2003 MERCEDES-BENZ CLK320 COUPE engine

354 Technical dataFuels, coolants, lubricants, etc.Premium unleaded gasoline
Fuel requirements
Only use premium unleaded gasoline
meeting ASTM standard D 439:

The octane number (posted at the
pu mp ) m us t b e 91 mi n. It is an a ve ra ge
of both the Research (R) octane num-
ber and the Motor (M) octane number:
(R+M) / 2). This is also known as the
ANTI-KNOCK INDEX.
Unleaded gasoline containing oxygenates
such as ethanol, IPA, IBA and TBA can be
used provided the ratio of any one of these
oxygenates to gasoline does not exceed
10%; MTBE not to exceed 15%.
The ratio of methanol to gasoline must not
exceed 3% plus additional cosolvents.
Using mixtures of ethanol and methanol is
not allowed. Gasohol, which contains 10%
ethanol and 90% unleaded gasoline, can be
used.
These blends must also meet all other fuel
requirements, such as resistance to spark
knock, boiling range, vapor pressure, etc.
Gasoline additives
A major concern among engine manufac-
turers is carbon build-up caused by gaso-
line. Mercedes-Benz recommends only the
use of quality gasoline containing additives
that prevent the build up of carbon depos-
its.
After an extended period of using fuels
without such additives, carbon deposits
can build up especially on the intake valves
and in the combustion area, leading to en-
gine performance problems such as:

Warm-up hesitation


Unstable idle


Knocking/pinging


Misfire


Power loss
Do not blend any specific fuel additives
with fuel. This only results in unnecessary
cost and may be harmful to the engine op-
eration.
!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
3000 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.

355 Technical data
Fuels, coolants, lubricants, etc.
Damage or malfunctions resulting from
poor fuel quality or from blending specific
fuel additives are not covered by the
Mercedes-Benz Limited Warranty.Coolants
The engine coolant is a mixture of water
and anticorrosion / antifreeze, which pro-
vides:

Corrosion protection


Freeze protection


Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -22°F (-30°C) and corro-
sion protection.
If the antifreeze mixture is effective to
-22°F (-30°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).To provide important corrosion protection,
the solution must be at least 45% anticor-
rosion/antifreeze (equivalent to freeze
protection to approx. - 22°F [-30°C]). If
you use a solution that is more than 55%
anticorrosion/antifreeze (freeze protec-
tion to approx. - 49°F [-45°C]), the engine
temperature will increase due to the lower
heat transfer capability of the solution.
Therefore, do not use more than this
amount of anticorrosion/antifreeze.
If the coolant level is low, water and MB
Anticorrosion /Antifreeze should be used
to bring it up to the proper level (have cool-
ing system checked for signs of leakage).
Please make sure that the mixture is in ac-
cordance with label instructions.The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality, con-
sult your authorized Mercedes-Benz
Center.
The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. You should have it replaced every 15
years or 150 000 miles (250 000 km),
whichever comes first.
Coolant system design and coolant used
stipulate the replacement interval. The
above replacement interval is only applica-
ble if MB 325.0 anticorrosion/antifreeze
solution or other Mercedes-Benz approved
products of equal specification (see Facto-
ry Approved Service Products pamphlet)
are used to renew the coolant concentra-
tion or bring it back up to the proper level.

356 Technical dataFuels, coolants, lubricants, etc.Anticorrosion/antifreeze
Your vehicle contains a number of alumi-
num parts. The use of aluminum compo-
nents in motor vehicle engines
necessitates that anticorrosion/antifreeze
coolant used in such engines be specifical-
ly formulated to protect the aluminum parts. (Failure to use such anticorro-
sion/antifreeze coolant will result in a sig-
nificantly shortened service life.)
Therefore, the following product is strongly
recommended for use in your vehicle:
Mercedes-Benz Mercedes-Benz 325.0 An-
ticorrosion/Antifreeze AgentBefore the start of the winter season (or
once a year in hot southern regions), you
should have the anticorrosion/antifreeze
concentration checked. The coolant is also
regularly checked each time you bring your
vehicle to your authorized Mercedes-Benz
Center for service.
Anticorrosion/antifreeze quantityModel
Approx. freeze protection– 35°F (– 37°C)
– 49°F (– 45°C)
CLK 320
5.3 US qt (5.0 l)
5.9 US qt (5.5 l)
CLK 500
6.4 US qt (6.0 l)
7.0 US qt (6.6 l)
CLK 55 AMG
6.4 US qt (6.0 l)
7.0 US qt (6.6 l)

