Page 360 of 464

360 Practical hintsWhat to do if …When the message
Add 1 qt.
(Canada:
1 liter
) engine oil when next
refueling (SLK 55 AMG) or
Check oil
level when next refueling (SLK 350)
appears while the engine is running and at
operating temperature, the engine oil level
has dropped to approximately the
minimum level.When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.
Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest ser-
vice station where the engine oil should be
topped to the required level with an ap-
proved oil specified in the Factory
Approved Service Products pamphlet.
Display symbol
Display message
Possible cause
Possible solution
:
USA only:Add 1 qt. engine oil
when next refuelingCanada only:Add 1 liter engine oil
when next refueling
SLK 55 AMG only:
The engine oil level is too low.
Add engine oil (
page 292) and check the
engine oil level (page 288).
Check oil level
when next refueling
SLK 350 only:
The engine oil level has dropped to
a critical level.
Check the engine oil level (
page 288) and
add engine oil as required (page 292).
If you must add engine oil frequently, have
the engine checked for possible leaks.
!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Page 361 of 464
361 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
:
Engine oil level
Stop, engine off
SLK 55 AMG only:
There is no oil in the engine. There
is a danger of engine damage.
Carefully bring the vehicle to a halt as soon
as possible.
Turn off the engine.
Add engine oil (
page 292) and check the
engine oil level (page 288).
Engine oil level
Visit workshop
SLK 55 AMG only:
The measuring system is malfunc-
tioning.
Have the measuring system checked by an
authorized Mercedes-Benz Center.
Engine oil level
Reduce oil level
SLK 55 AMG only:
You have added too much engine
oil. There is a risk of damaging the
engine or the catalytic converter.
Have oil siphoned or drained off.
Observe all legal requirements with respect
to its disposal.
Engine oil
Visit workshop
SLK 55 AMG only:
There may be water in the engine
oil.
Have the engine oil checked.
Page 382 of 464
382 Practical hintsReplacing bulbsNotes on bulb replacement
Only use 12-volt bulbs of the same type
and with the specified watt rating.
Switch lights off before changing a bulb
to prevent short circuits.
Always use a clean lint-free cloth when
handling bulbs.
Your hands should be dry and free of oil
and grease.
If the newly installed bulb does not
come on, visit an authorized
Mercedes-Benz Center.Have the LEDs and bulbs for the following
lamps replaced by an authorized
Mercedes-Benz Center:
Additional turn signal lamps in the
exterior rear view mirrors
Bi-Xenon* lamps
Front fog lamps
High mounted brake lamp
Brake lamps
Front and rear side marker lamps
Parking/standing lamps in the tail
lamp assemblies
Replacing bulbs for front lamps
Before you start to replace a bulb for a
front lamp, do the following first:
Turn the exterior lamp switch to
positionM (
page 106).
Open the hood (
page 287) (except
for side marker lamps).
iHave the headlamp adjustment
checked regularly.
Page 392 of 464
392 Practical hintsFlat tire
Guide the spare wheel onto the align-
ment bolt and push it on.
Insert the wheel bolts and tighten them
slightly.
Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.
Warning!
G
Always replace wheel bolts that are dam-
aged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be re-
paired immediately. Do not continue to drive
under these circumstances! Contact an au-
thorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect wheel bolts or improperly tight-
ened wheel bolts can cause the wheel to
come off. This could cause an accident. Be
sure to use the correct wheel bolts.
Warning!
G
Use only genuine equipment
Mercedes-Benz wheel bolts. Other wheel
bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise the vehicle
could fall off the jack.
Page 422 of 464

422 Technical dataFuels, coolants, lubricants, etc.CapacitiesVehicle components and their respective
lubricants must match. Therefore, only use
products tested and approved by
Mercedes-Benz.Please refer to the Factory Approved Ser-
vice Products pamphlet, or inquire at your
authorized Mercedes-Benz Center.
Model
Capacity
Fuels, coolants, lubricants etc.
Engine with oil filter
SLK 350
8.5 US qt (8.0 l)
Approved engine oils
SLK 55 AMG
8.5 US qt (8.0 l)
Automatic transmission*
SLK 350
10.4 US qt (9.8 l)
MB Automatic Transmission Fluid
SLK 55 AMG
10.4 US qt (9.8 l)
Manual transmission
SLK 350
1.6 US qt (1.5 l)
MB Manual Transmission Oil
Rear axle
SLK 350
1.2 US qt (1.1 l)
Hypoid gear oil SAE 85 W 90
SLK 55 AMG
1.3 US qt (1.2 l)
Power steering
SLK 350
1.1 US qt (1.0 l)
MB Power Steering Fluid (Pentosin CHF 11S)
SLK 55 AMG
1.1 US qt (1.0 l)
Front wheel hubs
approx. 2.1oz (60g) each
High temperature roller bearing grease
Brake system
0.5 US qt (0.5 l)
MB Brake Fluid (DOT 4)
Cooling system
SLK 350
approx.11.2 US qt (10.2 l)
MB 325.0 Anticorrosion/Antifreeze Agent
SLK 55 AMG
approx. 11.7 US qt (11.1 l)
Page 423 of 464
423 Technical data
Fuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants etc.
Fuel tank
including a reserve of
SLK 350
SLK 55 AMG
approx. 18.5 US gal (70.0 l)
approx. 2.4 US gal (9.0 l)
approx. 18.5 US gal (70.0 l)
approx. 2.6 US gal (10.0 l)
Premium unleaded gasoline:
Minimum posted Octane 91 (average of
96 RON / 86 MON)
Air conditioning system
R-134a refrigerant and special PAG lubricant oil
(never R-12)
Hydraulic system for
retractable hardtop
0.19 US qt (0.18 l)
MB Hydraulic Fluid
Windshield washer
system and headlamp
cleaning system*
7.4 US qt (7.0 l)
MB Windshield washer concentrate
1
1Use MB Windshield Washer Concentrate“S” and water for temperatures above freezing point or MB Windshield Washer Concentrate “S” and commercially available
premixed windshield washer solvent/antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 429).
Page 424 of 464

424 Technical dataFuels, coolants, lubricants, etc.Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, only use
approved engine oils and oil filters re-
quired for vehicles with Maintenance
System (U.S. vehicles) or FSS (Canada
vehicles). For a listing of approved engine
oils and oil filters, refer to the Factory
Approved Service Products pamphlet, or
contact an authorized Mercedes-Benz
Center.
Using engine oils and oil filters of specifica-
tion other than those expressly required
for the Maintenance System (U.S. vehi-
cles) or FSS (Canada vehicles), or changing
of oil and oil filter at change intervals long-
er than those called for by the
Maintenance System (U.S. vehicles) or
FSS (Canada vehicles) will result in engine
damage not covered by the
Mercedes-Benz Limited Warranty.Please follow Maintenance System (U.S.
vehicles) or FSS (Canada vehicles) recom-
mendations for scheduled oil changes.
Failure to do so will result in engine dam-
age not covered by the Mercedes-Benz
Limited Warranty.
Engine oil additives
Do not blend oil additives with engine oil.
They may damage the engine. Damage or
malfunctions resulting from blending oil
additives are not covered by the
Mercedes-Benz Limited Warranty.Air conditioning refrigerant
R-134a (HFC) refrigerant and special
PAG lubricating oil are used in the air con-
ditioning 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, prefera-
bly in the spring. Only brake fluid approved
by Mercedes-Benz is recommended. Your
authorized Mercedes-Benz Center will pro-
vide you with additional information.
Page 425 of 464

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.