2005 MERCEDES-BENZ CLK320 CABRIOLET Owner's Manual

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.

457 Technical data
Fuels, coolants, lubricants, etc.
Fuel requirements
Only use premium unleaded fuel:

The octane number (posted at the
pump) must be 91 min. It is an average
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 lossIn areas where carbon deposits may be en-
countered due to lack of availability of gas-
olines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to Factory
Approved Service Products pamphlet for a
listing of approved product(s). Follow di-
rections on product label.
Do not blend any specific fuel additives
with fuel. This only results in unnecessary
cost and may be harmful to the engine
operation.
Damage or malfunction resulting from
poor fuel quality or from blending addition-
al fuel additives other than those tested
and approved by us for use on
Mercedes-Benz vehicles listed in the
Factory Approved Service Products pam-
phlet are not covered by the
Mercedes-Benz Limited Warranty.

458 Technical dataFuels, coolants, lubricants, etc.Coolants
The engine coolant is a mixture of water
and anticorrosion / antifreeze, which
provides:

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
corrosion protection.
If the antifreeze mixture is effective
to -22°F (-30°C), the boiling point of the
coolant in the pressurized cooling system
is reached at approx. 266°F (130°C).The coolant solution must be used
year-round to provide the necessary corro-
sion protection and increase boil-over pro-
tection. Refer to Maintenance Booklet for
replacement interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable if
MB 325.0 Anticorrosion/Antifreeze solu-
tion 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.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% anti-
corrosion/antifreeze (freeze protection to
approx. -49°F [-45°C]), the engine temper-
ature will increase due to the lower heat
transfer capability of the solution. There-
fore, 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 the mixture is in accor-
dance 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,
consult an authorized Mercedes-Benz
Center.

459 Technical data
Fuels, 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 325.0 Anticorrosion/Anti-
freeze agent.Before 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 an 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)

460 Technical dataFuels, coolants, lubricants, etc.Windshield washer system and headlamp cleaning system*
Both the windshield washer and headlamp
cleaning system are supplied from the
windshield washer fluid reservoir.
The washer fluid reservoir has a capacity of
approx. 6.4 US qt (6.0 l).

Refill the reservoir with MB Windshield
Washer Concentrate “S” and water (or
concentrate and commercially avail-
able premixed windshield washer
solvent / antifreeze, depending on
ambient temperatures).Windshield and headlamp washer fluid
mixing ratio
For temperatures above freezing point, use
MB Windshield Washer Concentrate “S”
and water:


1 part “S” to 100 parts water
(1.34 fl oz [40 ml] “S” to 1 gallon [4.0 l]
water)
For temperatures below freezing point, use
MB Windshield Washer Concentrate “S”
and commercially available premixed
windshield washer solvent / antifreeze:


1 part “S” to 100 parts solvent
(1.34 fl oz [40 ml] “S” to 1 gallon [4.0 l]
solvent)
Warning!
G
Washer solvent/antifreeze is highly flam-
mable. Do not spill washer
solvent/antifreeze on hot engine parts, be-
cause it may ignite and burn. You could be
seriously burned.

461 Technical terms
ABS
(A
ntilock B
rake S
ystem)
Prevents the wheels from locking up
during braking so that the vehicle can
continue to be steered.
Accessory weight
(
page 335)
Air pressure
(page 335)
Alignment bolt
Metal pin with thread. The centering
pin is an aid used when changing a tire
to align the wheel with the wheel hub.
Aspect ratio
(page 335)
Bar
(page 336)
BAS
(Brake A
ssist S
ystem)
System for potentially reducing braking
distances in emergency braking situa-
tions. The system is activated when it
senses an emergency based on how
fast the brake is applied.Bead
(
page 336)
Bi-Xenon headlamps*
Headlamps which use an electric arc as
the light source and produce a more in-
tense light than filament headlamps.
Bi-Xenon headlamps produce low
beam and high beam.
CAC
(Customer A
ssistance C
enter)
Mercedes-Benz customer service cen-
ter, which can help you with any ques-
tions about your vehicle and provide
assistance in the event of a break-
down.
CAN system
(C
ontroller A
rea N
etwork)
Data bus network serving to control ve-
hicle functions such as door locking or
windshield wiping.Cockpit
All instruments, switches, buttons and
indicator/warning lamps in the passen-
ger compartment needed for vehicle
operation and monitoring.
Cold tire inflation pressure
(
page 336)
COMAND
(Cockpit M
anagement and D
ata Sys-
tem)
Information and operating center for
vehicle sound and communications
systems, including the radio and the
navigation system, as well as other op-
tional equipment (CD changer*, tele-
phone, etc.).
Control system
The control system is used to call up
vehicle information and to change
component settings. Information and
messages appear in the multifunction
display. The driver uses the buttons on
the multifunction steering wheel to
navigate through the system and to ad-
just settings.

462 Technical termsCruise control
Driving convenience system for auto-
matically maintaining the vehicle speed
set by the driver.
Curb weight
(
page 336)
DOT
(Department O
f Transportation)
(
page 336)
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.
->SRS
FSS (Canada vehicles)
(F
lexible S
ervice S
ystem)
Maintenance service indicator in the
multifunction display that informs the
driver when the next vehicle mainte-
nance service is due. FSS evaluates en-
gine temperature, oil level, vehicle
speed, engine speed, distance driven
and the time elapsed since your last
maintenance service, and calls for the
next maintenance service accordingly.GAWR
(G
ross A
xle W
eight R
ating)
(
page 336)
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 gear selector le-
ver.
GPS
(Global 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.
GVW
(G
ross V
ehicle W
eight)
(
page 336)
GVWR
(Gross V
ehicle W
eight R
ating)
(
page 336)

463 Technical terms
Head-thorax air bag
Installed in the driver and the front pas-
senger seat, these air bags protect oc-
cupants during side impact collisions
exceeding a preset threshold. Unlike
normal side impact air bags,
head-thorax air bags are also designed
to provide protection for the head area.
Instrument cluster
The displays and indicator/warning
lamps in the driver’s field of vision, in-
cluding the tachometer, speedometer,
coolant temperature indicator and fuel
display.
KEYLESS-GO*
System for entering and operating the
vehicle without the use of a SmartKey.
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.Kilopascal (kPa)
(
page 336)
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.
Maintenance System (U.S. vehicles)
Maintenance service indicator in the
multifunction display that informs the
driver when the next vehicle mainte-
nance service is due. The Maintenance
System in your vehicle tracks distance
driven and the time elapsed since your
last maintenance service, and calls for
the next maintenance service
accordingly.
Maximum load rating
(page 337)
Maximum loaded vehicle weight
(page 337)
Maximum tire inflation pressure
(page 337)Memory function*
Used to store three individual seat,
steering wheel and mirror positions for
each SmartKey or, if so equipped,
KEYLESS-GO* feature.
Menu
The control system displays are ar-
ranged in menus. Each menu contains
a number of commands for particular
systems.
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
ANTI-KNOCK INDEX.
Multifunction display
Display field in the speedometer used
to present information provided by the
control system.