386 Practical hints
Where will I find...?
Unscrew the valve insert from the valve
and allow the air to escape.
Screw the valve insert back into the
valve.
Screw the valve cap back on the valve.
Pull the protective wrap provided with
the vehicle tool kit over the spare
wheel.
Store the spare wheel and the valve
extractor in the storage compartment
underneath the trunk floor.
Pierce the protective wrap with retain-
ing screw3.
Secure the spare wheel by turning
retaining screw3 clockwise.
For information on mounting the spare
wheel, see “Flat tire” (
page 401).
Spare wheel bolts
1Wheel bolt for light alloy rims
2Wheel bolt for spare wheel with
collapsible tire (located under plastic
cover on the outside of spare wheel
rim)
iIt may take a few minutes for the collapsible
tire to deflate completely.
!Wheel bolts2 must be used when mount-
ing the spare wheel with collapsible tire. The use
of any wheel bolts other than wheel bolts2 for
the spare wheel with collapsible tire will physi-
cally damage the vehicle’s brakes.
401 Practical hints
Flat tire
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 382).
iOpen door only when conditions are safe to
do so.
iSLK 55 AMG with Performance Package*
only.
Warning!G
Keep TIREFIT away from sparks, open flame
or heat source.
Do not smoke.
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.
405 Practical hints
Flat tire
After attaining a tire inflation pressure
of 26 psi (1.8 bar), press0 on electric
air pump switch8 (
page 403).
The electric air pump is switched off.
Turn the SmartKey in the starter switch
to position0 (
page 37).
Detach the electric air pump.
The air hose may still be hot. Please
exercise appropriate caution.
Place the electrical air pump back in
the trunk.
Close the trunk lid.
Drive off immediately.
The TIREFIT sealant will distribute itself
evenly inside the tire.
After driving the vehicle for an initial
10 minutes, check the tire inflation
pressure using pressure gauge 9 on
the air pump.
Warning!G
If a tire inflation pressure of 26 psi (1.8 bar)
is not attained, the tire is too severely
damaged for TIREFIT to provide a reliable
tire repair.
In this case, TIREFIT cannot properly seal
the tire.
Do not drive the vehicle.
Contact the nearest Mercedes-Benz Center
or call Roadside Assistance.
Warning!G
Do not exceed vehicle speed of
50 mph (80 km/h). A TIREFIT repair is not
designed to operate at higher speeds.
The sticker must be attached on the instru-
ment cluster where it will be easily seen by
the driver.
Vehicle handling characteristics may
change. Adapt your driving accordingly.
Warning!G
If tire inflation pressure has fallen below
20 psi (1.3 bar) do not continue to drive the
vehicle.
Park your vehicle safely away from the road-
way and contact the nearest authorized
Mercedes-Benz Center or Roadside
Assistance.
Have the damaged tire replaced.
407 Practical hints
Flat tire
Mounting the spare wheel
Preparing the vehicle
Prepare the vehicle as described
(
page 401).
Take the spare wheel, wheel wrench,
wheel bolts, jack, and electric air pump
out of the trunk (
page 382).Lifting the vehicle
Prevent the vehicle from rolling away
by blocking wheels with wheel chocks
(not included) or other sizeable ob-
jects.
One wheel chock is included with the
vehicle tool kit (
page 383).
When changing wheel on a level surface:
Place one wheel chock or other size-
able object in front of and another
wheel chock or other sizeable object
behind the wheel that is diagonally
opposite to the wheel being changed.
Always try lifting the vehicle using the jack
on a level surface. However, should cir-
cumstances require you to do so on a hill,
place the wheel chock or other sizeable
object and the other wheel chock or other
sizeable object as follows:
Place wheel chocks and other sizeable
objects on the downhill side blocking
both wheels of the axle not being
worked on.
Warning!G
The dimensions of the spare wheel are dif-
ferent from those of the road wheels. As a
result, the vehicle handling characteristics
change when driving with a spare wheel with
collapsible tire mounted. Adapt your driving
style accordingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted,
ensure proper tire inflation pressure and do
not exceed vehicle speed of 50 mph
(80 km/h).
Drive to the nearest Mercedes-Benz Center
as soon as possible to have the spare wheel
replaced with a regular road wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® when a spare
wheel is mounted.
411 Practical hints
Flat tire
Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.
Inflate the collapsible tire
(
page 411).Inflating the collapsible tire
1Flap
2Air pump switch
3Electrical plug
4Air hose with pressure gauge and vent
screw
5Union nut
Take the electric air pump out of the
trunk (
page 383).
Open flap1 on air pump.
Pull out electrical plug3 and air hose
with pressure gauge4.
Close vent screw on air hose4.
Remove the valve cap from the tire
valve.
Screw union nut5 onto the tire valve.
Make sure electric air pump switch2
is set to0.
