425 Technical data
Fuels, 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.
Gasoline additives
A major concern among engine manufac-
turers is carbon build-up caused by gaso-
line. Mercedes-Benz only recommends 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
engine performance problems such as:
Warm-up hesitation
Unstable idle
Knocking/pinging
Misfire
Power loss
!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
2/3of maximum ac-
celerator pedal position if the vehi-
cle is fully loaded or operating in
mountainous terrain.
426 Technical dataFuels, coolants, lubricants, etc.In areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to the
Factory Approved Service Products pam-
phlet for a listing of approved product(s).
Follow directions on product label.
Do not blend any specific fuel additives
with fuel. This only results in unnecessary
costs and may be harmful to engine opera-
tion.
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
pamphlet 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).
The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. Refer to Maintenance Booklet for in-
formation on replacement intervals.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
Factory Approved Service Products
pamphlet) are used to renew the coolant
concentration 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.
427 Technical data
Fuels, coolants, lubricants, etc.
If the coolant level is low, water and
MB Anticorrosion/Antifreeze should be
used to bring it up to the proper level (have
cooling system checked for signs of leak-
age). Please make sure the mixture is in
accordance 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 an authorized Mercedes-Benz Center.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
significantly shortened service life.)
Therefore, the following product is strongly
recommended for use in your vehicle:
Mercedes-Benz 325.0
anticorrosion/antifreeze 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.
428 Technical dataFuels, coolants, lubricants, etc.Anticorrosion/antifreeze quantityModel
Approx. freeze protection–35°F (–37°C)
–49°F (–45°C)
SLK 350
5.4 US qt (5.1 l)
6.0 US qt (5.6 l)
SLK 55 AMG
5.9 US qt (5.5 l)
6.4 US qt (6.1 l)
429 Technical data
Fuels, coolants, lubricants, etc.
Windshield washer system and head-lamp cleaning system*
Both the windshield washer system and
the headlamp cleaning system* are sup-
plied from the windshield washer fluid res-
ervoir.
The washer fluid reservoir has a capacity of
approximately 7.4 US qt (7.0 l).
Refill the reservoir with MB Windshield
Washer Concentrate “S” and water (or
concentrate and commercially avail-
able premixed windshield washer sol-
vent/antifreeze, depending on ambient
temperatures).Windshield washer and headlamp
cleaning* fluid mixing ratio
For temperatures above freezing point, use
MB Windshield Washer Concentrate “S”
and water:
1 part “S” to100 parts water
[40 ml (1.34 fl oz) “S” to 1 gallon (4 l)
water]
For temperatures below freezing point, use
MB Windshield Washer Concentrate “S”
and commercially available premixed
windshield washer solvent/antifreeze:
1part“S” to 100parts solvent
[40 ml (1.34 fl oz) “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 ignite
and burn. You could be seriously burned.
433 Technical terms
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 323)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.
GVW
(G
ross V
ehicle W
eight)
(
page 323)
GVWR
(Gross V
ehicle W
eight R
ating)
(
page 324)Head-thorax air bag
Installed in the doors, these air bags
protect occupants during side impact
collisions exceeding a preset thresh-
old. Unlike normal side 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 and fuel gauge.
Kickdown
Depressing the accelerator past the
point of resistance shifts the automatic
transmission down to the lowest possi-
ble gear. This very quickly accelerates
the vehicle and should not be used for
normal acceleration needs.
Kilopascal (kPa)
(
page 324)
435 Technical terms
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
Production options weight
(
page 324)Program mode selector switch
Used to switch the automatic transmis-
sion between standard operation (S)
and comfort operation (C).
Vehicles with steering wheel gearshift
control and manual shift program: in
addition toS andC (for regularS
or comfortC operation, see above),
you can useM for manual shift pro-
gram.
PSI
(P
ounds per s
quare i
nch)
(
page 324)
Recommended tire inflation pressure
(page 324)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, air bags
and child restraint systems. As inde-
pendent systems, their protective func-
tions complement one another.
Rim
(
page 324)
Retractable hardtop
Hardtop that can be opened and closed
at the push of a button and stored in
the trunk.
441 Index
Bi-Xenon
Description 431
Headlamps 381
Bolts
For spare wheel 373
Brake Assist System see BAS
Brakes 274
Brake fluid 286, 424
Display message 356
Salty roads 274
SLK 55 AMG 275
Warning lamp 343
Break-in period 272
Bulbs
Front/rear lamps 380
Replacing 380
Buttons (Audio system) 194C
CAC 431
California, important notice 11
CAN system, description 432
Capacities
(Fuels, coolants, lubricants, etc.) 422
Catalytic converter 282
CD
Changer 250
Player/changer, operation 125
CD changer (Audio system) 207, 209
CD operation (Audio system) 207
Center console
Lamp 347
Overview 28
Central locking
Automatic (Control system) 141
Automatic (When driving) 97
From outside (SmartKey) 59
Locking/unlocking from inside 97
Central locking/unlocking switches 98
Certification label 410
CHECK ENGINE indicator lamp 344Child safety
Air bags 64
Children in the vehicle 73
Cigarette lighter 254
Cleaning tires 299
Climate control 172
Air conditioning 178
Air distribution 176
Air recirculation mode 176
Air volume 176
Control panel, overview 175
Defrosting 181
Maximum cooling 179
Rear window defroster 171
Switching on/off 175
Temperature 175
Clock 116
Cockpit
Description 432
Overview 22
Cold tire inflation pressure 323
Collapsible tire, description 432
Collapsible wheel chock 371