357 Technical data
Fuels, coolants, lubricants, etc.
Windshield and headlamp washer system
Both the windshield and headlamp washer
systems are supplied from the windshield
washer fluid reservoir.
The washer fluid reservoir has a capacity of
approx.

6.4 US qt. (6.0 l) in vehicles with head-
lamp cleaning system* or heated reser-
voir.

Refill the reservoir with MB Windshield
Washer Concentrate and water (or con-
centrate and commercially available
premixed windshield washer
solvent / antifreeze, depending on am-
bient temperatures).Windshield and headlamp washer fluid
mixing ratio
For temperatures above freezing use
MB Windshield Washer Concentrate “S”
and water:


1 part “S” to 100 parts water
[40 ml “S” to 1 gallon (4 l) water].
For temperatures below freezing use
MB Windshield Washer Concentrate “S”
and commercially available premixed
windshield washer solvent / antifreeze:


1 part “S” to 100 parts solvent
[40 ml “S” to 1 gallon (4 l) solvent].
Warning!
G
Washer solvent/antifreeze is highly flamma-
ble. Do not spill washer solvent/antifreeze
on hot engine parts, because it may burn.
You can be seriously burned.

363 Technical terms
Engine number
The number set by the manufacturer
and placed on the cylinder block to
uniquely identify each engine pro-
duced.
Engine oil viscosity
Measurement for the inner friction (vis-
cosity) of the oil at different tempera-
tures. The higher the temperature an
oil can tolerate without becoming thin,
or the lower the temperature it can tol-
erate without becoming viscous, the
better the viscosity.
ESP
(E
lectronic S
tability Pr
ogram)
Improves vehicle handling and direc-
tional stability.
ETD
(E
mergency T
ensioning D
evice)
Device which deploys in certain frontal
and rear collisions exceeding the sys-
tem's threshold to tighten the seat
belts.
->SRSFSS
(F
lexible S
ervice S
ystem)
Service indicator in the multifunction
display that informs the driver when
the next vehicle maintenance service is
due.
Gear range
Number of gears which are available to
the automatic transmission for shifting.
The automatic gear shifting process
can be adapted to specific operating
conditions using the selector lever.
GPS
(G
lobal P
ositioning S
ystem)
Satellite-based system for relaying
geographic location information to and
from vehicles equipped with special re-
ceivers. Employs CD digital maps for
navigation.
Instrument cluster
The displays and indicator/warning
lamps in the driver’s field of vision, in-
cluding the tachometer, speedometer,
engine temperature and fuel gauge.KEYLESS-GO*
System for entering and operating the
vehicle without the use of a key.
Kickdown
Depressing the accelerator past the
point of resistance shifts the transmis-
sion down to the lowest possible gear.
This very quickly accelerates the vehi-
cle and should not be used for normal
acceleration needs.
Line of fall
The direct line that an object moves
downhill when influenced by the force
of gravity alone.
Lock button
Button on the door which indicates
whether the door is locked or un-
locked. Pushing the lock button down
on an individual door from inside will
lock that door.

