2003 MERCEDES-BENZ C320 COUPE Owner's Manual

233 Operation
Tires and wheels
Tires and wheels
See your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation. They can also offer ad-
vice concerning tire service and purchase
Retread tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
See your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation.
Important guidelines

Use only sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage.


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension compo-
nents can be damaged


The correct operating clearance of the
wheels and the tires are no longer guar-
anteed
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, use only genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.

234 OperationTires and wheelsLife of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style


Tire pressure


Distance driven
Direction of rotation
Unidirectional tires offer added advantag-
es, such as better aquaplaning perfor-
mance. To benefit, however, you must
ensure that the tires rotate in the direction
specified.
An arrow on the sidewall indicates the in-
tended direction of tire rotation.Checking tire inflation pressure
Correct the tire pressure only when tires
are cold.
Regularly check your tire pressure at inter-
vals of no more than 14 days. If the tires are warm you should only cor-
rect the tire pressure if it is too low for cur-
rent operating conditions.
A table on the fuel filler flap lists the spec-
ified tire inflation pressures for warm and
cold tires as well as for various operating
conditions.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.
Warning!
G
If the tire pressure repeatedly drops

check the tires for punctures from for-
eign objects


check to see whether air is leaking from
the valves or from around the rim
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed in the fuel filler flap.

235 Operation
Tires and wheels
Tire pressure changes by approximately
1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind
when checking tire pressure where the
temperature is different from the outside
temperature.
Tire temperature and tire pressure are also
increased while driving, depending on the
driving speed and the tire load.Check the spare tire periodically for condi-
tion and inflation. Spare tires will age and
become worn over time even if never used,
and thus should be inspected and replaced
when necessary.
Rotating wheels
On vehicles with the same wheel size all
around, wheels can be rotated every 3000
to 6000 miles (5 000 to 10 000 km), or sooner if necessary, according to the de-
gree of tire wear. The same direction of tire
rotation must be retained.
Rotate the wheels before the characteris-
tic tire wear pattern becomes visible
(shoulder wear on front wheels and tread
center wear on rear wheels).
Thoroughly clean the inner side of the
wheels after each rotation. Check and en-
sure proper tire inflation pressure.
Warning!
G
Follow recommended inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.Warning!
G
Rotate front and rear wheels only if they are
of the same size.
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
80 ft.lb. (110 Nm).
Use only genuine Mercedes-Benz wheel
bolts specified for your vehicle's rims.

236 OperationWinter driving
Winter drivingBefore the onset of winter have your vehi-
cle winterized at an authorized
Mercedes-Benz Center. This service in-
cludes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent / antifreeze which is formulated
for below freezing temperatures
(page 324).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
that the engine can be started, even at
low ambient temperatures.


Tire change. We recommend M+S rat-
ed radial-ply tires on all four wheels for
the winter season.
Winter tires
Always use winter tires at temperatures
below 39°F (4°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS and ESP in winter
operation.
For safe handling, ensure that all mounted
winter tires are of the same make and have
the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-
tices are available from your tire dealer or
from any authorized Mercedes-Benz Cen-
ter.
Warning!
G
Winter tires with a tread depth under 0.16 in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.

237 Operation
Winter driving
Block heater (Canada only)
The engine is equipped with a block heat-
er.
The electrical cable may be installed at
your authorized Mercedes-Benz Center.
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to ex-
ceed 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.


Chains should only be used on the rear
wheels. Follow the manufacturer's
mounting instructions.


Use only snow chains that are ap-
proved by Mercedes-Benz. Your autho-
rized Mercedes-Benz Center will be
glad to advise you on this subject.
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.
iWhen driving with snow chains, you
may wish to deactivate the ESP
(page 75) before setting the vehicle
in motion. This will improve the vehi-
cle‘s traction.
!Use of snow chains is not permissible
with tire sizes 225/ 50 R16 and with
tire sizes 225/45 R17.

238 OperationMaintenance
MaintenanceWe strongly recommend that you have
your vehicle serviced by your authorized
Mercedes-Benz Center, in accordance with
the Service Booklet at the times called for
by the FSS (F
lexible S
ervice S
ystem).
Failure to have the vehicle maintained in
accordance with the Service Booklet at the
designated times /mileage called for by
the FSS may result in vehicle damage not
covered by the Mercedes-Benz Limited
Warranty.
FSS will notify you when your next service
is due.
Approximately one month before your next
service is due, one of the following mes-
sages will appear in the multifunction dis-
play while you are driving or when you
switch on the ignition (example service A):
SERVICE A - IN xx DAYS
SERVICE A - IN xx MILES (KM)
SERVICE A - DUE NOW
The type of service due is indicated in the
multifunction display field:9
Minor service (A)
´
Major service (B)
Clearing the service indicator
The service indicator is automatically
cleared

after 10 seconds when you switch on
the ignition or when reaching the ser-
vice threshold while driving.


after 30 seconds, once the suggested
service term had passed.
You can also clear it yourself by pressing
the reset knob on the instrument cluster
(
page 22).
Service term exceeded
If you have exceeded the suggested ser-
vice term a signal sounds every time when
you switch on the ignition and you will see
the following message in the multifunction
display:SERVICE A EXCEEDED BY xx DAYS
SERVICE A EXCEEDED BY xx MILES (KM)
iThe interval between services depends
on your driving habits. A gentle driving
style, moderate engine speeds and the
avoidance of short distance trips will
lengthen the interval between services.

239 Operation
Maintenance
The Mercedes-Benz Center will reset the
service indicator following a completed
service.Calling up the service indicator
Switch ignition on.
The standard display of the control sys-
tem appears (
page 105).

Press button
k
or
j
on the mul-
tifunction steering wheel until the FSS
indicator appears in the multifunction
display.
Resetting the service indicator
In the event that the service on your vehi-
cle is not carried out by an authorized
Mercedes-Benz Center, you can reset the
service indicator yourself.
Switch ignition on.
The standard display of the control sys-
tem appears (
page 105).

Press button
k
or
j
on the mul-
tifunction steering wheel until the FSS
indicator appears in the display.

Press the reset knob for about four
seconds.
This message appears in the display:DO YOU WANT TO RESET SERVICE INTER-
VAL? CONFIRM BY PRESSING RESET (R)
BUTTON

To confirm, hold down the reset knob
for about four seconds.
The service indicator now displays the
reset interval.
iIf the battery is disconnected, the days
of disconnection will not be included in
the count shown by the service indica-
tor. To arrive at the true service dead-
line, you will need to subtract these
days from the days shown in the ser-
vice indicator.
Do not confuse the service indicator
with the engine oil level indicator
:
.
iIf the service indicator was inadvertent-
ly reset, have a Mercedes-Benz Center
correct it.
Only reset if the proper service has
been performed. Resetting the system
without performing the proper service
as called for by the FSS will cause the
FSS to incorrectly determine the next
service interval which will result in en-
gine damage not covered by the
Mercedes-Benz Limited Warranty.

240 OperationVehicle care
Vehicle careCleaning and care of vehicle
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
underbody and cause lasting damage.
Such damage is caused not only by ex-
treme and varying climatic conditions, but
also by:

Air pollution


Road salt


Tar, gravel and stone chippingTo avoid paint damage, you should imme-
diately remove:


Grease and oil


Fuel


Coolant


Brake fluid


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 operationYou 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 thor-
ough check is a washing of the underbody
followed by a thorough inspection. Dam-
aged areas need to be re-undercoated.
Your vehicle has been treated at the facto-
ry 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
of incompatibility between materials used
in the production process and others ap-
plied 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 your authorized
Mercedes-Benz Center.
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.