Page 298 of 498
297 Operation
Engine compartment
CLS 500, CLS 55 AMG1Filler cap
Unscrew filler cap1 from filler neck.
Add engine oil as required. Be careful
not to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
For more information on engine oil, see the
“Technical data” section (
page 461) and
(
page 464).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Center
check the transmission.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!Excess oil must be siphoned or drained
off. It could cause damage to the
engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
Page 299 of 498

298 OperationEngine compartment
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.Coolant expansion tank
Using a rag, turn the cap slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning the cap counterclock-
wise and remove it.
The coolant level is correct if the level
for cold coolant: reaches the top of
the mark (plastic bridge) visible
through the filling opening
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information on coolant, see the
“Technical data” section (
page 466).
Warning!
G
In order to avoid any possibly serious burns:
Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.
Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.
Using a rag, slowly open the cap approx-
imately
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out
under pressure.
Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.
Page 301 of 498

300 OperationEngine compartmentWindshield washer system and headlamp cleaning system*
The windshield washer reservoir is located
in the engine compartment.
1Washer fluid reservoir
Fluid for the windshield washer system and
the headlamp cleaning system is supplied
from the windshield washer reservoir. It
has a capacity of approximately 7.4 US qt
(7 l).During all seasons, add MB Windshield
Washer Concentrate “S” to water. Premix
the windshield washer fluid in a suitable
container.
Refill the reservoir with MB Windshield
Washer Concentrate and water (or
commercially available premixed wind-
shield washer solvent/antifreeze, de-
pending on ambient temperatures).
Always use washer solvent/antifreeze
where temperatures may fall below
freezing point. Failure to do so could
result in damage to the washer sys-
tem/reservoir.For more information, see “Windshield and
headlamp washer fluid mixing ratio”
(
page 470).
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.
!Only use washer fluid which is suitable
for plastic lenses. Improper washer flu-
id can damage the plastic lenses of the
headlamps.
Page 337 of 498

336 OperationWinter drivingBefore the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:
Check of anticorrosion and antifreeze
concentration
Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system
Add MB Concentrate “S” to a premixed
windshield washer solvent / antifreeze
which is formulated for temperatures
below freezing point (
page 468).
Battery test
Battery capacity drops with decreasing
ambient temperature. A well charged
battery helps to make sure that the
engine can be started and the
electro-hydraulic brake system will be
fully operational, even at low ambient
temperatures.
Tire change
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Not all M+S rated
tires provide special winter performance.
Make sure the tires you use show the
mountain/snowflake.marking on the
tire sidewall. These tires meet specific
snow traction performance requirements
of the Rubber Manufacturers Association
(RMA) and The Rubber Association of
Canada (RAC) and have been designed
specifically for use in snow conditions. Use
of winter tires is the only way to achieve
the maximum effectiveness of the ABS,
ESP
® and electro-hydraulic brake system
in winter operation.
For safe handling, make sure that all
mounted winter tires are of the same make
and have the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such
notices are available at your tire dealer or
any authorized Mercedes-Benz Center.
Warning!
G
Winter tires with a tread depth of less than 1/6in (4 mm) must be replaced. They are no
longer suitable for winter operation.
Page 379 of 498

378 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
(USA only)ú(Canada only)±
Visit workshop
There may be a malfunction in the:
fuel injection system
ignition system
exhaust system
fuel system
Have the measuring system checked
by an authorized Mercedes-Benz
Center.
B
Coolant
Check level
The coolant level is too low.
Add coolant (
page 297).
If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Center.
Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You can be seriously burned.
!Do not ignore the low engine coolant
level warning. Extended driving with
the message and symbol displayed
may cause serious engine damage not
covered by the Mercedes-Benz Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing major
engine damage.
Page 463 of 498
462 Technical dataFuels, coolants, lubricants etc.
Model
Capacity
Fuels, coolants, lubricants etc.
Power steering
approx. 1.1 US qt (1.0 l)
MB Power Steering Fluid (Pentosin CHF 11S)
Front wheel hubs
approx. 3.0 oz (85 g) each
High temperature roller bearing grease
Brake system
1.1 US qt (1.05 l)
MB Brake Fluid (DOT 4+)
Cooling system
CLS 500
11.9 US qt (11.3 l)
MB 325.0 Anticorrosion/Antifreeze
CLS 55 AMG
13.84 US qt (13.1 l)
MB 325.0 Anticorrosion/Antifreeze
Fuel tank
21.12 US gal (80.0 l)
Premium unleaded gasoline
Minimum Posted Octane 91 (Avg. of 96
RON/86 MON)
including a reserve of
2.38 US gal (9.0 l)
Page 464 of 498
463 Technical data
Fuels, coolants, lubricants etc.
Model
Capacity
Fuels, coolants, lubricants etc.
Air conditioning system
R-134a refrigerant and special PAG lubricant oil
(never R-12)
Windshield washer and head-
lamp 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 or MB Windshield Washer Concentrate “S” and commercially available pre-
mixed windshield washer solvent/antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 470).
Page 467 of 498

466 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 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 costs 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 Fac-
tory Approved Service Products pamphlet
are not covered by the Mercedes-Benz
Limited Warranty.
Fuel requirements
Only use premium unleaded gasoline
meeting ASTM standard D 439.
The octane number (posted at the pump)
m u s t b e 9 1 m i n . I t i s a n a v e r a g e o f b o t h t h e
Research (R) Octane Number and the Mo-
tor (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 must not 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.
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.