450 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
replaced every two years, preferably in the
spring.
Only brake fluid approved by
Mercedes-Benz is recommended. Your
authorized Mercedes-Benz Center will
provide 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.
451 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.
452 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 corro-
sion 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.
453 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 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 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)
454 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.
455 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.
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.BAS
(B
rake 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.
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
(C
ustomer 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.
469 Index
E
Easy-entry/exit feature 112
Activating 159
Electrical fuses 429
Electrical outlet in
rear passenger compartment 278
Electrical system
Technical data 444
Electronic Stability Program see ESP
Emergency call
911 245
Emergency call system* 280
Emergency calls
Initiating an emergency call 282
With Tele Aid 281
Emergency operation
(Limp Home Mode) 177
Emergency operations
Closing
power tilt/sliding sunroof* 401
Locking the vehicle 398
Opening
power tilt/sliding sunroof* 401
Remote door unlock 286
Unlocking the vehicle 397Emergency tensioning device see ETD
Emission control 304
Emission control information label 436
Ending
A call (telephone) 163
Engine
Compartment 308
Message in display 356
Starting 47
Starting with KEYLESS-GO* 47
Starting with the SmartKey 47
Technical data 438
Turning off 56
Engine cleaning 349
Engine compartment 308
Fuse box in 431
Hood 308
Engine malfunction
indicator lamp 25, 356
Engine number 436, 456Engine oil 309, 449
Adding 312
Additives 449
Checking level 310
Consumption 309
Filler cap 312
Filler neck 312
Message in display 379
Messages in display 311
Viscosity 456
Engine oil level see Oil level
ESP 25, 86, 456
Messages in display 367
Switching off 87
Switching on 88
Warning lamp 358
ETD 69, 456
Safety guidelines 64
Exterior lamp switch 124
Exterior rear view mirrors
Adjusting 41
Parking position for 160
470 IndexF
Fahrenheit
Setting temperature units 149
Fastening the seat belts 43
Fine adjustment
Cruise control 259
First aid kit 389
Flat tire 412
Collapsible tire
(CLK 55 AMG only) 394
Lowering the vehicle 418
Minispare wheel
(except CLK 55 AMG) 393
Mounting the spare wheel 413
Preparing the vehicle 412
Flexible Service System (Canada vehicles)
see Maintenance service system
Flexible Service System (FSS) 456
Floormats*
Removing 278
Installing 278Fog lamp, rear 128, 405
Fog lamps
Replacing bulbs 404
Fog lamps, front
Messages in display 382
Replacing bulbs 405
Switching on 128
Front air bags 65
Front lamps
Messages in display 382–384
Replacing bulbs 404, 406
Switching on 124
Front passenger front
air bag off indicator lamp 77, 360
Front seat head restraints
Installing 114
Power seat 114
Removing 114
Front seats
Seat heating* 119
Ventilation* 120
FSS (Canada vehicles) see
Maintenance service system
FSS (Flexible Service System) 456Fuel 306
Additives 451
Fuel reserve warning lamp 359
Gasoline additives 451
Premium
unleaded gasoline 306, 448, 450
Requirements 451
Reserve warning 25
Technical data 447
Fuel additives 451
Fuel cap
Message in display 356
Fuel consumption statistics
After start 161
Since last reset 161
Fuel filler flap 305
Locking 305
Opening 399
Unlocking 305
Fuel requirements 451
Fuel reserve tank
Message in display 381
Fuel tank
Capacity 448
Filler flap 305