482 Technical dataFuels, coolants, lubricants, etc.Premium unleaded gasoline
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.
Warning!
G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
injury. Whenever you are around gasoline,
avoid inhaling fumes and skin contact, extin-
guish all smoking materials. Never allow
sparks, flame or smoking materials near
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.
483 Technical data
Fuels, coolants, lubricants, 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 other 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.
484 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.
485 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 350
3.75 US qt (3.55 l)
4.1 US qt (3.9 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)
486 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.
488 Technical termsCruise control
Driving convenience system for auto-
matically maintaining the vehicle speed
set by the driver.
Curb weight
(
page 355)
DOT
(Department O
f Transportation)
(
page 355)
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
®(Electronic 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 355)
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 355)
GVWR
(Gross V
ehicle W
eight R
ating)
(
page 356)
490 Technical termsMOE
(M
ercedes-Benz O
riginal E
xtended
equipment tires)
Tires with limited run-flat characteris-
tics. The MOExtended system allows
you to continue driving your vehicle
even if there is a total loss of pressure
in one or more tires.
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.
Normal occupant weight
(
page 356)
OCS
(Occupant C
lassification S
ystem)
The system automatically turns the
front passenger front air bag on or off
based on the classified occupant size
category determined by weight sensor
readings from the seat.Overspeed range
Engine speeds within the red marking
on the tachometer dial. Avoid this en-
gine speed range, as it may result in se-
rious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Poly-V-belt drive
Drives engine-components (alternator,
AC compressor, etc.) from the engine.
Power train
Collective term designating all
components used to generate and
transmit motive power to the drive
axles, including
engine
clutch/torque converter
transmission
transfer case
drive shaft
differential
axle shafts/axlesProduction options weight
(
page 356)
Program mode selector switch
Used to switch the automatic transmis-
sion between regular operationS and
comfort operationC.
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.
PSI
(Pounds per S
quare I
nch)
(
page 356)
Recommended tire inflation pressure
(page 356)
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.
494 IndexAutomatic transmission 166
Accelerator position 170
Emergency operation
(Limp Home Mode) 180
Gear ranges 171
Gear selector lever 48, 166
Gear selector lever position 166, 168
Gear selector lever,
One-touch gearshifting 173
Gear shifting malfunctions 180
Kickdown 170
Manual (One touch) gearshifting 173
Manual shift program 178
One-touch gearshifting, Steering
wheel gearshift control 174
Shift program mode
selector switch 172, 178
Starting engine 48
Transmission fluid level 326
Automatic Transmission Fluid see ATF
B
Backrest
Seat, Multicontour* 121
Seat, Power 38Backup lamps
Messages in display 406
Replacing bulbs 438, 439
Bar 355
BAS 88, 487
Batteries, SmartKey
Changing 436
Checking battery condition 99
Batteries, SmartKey with KEYLESS-GO*
Changing 437
Checking battery condition 105
Battery, Vehicle 328, 453
Charging 455
Connecting 455
Disconnecting 454
Installing 455
Jump starting 456
Messages in display 395
Removing 454
Bead 355
Beverage holder see Cup holder
Bi-Xenon headlamps* see Headlamps
Block heater (Canada only) 360
Bolts, Spare wheel 418
Brake Assist System see BASBrake fluid 481
Checking 320
Messages in display 396
Brake lamp
Cleaning lenses 369
High mounted 439
Messages in display 404
Replacing bulbs 439, 443
Brake pads
Messages in display 396
Brakes 308
High-performance brake system
(CLK 55 AMG only) 309
Warning lamp 375
Break-in the vehicle 306
Bulbs, replacing see Replacing bulbs
C
CAC 487
California retail buyers and lessees,
Important notice for 11
Call priority (Tele Aid) 294
Can holder see Cup holder
CAN system 487
Capacities and
recommended fuels/lubricants 479
Cargo area see Trunk