Page 297 of 498

296 OperationEngine compartment
If engine is at operating temperature,
wait 5 minutes before repeating check
procedure.
If engine is not at operating tempera-
ture yet, wait 30 minutes before
repeating check procedure.
If you see the message:
Engine oil level
Not when engine on
Turn off the engine.
If the engine is at normal operating
temperature, wait 5 minutes before
checking oil.
If the engine is not yet at normal
operating temperature, you must wait
30 minutes before checking oil.If there is excess engine oil with the engine
at normal operating temperature, the
following message will appear:
Engine oil level
Reduce oil level
Have excess oil siphoned or drained
off. Contact an authorized
Mercedes-Benz Center.
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 382). Adding engine oil!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.
!Only use approved engine oils and oil
filters required for vehicles with Main-
tenance System (U.S. vehicles) or
FSS PLUS (Canada vehicles). For a list-
ing of approved engine oils and oil fil-
ters, refer to the Factory Approved
Service Products pamphlet in your
vehicle literature portfolio, or contact
an authorized Mercedes-Benz Center.
Using engine oils and oil filters of spec-
ification other than those expressly
required for the Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles), or changing of oil and oil filter
at change intervals longer than those
called for by the Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles) will result in engine damage
not covered by the Mercedes-Benz
Limited Warranty.
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 300 of 498

299 Operation
Engine compartment
Battery
Your vehicle is equipped with two batter-
ies:
Auxiliary battery (located in the engine
compartment).
Main battery (starter and electrical
consumers; located in the trunk)
(page 431).
The batteries should always be sufficiently
charged in order to achieve their rated ser-
vice life. Refer to Maintenance Booklet for
battery maintenance intervals.
If you use your vehicle mostly for short-dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion.
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clean
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.
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 302 of 498

301 Operation
Tires and wheels
Tires and wheels
See an authorized Mercedes-Benz Center
for information on tested and recommend-
ed rims and tires for summer and winter
operation. They can also offer advice con-
cerning tire service and purchase.
Important guidelines
Only use sets of tires and rims of the
same type and make.
Tires must be of the correct size for the
rim.
Break in new tires for approximately
60 miles (100 km) at moderate
speeds.
Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire inflation pressure loss and
damage to the tire beads.
If vehicle is heavily loaded, check tire
inflation pressure and correct as re-
quired.
Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:
The wheel brakes or suspension compo-
nents can be damaged
The correct operating clearance of the
wheels and the tires are no longer guar-
anteed
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use Genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on re-
treads. Mercedes-Benz can therefore not
assure the operating safety of the vehicle
when such tires are used.
Page 303 of 498

302 OperationTires and wheels
The wheels on the front and rear axles
are different. For this reason, pay at-
tention to the markings on the inside of
the wheel rims. Wheels marked “REAR
AXLE ONLY” on the inside of the rim
may only be fitted on the rear axle.
When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Tire care and maintenanceRegularly check your tire inflation pressure
at least once a month. For more informa-
tion on checking tire inflation pressure see
“Recommended tire inflation pressure”
(
page 311).
Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:
excessive treadwear (
page 303)
cord or fabric showing through the
tire’s rubber
bumps, bulges, cuts, cracks or splits in
the tread or side of the tire
Replace the tire if you find any of the above
conditions.
Make sure you also inspect the spare tire
periodically for condition and inflation.
Spare tires will age and become worn over
time even if never used, and thus should be
inspected and replaced when necessary.Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:
Driving style
Tire inflation pressure
Distance driven
Warning!
G
Regularly check the tires for damage. Dam-
aged tires can cause tire inflation pressure
loss. As a result, you could lose control of
your vehicle.
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
Warning!
G
Tires and spare tire should be replaced after
6 years, regardless of the remaining tread.
Page 304 of 498

303 Operation
Tires and wheels
Tread depth
Do not allow your tires to wear down too
far. Adhesion properties on wet roads are
sharply reduced at tread depths under 1⁄8in (3 mm).
Tread wear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and
become visible at a tread depth of approx-
imately
1/16
in (1.6 mm), at which point
the tire is considered worn and should be
replaced.
Recommended minimum tire tread depth:
Summer tires
1/8in (3 mm)
Winter tires
1/6in (4 mm)
1TWI (T
read W
ear I
ndicator)
The treadwear indicator appears as a solid
band across the tread.Storing tires
Cleaning tires
Warning!
G
Although the applicable federal motor safety
laws consider a tire to be worn when the
treadwear indicators (TWI) become visible at
approximately
1/16in (1.6 mm), we recom-
mend that you do not allow your tires
to wear down to that level. As tread depth
approaches
1/8in (3 mm), the adhesion
properties on a wet road are sharply re-
duced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.!Never use a round nozzle to power
wash tires. The intense jet of water can
result in damage to the tire.
Always replace a damaged tire.