locking knob
on the passenger door has moved
down.
If necessary, push it down manually.
The passenger door is locked.
Exit the vehicle and close the driver’s
door.
1Unlocking
2Handle
3Mechanical key
!Always make sure there is sufficient over-
head clearance.
396 Practical hints
Unlocking/locking in an emergency
Insert mechanical key 2 into the
driver’s door lock until it stops.
Turn mechanical key 2 clockwise to
position1.
The driver’s door is locked.
Turn back mechanical key 2 and
remove it from driver’s door lock.Manually unlocking the gear selector
lever (automatic transmission*)
In case of power failure, the gear selector
lever can be manually unlocked, e.g. to tow
the vehicle.
1Gear selector lever cover
2Release
Insert flat, blunt object (e.g. screw-
driver) into the left edge of cover1 at
the position indicated by the arrows.
Loosen cover1 using this object.
Using your hands, pull cover1 out
and remove.
Push down and hold release2 in
direction of arrow.
Simultaneously move gear selector
lever out of positionP.
The gear selector lever is unlocked
now.1Locking
2Mechanical key
iThis procedure does not arm the anti-theft
alarm system, nor does it lock the fuel filler flap
and the storage compartments.
iThe gear selector lever is locked again as
soon as you place it in positionP again.
408 Practical hints
Flat tire
The SLK 55 AMG with Performance
Package* is equipped with a TIREFIT kit.
Preparing the vehicle
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flashers.
Turn the steering wheel so that the
front wheels are in a straight ahead
position.
Set the parking brake (page 53).
Move the gear selector lever* toP
(manual transmission to first or reverse
gear).
Turn off the engine (page 61).
Remove the SmartKey from the starter
switch.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Sealing tires with TIREFIT
Small tire punctures, particularly those in
the tread, can be sealed with TIREFIT.
TIREFIT can be used in ambient tempera-
tures down to -4°F (-20°C).Foreign objects (e.g. screws or nails)
should not be removed from the tire.
Take TIREFIT, the sticker, and the
electric air pump out of the trunk
(
page 389).
Two-part sticker
1Sticker for instrument cluster
2Sticker for wheel
Attach sticker part 1 where it will be
easily seen by the driver on the instru-
ment cluster.
Attach sticker part 2 to the damaged
tire (close to the tire valve).iOpen door only when conditions are safe to
do so.
iSLK 55 AMG with Performance Package*
only.
Warning!G
TIREFIT is a limited repair device. TIREFIT
cannot be used for cuts or punctures larger
than approximately 0.16 in (4 mm) and tire
damage caused by driving with extremely
low tire inflation pressure, or on a flat tire, or
a damaged wheel.
Do not drive the vehicle under such circum-
stances.
Contact the nearest Mercedes-Benz Center
for assistance or call Roadside Assistance.