2008 MERCEDES-BENZ C300 4MATIC Owner's Manual

312 Operation
Driving instructions
Brakes
To help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.
Refer to the description of the Brake Assist
System (BAS) (
page 60).
Brake pad wear or a leak in the system may
be the reason for low brake fluid level in
the reservoir.
The brake fluid level in the reservoir may
be too low if the red brake warning lamp in
the instrument cluster comes on while the
engine is running and an acoustic warning
sounds (
page 376). Observe additional
messages in the multifunction display that
may appear (
page 387).
Warning!G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking
effect. Maintain a safe distance from
vehicles in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an
accident.
!Vehicles without 4MATIC:
Because the ESP® operates automatically, the
engine and ignition must be shut off (SmartKey
in starter switch position0 or1 or KEYLESS-GO
(Canada only) start/stop button* in position0
or1) when

the parking brake is being tested on a brake
test dynamometer

the vehicle is being towed with the front axle
raised
Active braking action through the ESP
® may oth-
erwise seriously damage the brake system.
For information on vehicles with 4MATIC, see
“Four wheel electronic traction system (4MATIC)
with the ESP®” (
page 65).
Warning!G
Make sure not to endanger any other road
users when carrying out these braking ma-
neuvers.

313 Operation
Driving instructions
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream can cool down
the brakes faster.
Warning!G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
!When driving down long and steep grades,
relieve the load on the brakes by shifting into a
lower gear to use the engine’s braking power.
This helps prevent overheating of the brakes and
reduces brake pad wear.
When using the engine’s braking power, a drive
wheel may not spin for an extended period of
time, e.g. on slippery road surfaces.This may cause serious damage to the drivetrain
which is not covered by the Mercedes-Benz Lim-
ited Warranty.

314 Operation
Driving instructions
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.Parking
!When driving off on a slippery surface, do
not allow a drive wheel to spin for an extended
period with the ESP
® switched off. Doing so may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited War-
ranty.
!Simultaneously depressing the accelerator
pedal and applying the brakes reduces engine
performance and causes premature brake and
drivetrain wear.
Warning!G
Do not park this vehicle in areas where
combustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
To reduce the risk of personal injury, or
damage to the vehicle or the vehicle
drivetrain, as a result of vehicle movement,
always do the following before turning off
the engine and leaving the vehicle:

Keep right foot on brake pedal.

Manual transmission: Move the gear
shift lever to neutral position (no gear
selected).

Firmly depress the parking brake.

Manual transmission: Move the gear
shift lever into first or reverse gear.

Automatic transmission*: Move the
gear selector lever to positionP.

Slowly release brake pedal.

When parked on an incline, turn front
wheels towards the road curb.

Turn the SmartKey or the SmartKey
with KEYLESS-GO* (Canada only) to
starter switch position0 and remove, or
press the KEYLESS-GO* start/stop but-
ton.

Take the SmartKey or the SmartKey with
KEYLESS-GO
* with you and lock the
vehicle when leaving.

315 Operation
Driving instructions
Tires
Treadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and be-
come visible at a tread depth of approxi-
mately
1/16in (1.6 mm), at which point the
tire is considered worn and should be
replaced.The treadwear indicator appears as a solid
band across the tread.
Specified tire inflation pressures must be
maintained. This applies particularly if the
tires are subject to extreme operating con-
ditions (e.g. high speeds, heavy loads, high
ambient temperatures).For more information, see “Tires and
wheels” (
page 331).
Hydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur, even
at low speeds and with new tires. Reduce
vehicle speed, avoid track grooves in the
road and apply brakes cautiously in the
rain.
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to
the nearest Mercedes-Benz Center or tire
dealer for repairs.
Warning!G
Although the applicable federal motor vehi-
cle safety laws consider a tire to be worn
when the treadwear indicators (TWI) be-
come visible at approximately
1/16 in
(1.6 mm), we recommend that you do not al-
low your tires to wear down to that level. As
tread depth approaches
1/8 in (3 mm), the
adhesion properties on a wet road are
sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.

316 Operation
Driving instructions
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.Mercedes-Benz recommends winter tires
(
page 360) with a minimum tread depth
of approximately 1/6in (4 mm) on all four
wheels for the winter season to ensure
normal balanced handling characteristics.
On packed snow, they can reduce your
stopping distance compared to summer
tires.
Stopping distance, however, is still consid-
erably greater than when the road is not
covered with snow or ice. Exercise appro-
priate caution.
Tire speed rating
Regardless of the tire speed rating, local
speed limits should be obeyed. Use pru-
dent driving speeds appropriate to prevail-
ing conditions.
Warning!G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
!Avoid spinning of a drive wheel. This may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.
Warning!G
Even when permitted by law, never operate
a vehicle at speeds greater than the maxi-
mum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire fail-
ure, causing loss of vehicle control and pos-
sibly resulting in an accident and/or serious
personal injury and possible death, for you
and for others.

