2005 MERCEDES-BENZ C COUPE flat tire

323 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 one mile (1.6 km). Curb weight
The weight of a motor vehicle with
standard equipment including the maxi-
mum capacity of fuel, oil, and coolant, and,
if so equipped, air conditioning and
additional optional equipment, but without
passengers and cargo.
DOT (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
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.

324 OperationTires and wheelsGVW (G
ross V
ehicle W
eight)
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 V
ehicle W
eight R
ating)
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 one psi; another metric unit for
air pressure is bars. There are
100 kilopascals (kPa) to one 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,
vehicle capacity weight 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.

325 Operation
Tires and wheels
PSI (P
ounds per s
quare i
nch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure
listed on placard located on driver's door
B-pillar for normal driving conditions.
Provides best handling, tread life and
riding comfort.
Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.TIN (T
ire I
dentification N
umber)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Traction
Force exerted by the vehicle on the road
via the tires. The amount of grip provided.
Tread
The portion of a tire that comes into
contact with the road.
Treadwear indicators
Narrow bands, sometimes called
“wear bars” that show across the tread of
a tire when only
1/6in (1.6 mm) of tread
remains.

326 OperationTires and wheelsUniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire's traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The
ratings are molded into the sidewall of the
tire.
Vehicle capacity weight
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle's
designated seating capacity.
Vehicle maximum load on the tire
Load on an individual tire that is
determined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing it by two.
Rotating tires
Tire rotation can be performed on vehicles
with tires of the same dimension all
around. If your vehicle is equipped with
tires of the same dimension all around,
tires can be rotated, observing a a
front-to-rear rotation pattern that will
maintain the intended rotation (spinning)
direction of the tire (
page 303).
In some cases, such as when your vehicle
is equipped with mixed-size tires (different
tire dimension front vs. rear), tire rotation
is not possible.If applicable to your vehicle's tire configu-
ration, tires can be rotated according to
the tire manufacturer's recommended in-
tervals in the tire manufacturer's warranty
pamphlet located in your vehicle literature
portfolio. If none is available, tires should
be rotated every 3 000 to 6 000 miles
(5 000 to 10 000 km), or sooner if neces-
sary, according to the degree of tire wear.
The same rotation (spinning) direction
must be maintained (
page 303).
Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.
Warning!
G
Rotate front and rear wheels only if the tires
are of the same dimension.
If your vehicle is equipped with mixed-size
tires (different tire dimensions front vs.
rear), tire rotation is not possible.

339 Practical hints
What to do if …
Where will I find ...?
Unlocking/locking in an emergency
Opening/closing in an emergency
Replacing SmartKey batteries
Replacing bulbs
Replacing wiper blades
Flat tire
Battery
Jump starting
Towing the vehicle
Fuses

376 Practical hintsWhere will I find ...?Storing the spare wheel
If you wish to store the spare wheel after
use, carry out the following steps. Other-
wise the spare wheel will not fit the wheel
well.
Unscrew the valve cap from the valve
of the spare wheel.

Carefully push the tip of the valve cap
into the spare wheel valve and allow
the air to escape.

Screw the valve cap back on the valve.

Place spare wheel1 in wheel well.

Turn retaining screw3 clockwise to
its stop to secure the spare wheel.

Install the trunk floor.Spare wheel bolts
1Wheel bolt for light alloy rims
2Wheel bolt for light alloy spare wheel
rim size 4
1/2B x15 H2For more information on model and spare
wheel rim size, see “Technical data”
section (
page 422).
iIt may take a few minutes for the col-
lapsible tire to deflate completely.
!Wheel bolts2 must be used when
mounting spare wheel rim
size 4
1/2Bx15 H2 (
page 422).
The use of any wheel bolts other than
wheel bolts2 for spare wheel rim
size 4
1/2B x15 H2 can cause physical
damage to the vehicle.
Warning!
G
Make sure to use the original length wheel
bolts when remounting the original wheel af-
ter it has been repaired.

394 Practical hintsFlat tire
Preparing the vehicle
Park the vehicle as far as possible from
moving traffic on a hard surface.

Turn on the hazard warning flashers.

Turn the steering wheel so that the
front wheels are in a straight ahead
position.

Move the gear selector lever toP
(manual transmission to first or reverse
gear).

Turn off the engine (
page 58).

Remove the SmartKey from the starter
switch.

Have any passenger exit the vehicle at
a safe distance from the roadway.
Mounting the spare wheel
Preparing the vehicle
Prepare the vehicle as described
(page 394).

Take the wheel wrench and the jack
out of wheel well below the trunk floor
(page 373).

Take the spare wheel out of the trunk
(page 375).
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
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted, en-
sure proper tire 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.

395 Practical hints
Flat tire
Lifting the vehicle
Prevent the vehicle from rolling away
by blocking wheels with wheel chocks
or other sizable objects.
One wheel chock is included with
vehicle tool kit (
page 373).
When changing wheel on a level surface:

Place the wheel chock (located in the
vehicle tool kit) in front of and another
sizable object behind the wheel that is
diagonally opposite to the wheel being
changed.
When changing wheel on a hill:

Place the wheel chock and other size-
able object on the downhill side block-
ing both wheels of the other axle.

Take the two-piece wheel wrench and
the jack out of the vehicle tool kit
(page 373). Assemble wheel wrench.

On wheel to be changed, loosen but do
not yet remove the wheel bolts
(approximately one full turn with
wrench).
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, es-
pecially 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.
Always lower the vehicle onto sufficient
capacity jackstands before working under
the vehicle.