2008 MERCEDES-BENZ C300 spare tire

349 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 348) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (
page 348) 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 348) 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 350).Rim diameter
The rim diameter4 (
page 348) 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 348) 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 353) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.

357 Operation
Tires and wheels
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 GVW must never exceed the
GVWR 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 certi-
fication label located on the driver’s door
B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kilopascals (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.Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.

361 Operation
Winter driving
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to
exceed 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 467).

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 467).
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 467).
!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 63) before
setting the vehicle in motion. This will improve
the vehicle’s traction.

384 Practical hints
What to do if …?
Warning!G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
Tire and Loading Information placard on the
driver’s door B-pillar (
page 334) or, if
available, the tire inflation pressure label on
the inside of the fuel filler flap (
page 322).
If your vehicle has tires of a different size
than the size indicated on the Tire and
Loading Information placard or the tire
inflation pressure label, you should deter-
mine the proper tire inflation pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly underinflated tire causes the tire to over-
heat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’s responsibility to maintain correct tire
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
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the mal-
function 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
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.

440 Practical hints
Flat tire
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.
Vehicles with automatic transmission*:
Move the gear selector lever to
positionP (
page 138).
Turn off the engine (page 134).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 135).
Open the driver’s door (this puts
the starter switch in position0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Warning!G
The dimensions of the Minispare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a Minispare wheel
mounted. Adapt your driving style
accordingly.
The Minispare wheel is for temporary use
only. When driving with Minispare wheel
mounted, ensure proper tire inflation
pressure and do not exceed a vehicle speed
of 50 mph (80 km/h).
Contact the nearest Mercedes-Benz Center
as soon as possible to have the Minispare
wheel replaced with a regular road wheel.
Never operate the vehicle with more than
one Minispare wheel mounted.
Do not switch off the ESP
® with a Minispare
wheel mounted.
iOpen the door only when conditions are safe
to do so.

441 Practical hints
Flat tire
Mounting the Minispare wheel
Preparing the vehicle
Prepare the vehicle as described
(
page 440).
Take vehicle tool kit tray and vehicle
jack out of trunk (
page 420).
Take the Minispare wheel from the
wheel well under the trunk floor
(
page 422).Lifting the vehicle
Warning!G
When jacking up the vehicle, only use the
jack which has been specifically approved
by Mercedes-Benz for your vehicle.
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. Make
sure the jack arm is fully seated in the jack
take-up bracket.
The jack is intended only for lifting the
vehicle briefly for wheel changes. It is not
suited for performing maintenance work
under 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 sup-
ported by the jack. Keep hands and feet
away from the area under the lifted vehicle.
Always lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.
Always firmly set the parking brake and
block wheels with wheel chocks or other
sizeable objects before raising vehicle with
jack. Do not release the parking brake while
the vehicle is raised.
Make sure that the ground on which the
vehicle is standing and where you place the
jack is solid, level and not slippery. If neces-
sary, use a large underlay. On slippery
surfaces, such as tiled floors, you should
use a non-slip underlay, for example a
rubber mat.
Do not use wooden blocks or similar objects
to support the jack. Otherwise the jack may
not be able to achieve its load-bearing
capacity if it is not at its full height.
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.
Never start the engine when the vehicle is
raised.
Also observe the notes on the jack.

444 Practical hints
Flat tire
Turn crank3 clockwise until jack 2
is fully seated in take-up bracket1
and the jack base evenly meets the
ground.
Continue to turn crank 3 until the
wheel is a maximum of 1.2 in (3 cm)
from the ground.Removing the wheel
Unscrew and remove the wheel bolts.
Remove the wheel.
Mounting the Minispare wheel
Clean contact surfaces of wheel and
wheel hub.
!Do not place wheel bolts in sand or dirt. This
could result in damage to the bolt and wheel hub
threads.
!To avoid paint damage, place wheel flat
against hub and hold it there while installing first
wheel bolt.
Warning!G
Always replace wheel bolts that are
damaged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be
repaired immediately. Do not continue to
drive under these circumstances! Contact
an authorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect wheel bolts or improperly tight-
ened wheel bolts can cause the wheel to
come off. This could cause an accident.
Make sure you are using the correct wheel
bolts.
Warning!G
Only use 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.


445 Practical hints
Flat tire
Guide the Minispare wheel onto the
wheel hub and push it on.
Insert wheel bolts and tighten them
slightly.
Lowering the vehicle
Lower vehicle by turning crank
counterclockwise until vehicle is
resting fully on its own weight.
Remove the jack.1 - 5 Wheel bolts
6 Wheel wrench
Tighten the five wheel bolts evenly,
following the diagonal sequence
illustrated (1 to 5), until all bolts are
tight. Observe a tightening torque of
96 lb-ft (130 Nm).
Before storing the jack, it should be fully
collapsed, with handle folded in (storage
position).
Store the jack and the other vehicle
tools in the designated storage space
underneath the trunk floor
(
page 420).
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
96 lb-ft (130 Nm).
iVehicles with TPMS (USA only):
Do not activate the tire inflation pressure
monitor (
page 344) until a full size wheel/tire
with functioning sensor has been placed back
into service on the vehicle.