317 Operation
Driving instructions
An electronic speed limiter prevents your
vehicle from exceeding a speed of 130
mph (210 km/h).
The factory equipped tires on your vehicle
may have a tire speed rating above the
maximum speed permitted by the elec-
tronic speed limiter.
Make sure your tires have the required tire
speed rating as specified for your vehicle in
the “Technical data” section (
page 467),
for example when purchasing new tires.
For information on how to identify the tire
speed rating on a tire’s sidewall, see “Tire
size designation, load and speed rating”
(
page 348).
If you are uncertain about the correct read-
ing of the information given on a tire’s side-
wall, any authorized Mercedes-Benz
Center will be glad to assist you.
Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
move gear selector lever to position N. Try
to keep the vehicle under control by cor-
rective steering action.Road salts and chemicals can adversely
affect braking efficiency. Increased pedal
force may become necessary to produce
the normal braking effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt impaired braking
efficiency back to normal.
If the vehicle is parked after being driven
on salt-treated roads, the braking efficien-
cy should be tested as soon as possible af-
ter driving is resumed.
iFor information on speed ratings for winter
tires, see (
page 351) and (page 360).
iFor information on driving with snow chains,
see “Snow chains” (
page 361).
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking ma-
neuvers.

318 Operation
Driving instructions
For more information on winter driving, see
“Winter driving” (
page 360).
Standing waterPassenger compartment
Driving abroad
Abroad, there is an extensive
Mercedes-Benz service network at your
disposal. If you plan to drive into areas
which are not listed in the index of your
Mercedes-Benz Center directory, you
should request pertinent information from
an authorized Mercedes-Benz Center.
Warning!G
If the vehicle becomes stuck in snow, make
sure that snow is kept clear of the exhaust
pipe and from around the vehicle while the
engine is running. Otherwise, deadly carbon
monoxide (CO) gases may enter vehicle in-
terior resulting in unconsciousness and
death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the ve-
hicle not facing the wind.
Warning!G
The outside temperature indicator is not de-
signed to serve as an ice-warning device and
is therefore unsuitable for that purpose. In-
dicated temperatures just above the freez-
ing point do not guarantee that the road
surface is free of ice.
!Do not drive through flooded areas or water
of unknown depth. Before driving through water,
determine its depth. Never accelerate before
driving into water. The bow wave could force wa-
ter into the engine and auxiliary equipment, thus
damaging them.
If you must drive through standing water, drive
slowly to prevent water from entering the pas-
senger compartment or the engine compart-
ment. Water in these areas could cause damage
to electrical components or wiring of the engine
or transmission, or could result in water being in-
gested by the engine through the air intake caus-
ing severe internal engine damage. Any such
damage is not covered by the Mercedes-Benz
Limited Warranty.
Warning!G
Always fasten items being carried as secure-
ly as possible.
In an accident, during hard braking or sud-
den maneuvers, loose items will be thrown
around inside the vehicle, and cause injury
to vehicle occupants unless the items are
securely fastened in the vehicle.
The trunk is the preferred place to carry
objects.

319 Operation
Driving instructions
Control and operation of radio
transmitters
COMAND*, radio, and telephone*Telephones and two-way radios
Radio transmitters, such as a portable tele-
phone or a citizens band unit should only
be used inside the vehicle if they are con-
nected to an antenna that is installed on
the outside of the vehicle.
Refer to the radio transmitter operation in-
structions regarding use of an external an-
tenna.
Catalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Maintenance Booklet.
Warning!G
Please do not forget that your primary re-
sponsibility is to drive the vehicle safely.
Only operate the COMAND (Cockpit Man-
agement and Data System), radio, or tele-
phone
1 if road, weather and traffic
conditions permit. Otherwise, you may not
be able to observe traffic conditions and
could endanger yourself and others.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h), your vehicle is
covering a distance of 44 feet (approximate-
ly 14 m) every second.
1Observe all legal requirements.
Warning!G
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system, pos-
sibly resulting in an accident and/or
personal injury.
!To prevent damage to the catalytic convert-
ers, only use premium unleaded gasoline in this
vehicle.
Any noticeable irregularities in engine operation
should be repaired promptly. Otherwise, exces-
sive unburned fuel may reach the catalytic con-
verter, causing it to overheat and potentially
start a fire.