364 Technical termsMemory function*
Used to store three individual seat,
steering wheel and mirror positions for
each key or, if so equipped, KEY-
LESS-GO* feature.
Menu
The control system displays are ar-
ranged in menus. Each menu contains
a number of commands for particular
systems. In the Audio menu, for exam-
ple, you will find the commands
Select
radio station
or Operate CD player
.
Using commands you can directly
change the settings for your vehicle.
MON
(M
otor O
ctane N
umber)
The Motor Octane Number for gasoline
as determined by a standardized meth-
od. It is an indication of a gasoline's
ability to resist undesired detonation
(knocking). The average of both the
MON (Motor Octane Number) and
->RON (Research Octane Number) is
posted at the pump, also known as AN-
TI-KNOCK INDEX.Multifunction display
Display field in the speedometer used
to present information provided by the
control system.
Multifunction steering wheel
Steering wheel with buttons for operat-
ing the control system.
Overspeed range
Engine speeds within the red marking
of the tachometer dial. Avoid this en-
gi ne sp ee d ra nge , a s it m ay re su lt i n s e-
rious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Parktronic*
System which uses visual and acoustic
signals to assist the driver during park-
ing maneuvers.
Poly-V-belt drive
Drives engine-components (alternator,
AC compressor, etc.) from the engine.Power train
Collective term designating all compo-
nents used to generate and transmit
motive power to the drive axles, includ-
ing


engine


clutch/torque converter


transmission


transfer case


drive shaft


differential


axle shafts/axles
Program mode selector switch
Used to switch the automatic transmis-
sion between regular operationS and
winter operationW.
CLK 55 AMG with steering wheel gear-
shift control and manual shift program.
In addition toS andC (for regularS or
comfortC operation, see above) you
can use theM for manual shift
program.

365 Technical terms
Remote Vehicle Diagnostics
Transmission of vehicle data and cur-
rent location to the Mercedes-Benz
Customer Assistance Center for sub-
scribers to Tele Aid service.
REST
(Residual engine heat utilization)
Feature that uses the engine heat
stored in the coolant to heat the vehi-
cle interior for a short time after the en-
gine has been turned off.
Restraint systems
Seat belts, belt tensioners, airbags and
child restraint systems. As indepen-
dent systems, their protective func-
tions complement one another.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 transmission selector le-
ver from being inadvertently moved out
of positionP without key turned and
brake pedal depressed.
Speedshift
Steering wheel gearshift control and
manual shift program. In the manual
shift program mode you can change
the gears yourself on the steering
wheel or by using the selector lever.
SRS
(S
upplemental R
estraint S
ystem)
Seat belts, emergency tensioning de-
vice and airbags. Though independent
systems, they are closely interfaced to
provide effective occupant protection.

367 Index
A
ABS 23, 74, 361
ABS control 75
Malfunction indicator lamp 277
Messages in display 284
Warning lamp 277
Accelerator position, automatic transmis-
sion 146
Accident
In case of 49
Activating
Air conditioning (cooling) 163
Air recirculation mode 160
Anti-theft alarm system 80
Automatic climate control 155
Central locking (control system) 133
Charcoal filter 161
Distance warning function* 205
Distronic* 201
Easy-entry/exit feature 133
ESP 78
Exterior headlamps 46
Exterior lamps 106
Front and rear fog lamp 106
Hazard warning flasher 108
Headlamps 46High beams 108
Ignition 31
Ignition with KEYLESS-GO* start/stop
button 33
Immobilizer 51, 79
Rear window defroster 162
Residual heat 163
Seat heater* 101
Tow-away alarm 81
Windshield wipers 48
Activating steering wheel gearshift control
147
Downshifting 148
Upshifting 147
Adding
Coolant 257
Engine oil 255
Additional turn signals 317
Adjustable air vents, rear passenger com-
partment 164Adjusting 34
Air distribution 158
Air volume 159
Backrest tilt 36
Exterior rear view mirror 38
Head restraint height 36
Head restraint tilt 36
Inside rear view mirror 38
Instrument cluster illumination 111
Mirrors 38
Multicontour seat* 100
Seat cushion depth 100
Seat cushion tilt 36
Seat fore and aft adjustment 35
Seat height 35
Seats 34
Steering column height 38
Steering column length 38
Steering wheel 37
Air conditioning (cooling)
Turning off 163
Turning on 163
Air conditioning refrigerant 353
Air distribution
Adjusting 158