Insert electrical plug3 into the power
outlet in the passenger footwell
(
page 257).
Turn the SmartKey in the starter switch
to position1.
Warning!G
Use only genuine Mercedes-Benz wheel
bolts. Other wheel bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise the vehicle
could fall off the jack.Warning!G
Observe instructions on air pump label.
!Do not lower the vehicle before inflating the
collapsible tire. Otherwise the rim may be
damaged.
!The cigarette lighter (page 256) is not de-
signed for use with the electric air pump. Use the
power outlet in the passenger footwell
(
page 257) for electric air pump operation.
412 Practical hints
Flat tire
PressI on electric air pump switch2.
The electric air pump switches on and
inflates the collapsible tire.
Inflate the collapsible tire to approxi-
mately 51 psi (3.5 bar).
This takes about 5 minutes. Air
hose4 and union nut5 can become
hot during inflation. Exercise proper
caution to avoid burning yourself when
using the equipment.
Press0 on electric air pump switch2.
Turn the SmartKey in the starter switch
to position0.
The electric air pump is switched off.
If the tire inflation pressure is above
51 psi (3.5 bar), release excess tire
inflation pressure using the vent screw
on air hose4.
Detach the electric air pump.
Reinstall tire valve cap.
Store electrical plug3 and air
hose4 behind flap 1 and place the
electric air pump back in the trunk.
Lower the vehicle (page 413).
!Compare the recommended tire inflation
pressure for your vehicle with the tire inflation
pressure on the yellow label located on the spare
wheel rim.
If the tire inflation pressure on the yellow label
on the spare wheel rim differs from the values
given in this Operator’s Manual, inflate the
collapsible tire to the recommended tire inflation
pressure given on the yellow label on the spare
wheel rim.
!Do not operate the electric air pump longer
than 6 minutes without interruption. Otherwise it
may overheat.
You may operate the electric air pump again
after it has cooled off.Warning!G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
413 Practical hints
Flat tire
Lowering the vehicle
Lower vehicle by turning the crank
counterclockwise until vehicle is
resting fully on its own weight.
Remove the jack.
1-5 Wheel bolts
Tighten the five wheel bolts evenly in
the direction of the arrow, following the
diagonal sequence illustrated
(1to5), until all bolts are tight.
Observe a tightening torque of
80 lb-ft (110 Nm).
Fully collapse the jack.
Place the vehicle tool kit, electric air
pump, and the jack back in the storage
compartment underneath the trunk
floor.
Wrap the damaged wheel in the protec-
tive sheet provided with the vehicle
tool kit and put the wheel in the trunk.
For information on storing the spare wheel
in the trunk after it has been replaced by a
regular road wheel, see “Storing the spare
wheel with collapsible tire” (
page 385).
Warning!G
Inflate the collapsible tire using the electric
pump (
page 411) before lowering the
vehicle.
Warning!G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
80 lb-ft (110 Nm).
iThe flat tire may be transported in the trunk
when the retractable hardtop is closed.
414 Practical hints
Flat tire
MOExtended system*
The MOExtended system allows you to
continue driving your vehicle even if there
is a total loss of pressure in one or more
tires.
You may only use the MOExtended system
in conjunction with the Run Flat Indicator*
(
page 315).
!The maximum distance in emergency mode
depends on the vehicle’s load. It is 30 miles
(50 km) if the vehicle is partially loaded and
18 miles (30 km) if the vehicle is fully loaded.
The point at which the maximum driving distance
begins in emergency mode is when the warning
message appears in the multifunction display
indicating that there is a loss of tire inflation
pressure.
Do not exceed the maximum speed of
50 mph (80 km/h).
Warning!G
In emergency mode, your vehicle’s driving
characteristics are diminished in such situa-
tions as:
driving around curves
while braking
while accelerating rapidly
Therefore, your driving style must be adapt-
ed accordingly. Avoid abrupt steering and
driving maneuvers, as well as driving over
obstacles (road curbs, potholes, or off-road
areas). This is especially important if the
vehicle is heavily loaded.
The emergency driving distance that can be
achieved greatly depends on the demands
placed on the vehicle. Depending on speed,
load, driving maneuvers, road conditions,
outside temperature, etc., the distance can
be significantly shorter or, if the vehicle is
driven cautiously, somewhat longer.
Do not continue driving in emergency mode
if
you notice knocking sounds
the vehicle starts to shake
smoke develops and you smell rubber
ESP® is intervening continuously
you notice tears on the tire sidewalls
After driving in emergency mode, you must
have the rims inspected by an authorized
Mercedes-Benz Center to check if they are
suitable for further use. The failed tire must
be replaced in any case.
iWhen replacing individual or all tires on the
vehicle, make sure only tires marked
with“MOExtended” are mounted in the size
specified for your vehicle (
page 434).