Page 338 of 506

337 Operation
Tires and wheels
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.
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.
Page 341 of 506

340 OperationWinter drivingBefore the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:
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 temperatures below freezing point
(page 460).
Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure that the engine can be started
even at low ambient temperatures.
Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately 1/6 in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum
effectiveness of the ABS and the ESP in
winter operation.
For safe handling, make sure 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 at your tire dealer or any
authorized Mercedes-Benz Center.Warning!
G
Winter tires with a tread depth under
1/6in
(4 mm) must be replaced. They are no
longer suitable for winter operation.
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.
Page 346 of 506

345 Operation
Vehicle care
Vehicle care
Cleaning and care of vehicle
While in operation, even while parked, your
vehicle is subject to varying external
influences which, if gone unchecked, can
attack the paintwork as well as the
underbody and cause lasting damage.Such damage is caused not only by
extreme and varying climatic conditions,
but also by:
Air pollution
Road salt
Tar
Gravel and stone chipping
To avoid paint damage, you should
immediately remove:
Grease and oil
Fuel
Coolant
Brake fluid
Bird droppings
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 operation
You 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
applied later.
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
designed for cleaning your vehicle.
Page 364 of 506

363 Practical hints
What to do if …?
Vehicle status messages in the multifunction display
Warning and malfunction messages
appear in the multifunction display located
in the instrument cluster.
Certain warning and malfunction messag-
es are accompanied by an audible signal.
Address these messages accordingly and
follow the additional instructions given in
this Operator’s Manual.
Selecting the vehicle status message
memory menu in the control system
(page 141) displays both cleared and
uncleared messages.
High-priority messages appear in the
multifunction display in red color.Certain messages of high priority cannot
be cleared from the multifunction display
using the reset button (
page 130) or
button k,j, è, orÿ on the
steering wheel.
Other messages of high priority and
messages of less immediate priority can
be cleared from the multifunction display
using the reset button (page 130) or
button k,j, è, orÿ on the
steering wheel. They are then stored in the
vehicle status message memory
(
page 141). Remember that clearing a
message will only make the message dis-
appear. Clearing a message will not
correct the condition that caused the
message to appear.
Warning!
G
All categories of messages contain
important information which should be
taken note of and, where a malfunction is
indicated, addressed as soon as possible at
an authorized Mercedes-Benz Center.
Failure to repair condition noted may cause
damage not covered by the Mercedes-Benz
Limited Warranty, or result in property
damage or personal injury.Warning!
G
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
Contact your nearest authorized
Mercedes-Benz Center.
Page 444 of 506
443 Technical data
Layout of poly-V-belt drive
Layout of poly-V-belt drive
CLK 320/CLK 500/CLK 55 AMG
1Automatic belt tensioner
2Power steering pump
3Air conditioning compressor
4Crankshaft
5Coolant pump
6Generator (alternator)
7Idler pulley
Page 455 of 506
454 Technical dataFuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants, etc.
Cooling system
CLK 320
CLK 500
CLK 55 AMG
approx. 10.7 US qt (10.0 l)
approx. 12.8 US qt (12.0 l)
approx. 12.8 US qt (12.0 l)
MB 325.0 Anticorrosion/Antifreeze
Agent
Fuel tank
including a reserve of
CLK 320
CLK 500
CLK 55 AMG
16.35 US gal (62.0 l)
2.11 US gal (8.0 l)
2.11 US gal (8.0 l)
2.64 US gal (10.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON / 86 MON)
Air conditioning system
R-134a refrigerant and special PAG lu-
bricant oil (never R-12)
Windshield washer and
headlamp cleaning system*
6.4 US qt (6.0 l)
MB Windshield Washer Concentrate
1
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing point or MB Windshield Washer Concentrate “S” and commercially available
premixed windshield washer solvent / antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 460).
Page 457 of 506

456 Technical dataFuels, coolants, lubricants, etc.Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air
conditioning system.
Never use R-12 (CFC) or mineral-based
lubricating oil. Otherwise damage to the
system will occur.
Brake fluid
During vehicle operation, the boiling point
of the brake fluid is continuously reduced
through the absorption of moisture from
the atmosphere. Under extremely strenu-
ous operating conditions, this moisture
content can lead to the formation of bub-
bles in the system, thus reducing the sys-
tem’s efficiency.
Therefore, the brake fluid must be re-
placed every two years, preferably in the
spring.
Only brake fluid approved by
Mercedes-Benz is recommended. Your
authorized Mercedes-Benz Center will pro-
vide you with additional information.
Premium unleaded gasoline
!To maintain the engine’s durability and
performance, premium unleaded gaso-
line must be used. If premium unleaded
is not available and low octane fuel is
used, follow these precautions:
Have the fuel tank only partially
filled with unleaded regular and fill
up with premium unleaded as soon
as possible.
Avoid full throttle driving and abrupt
acceleration.
Do not exceed an engine speed of
3 000 rpm if the vehicle is loaded
with a light load such as two per-
sons and no luggage.
Do not exceed
2/3 of maximum ac-
celerator pedal position if the vehi-
cle is fully loaded or operating in
mountainous terrain.
Page 466 of 506

465 Technical terms
Restraint systems
Seat belts, child restraints, lower an-
chors and tethers for children (LATCH).
As independent systems, their protec-
tive functions complement one anoth-
er.
Rim
(
page 337)
Roll bars
Occupant protection system which
consists of tubular steel, integrated in
the rear head restraints. The roll bars
are lowered into the car body during
normal driving conditions and raised
automatically in an accident or in a crit-
ical driving situation.RON
(R
esearch O
ctane N
umber)
The Research Octane Number for gaso-
line as determined by a standardized
method. It is an indication of a gaso-
line's ability to resist undesired detona-
tion (knocking). The average of both
the ->MON (Motor Octane Number)
and RON (Research Octane Number) is
posted at the pump, also known as
ANTI-KNOCK INDEX.
Shift lock
When the vehicle is parked, this lock
prevents the gear selector lever from
being inadvertently moved out of
positionP without SmartKey turned
and brake pedal depressed.
Sidewall
(
page 337)Soft top
Soft top roof that can be opened by
pulling and closed by pressing a switch
and stored in the soft top compartment
in the trunk area.
Speedshift (CLK 500, CLK 55 AMG)
Steering wheel gearshift control. You
can change the gears yourself with the
steering wheel gearshift buttons.
SRS
(S
upplemental R
estraint S
ystem)
Air bags, air bag control unit (with
crash sensor), emergency tensioning
device. Though independent systems,
they are closely interfaced to provide
effective occupant protection.