Page 289 of 481

288 Operation
Engine compartment
Checking engine oil level
When checking the oil level
the vehicle must be parked on level
ground
with the engine at operating tempera-
ture, the vehicle must have been sta-
tionary for at least 5 minutes with the
engine turned off
with the engine not at operating tem-
perature yet, the vehicle must have
been stationary for at least 5 minutes
with the engine turned off1Oil dipstick
2Upper (max) mark
3Lower (min) mark
To check the engine oil level with the oil
dipstick, do the following:
Open the hood (page 286).
Pull out oil dipstick1.
Wipe oil dipstick1 clean.
Fully insert oil dipstick1 into the
dipstick guide tube.
Pull out oil dipstick1 again after
approximately 3 seconds to obtain ac-
curate reading.
The oil level is correct when it is be-
tween lower (min) mark3 and
upper (max) mark2 of oil dipstick1.
If necessary, add engine oil.
For adding engine oil, see “Adding engine
oil” (
page 289).
For more information on engine oil, see
“Fuels, coolants, lubricants etc.”
(
page 448).
iCLS 550 only:
The filling quantity between the upper and lower
marks on the oil dipstick is approximately
2.1 US qt. (2.0 l).
iCLS 63 AMG only:
The filling quantity between the upper and lower
marks on the oil dipstick is approximately
1.6 US qt. (1.5 l).
Page 290 of 481

289 Operation
Engine compartment
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 379).
Adding engine oil
CLS 550
CLS 63 AMG
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 448) and
(
page 450).
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.
!Only use approved engine oils and oil filters
required for vehicles with Maintenance System.
For a listing of approved engine oils and oil fil-
ters, refer to the Factory Approved Service Prod-
ucts pamphlet (USA only) in your vehicle
literature portfolio, or contact an authorized
Mercedes-Benz Center.
Using engine oils and oil filters of specification
other than those expressly required for the Main-
tenance System, or changing of oil and oil filter
at change intervals longer than those called for
by the Maintenance System will result in engine
or emission control system damage not covered
by the Mercedes-Benz Limited Warranty.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and emis-
sion control system not covered by the
Mercedes-Benz Limited Warranty.
Page 291 of 481

290 Operation
Engine compartment
Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking the coolant level,
the vehicle must be parked on level
ground
the coolant temperature must be
below 158°F (70°C)
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.
1Marking bar in the expansion tank
2Cap
3Coolant expansion tank
Using a rag, turn cap2 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning cap2 counterclock-
wise and remove it.
The coolant level is correct if the level:
for cold coolant: reaches marking
bar1 in expansion tank3
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap2.
For more information on coolant, see the
“Technical data” section (
page 452).
Warning!G
In order to avoid potentially 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 292 of 481

291 Operation
Engine compartment
Battery
Your vehicle’s battery is located in the
trunk on the right hand side (
page 420).
The battery 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.
Warning!G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.
Page 293 of 481

292 Operation
Engine compartment
Washer system and headlamp cleaning
system*
The washer reservoir is located in the en-
gine compartment.
1Cap for washer reservoir
Fluid for the washer system and the head-
lamp cleaning system is supplied from the
washer reservoir. It has a capacity of ap-
proximately 6.9 US qt (6.5 l).During all seasons, add MB Windshield
Washer Concentrate “MB SummerFit” to
water. Premix the washer fluid in a suitable
container.
Use the tab to pull cap1 upwards.
Refill the reservoir with MB Windshield
Washer Concentrate “MB SummerFit”
and water (or commercially available
premixed washer solvent/antifreeze,
depending on ambient temperatures).For more information, see “Windshield and
headlamp washer fluid mixing ratio”
(
page 455).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.
!Always use washer solvent/antifreeze
where temperatures may fall below freezing
point. Failure to do so could result in damage to
the washer system/reservoir.
!Only use washer fluid which is suitable for
plastic lenses. Improper washer fluid can dam-
age the plastic lenses of the headlamps.
Page 294 of 481

293 Operation
Tires and wheels
Tires and wheels
Contact an authorized Mercedes-Benz
Center for information on tested and rec-
ommended rims and tires for summer and
winter operation. They can also offer ad-
vice concerning 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 of less than
1/8in (3 mm).
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).
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. The operating safety of the vehicle
cannot be assured when such tires are used.
Page 295 of 481

294 Operation
Tires and wheels
Tire care and maintenance
Regularly 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 301).
Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:
excessive treadwear (page 294)
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 drivenTread depth
Do not allow your tires to wear down too
far. Adhesion properties on wet roads are
sharply reduced at tread depths of less
than
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
1/16in (1.6 mm), at which point the
tire is considered worn and should be re-
placed.
Recommended minimum tire tread depth:
Summer tires 1/8in (3 mm)
Winter tires 1/6in (4 mm)
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.
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
Page 296 of 481

295 Operation
Tires and wheels
1TWI (Tread Wear Indicator)
The treadwear indicator appears as a solid
band across the tread.Storing tires
Cleaning tires
Direction of rotation
Unidirectional tires offer added advan-
tages, such as better hydroplaning perfor-
mance. To benefit, however, you must
make sure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the
intended direction of rotation (spinning) of
the tire.to wear down to that level. As tread depth
approaches 1/8in (3 mm), the adhesion
properties on a wet road are sharply
reduced.
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. Pro-
tect tires from contact with oil, grease and gaso-
line.
!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.
iSpare wheels may be mounted against the
direction of rotation (spinning) even with a unidi-
rectional tire for temporary use only until the reg-
ular drive wheel has been repaired or replaced.
Always observe and follow applicable temporary
use restrictions and speed limitations indicated
on the spare wheel.