2007 MERCEDES-BENZ SLK CLASS spare wheel

315 Operation
Tires and wheels
Run Flat Indicator*
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.
The Run Flat Indicator may function in a re-
stricted manner or with a delay if:

snow chains are mounted to the
vehicle

winter road conditions prevail

you are driving on a loose surface (e.g.
sand or gravel)

you are driving in a very sporty manner
(involving rapid acceleration or high
speeds in curves)
Warning!G
When the multifunction display shows the
message
Tire pressure Check tires,
one or more of your tires is significantly un-
derinflated. You should stop and check your
tires as soon as possible, and inflate them to
the proper tire inflation pressure as indicat-
ed on the vehicle’s Tire and Loading
Information placard or, if available, on the
tire inflation pressure label. Driving on a sig-
nificantly underinflated tire causes the tire
to overheat and can lead to tire failure. Un-
derinflation also reduces fuel efficiency and
tire tread life, and may affect the vehicle’s
handling and stopping ability. Each tire, in-
cluding the spare, should be checked
monthly when cold and set to the recom-
mended tire inflation pressure as specified
on the Tire and Loading Information placard
on the driver’s door B-pillar (
page 307) or,
if available, on the tire inflation pressure
label located on the inside of the fuel filler
flap (
page 291).
Warning!G
The Run Flat Indicator does not indicate a
warning for wrongly selected tire inflation
pressures. Always adjust tire inflation pres-
sure according to the Tire and Loading
Information placard on the driver’s door
B-pillar (
page 307) or, if available, on the
tire inflation pressure label located on the
inside of the fuel filler flap (
page 291).
The Run Flat Indicator does not replace
regular checks of the tire inflation pressures
since a gradual pressure loss in more than
one tire cannot be detected by the Run Flat
Indicator.
The Run Flat Indicator is not able to issue a
warning due to a sudden dramatic loss of
tire inflation pressure (e.g. tire blowout
caused by a foreign object). In this case
bring the vehicle to a halt by carefully apply-
ing the brakes and avoiding abrupt steering
maneuvers.

319 Operation
Tires and wheels
General:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only. Tire width
The tire width1 (
page 318) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (
page 318) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 318) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal or bias ply construction; letter “B”
means belted-bias ply construction.
At the tire manufacturer’s option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR 18).
For additional information, see “Tire speed
rating” (
page 320).Rim diameter
The rim diameter4 (
page 318) 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 318) 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 324) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.

328 Operation
Tires and wheels
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.GVWR (G
ross Vehicle Weight Rating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on
certification label located on the driver’s
door B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kPa to 1 psi; another metric unit for air
pressure is bars. There are 100 kilopascals
(kPa) to 1 bar.
Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit and production options
weight.

333 Operation
Winter driving
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not higher
than 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.
Please observe the following guidelines
when using snow chains:

Use of snow chains is not permissible
with all wheel/tire combinations
(
page 434).

Use snow chains in pairs and on rear
wheels only. Follow the manufacturer’s
mounting instructions.

Only use snow chains that are
approved by Mercedes-Benz. Any
authorized Mercedes-Benz Center will
be glad to advise you on this subject.

Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.

Do not use snow chains on the spare
wheel (
page 439).
Warning!G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Center.!Some tire sizes do not leave adequate clear-
ance for snow chains. To help avoid serious dam-
age to your vehicle or tires, make sure that the
use of snow chains is permissible as specified in
the “Technical data” section of this Operator’s
Manual, see “Rims and tires” (
page 434).
!If snow chains are mounted to the front
wheels, they may scrape against the body or axle
components. The tires or the vehicle could be
damaged as a result.
iWhen driving with snow chains, you may
wish to deactivate the ESP® (page 88) before
setting the vehicle in motion. This will improve
the vehicle’s traction.

382 Practical hints
Where will I find...?
First aid kit
The first aid kit is stored in a parcel net
behind the driver’s seat.Vehicle tool kit, vehicle jack
The vehicle tool kit is stored in a storage
compartment under the trunk floor.
The following is included:

Collapsible wheel chock

Vehicle jack

Protective wrap (except SLK 55 AMG
with Performance Package)

Alignment bolt

Towing eye bolt

Wheel wrench

Spare fuses

Fuse extractor

Valve extractor

Electric air pump

TIREFIT kit (SLK 55 AMG with
Performance Package only)Removing the vehicle tool kit
Vehicles with spare wheel
Open the trunk (page 100).
Lift up trunk floor.
Remove the spare wheel (page 385).
You can now access the vehicle tool
kit.
iCheck expiration dates and contents for
completeness at least once a year and replace
missing/expired items.

383 Practical hints
Where will I find...?
1Collapsible wheel chock
2Vehicle jack
3Protective wrap
4Alignment bolt
5Towing eye bolt
6Wheel wrench
7Spare fuses, fuse extractor and valve
extractor
8Electric air pumpVehicles with TIREFIT*
1TIREFIT kit
2Vehicle jack
3Collapsible wheel chock
4Towing eye bolt
5Alignment bolt
6Wheel wrench
7Spare fuses, fuse extractor and valve
extractor
8Electric air pump
Open the trunk (page 100).
Lift up trunk floor.Vehicle jack
Warning!G
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. To help
avoid personal injury, use the jack only to lift
the vehicle during a wheel change. Never
get beneath the vehicle while it is supported
by the jack. Keep hands and feet away from
the area under the lifted vehicle. Always
firmly set parking brake and block wheels
before raising vehicle with jack.
Do not disengage parking brake while the
vehicle is raised. Be certain that the jack is
always vertical (plumb line) when in use,
especially on hills. Always try to use the jack
on level surface. Make sure the jack arm is
fully seated in the jack take-up bracket. Al-
ways lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.

385 Practical hints
Where will I find...?
Tilt both plates upward1.
Fold the lower plate outward2.
Guide the tabs of the lower plate all the
way into the openings of the base
plate3.
For information on where to place wheel
chocks when changing a wheel, see
“Lifting the vehicle” (
page 407).
Spare wheel with collapsible tire
The spare wheel is located in the storage
compartment underneath the trunk floor.
1Spare wheel, spare wheel bolts
(located under plastic cover on the
outside of spare wheel rim)
2Vehicle tool kit (under spare wheel)
3Retaining screwOpen the trunk (page 100).
Lift up trunk floor.
Loosen retaining screw3by turning it
counterclockwise.
Remove spare wheel1.
Take off the wheel bolts for spare
wheel1.
Storing the spare wheel with
collapsible tire
If you wish to store the spare wheel after
use, carry out the following steps. Other-
wise the spare wheel will not fit the storage
compartment.
Unscrew the valve cap from the valve
of the collapsible tire.
Take the valve extractor from the vehi-
cle tool kit (
page 382).
!Make sure the collapsible tire is dry when
storing it.


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.