2008 MERCEDES-BENZ CL550 service

561 Operation
Tires and wheels
Tires and wheels
Contact an authorized Mercedes-Benz
Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice 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
required.


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).


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. Contact an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension
components can be damaged.


The operating clearance of the wheels
and the tires may no longer be correct.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is worn to minimum tread depth,
or if the tires have sustained damage, re-
place them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result 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.

562 OperationTires and wheelsTire care and maintenance
Regularly check the tire inflation pressure
at least once a month. For more informa-
tion on checking tire inflation pressure,
see “Recommended tire inflation pres-
sure” (
page 569).Tire inspection
Every time you check the tire inflation
pressure, you should also inspect your
tires for the following:


excessive treadwear (
page 563)


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 degrade over time
even if never used, and thus should be in-
spected 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.

573 Operation
Tires and wheels

Switch on the ignition (
page 365).

Press( or& to select the menu
“Service”.

Press$ or% to select “Tire
Pressure”.

Press#.
i
When the message “Tire Pressures Dis-
played After Driving a Few Minutes” appears in
the display, the individual inflation pressure val-
ues are matched with the tires. The individual
values are displayed after a few minutes driving.Warning!
G
It is the driver’s responsibility to calibrate
the Advanced TPMS on the recommended
cold inflation pressure. Underinflated tires
affect the ability to steer or brake the vehi-
cle. You might lose control over the vehicle.
i
With a spare wheel without wheel sensor
mounted, the system may still indicate the tire
inflation pressure of the removed wheel for some
minutes. If this happens, keep in mind that the
indicated value where the spare wheel is mount-
ed does not reflect the actual spare tire inflation
pressure.
Warning!
G
The Advanced TPMS does not indicate a
warning for wrongly selected inflation pres-
sures. Always adjust tire inflation pressure
according to the Tire and Loading Informa-
tion placard on the driver’s door B-pillar or,
if available, the supplemental tire inflation
pressure information on the inside of the
fuel filler flap.
The Advanced TPMS is not able to issue a
warning due to a sudden dramatic loss of
pressure (e.g. tire blowout caused by a for-
eign object). In this case bring the vehicle to
a halt by carefully applying the brakes and
avoiding abrupt steering maneuvers.

575 Operation
Tires and wheels
Reactivating Advanced TPMS
The Advanced TPMS must be reactivated
when you have adjusted the tire inflation
pressure to a new level (e.g. because of dif-
ferent load or driving conditions). The Ad-
vanced TPMS is then recalibrated to the
current tire inflation pressures.
Using the Tire and Loading Information
placard on the driver’s door B-pillar
(page 564) or, if available, the sup-
plemental tire inflation pressure
information on the inside of the fuel fill-
er flap (
page 550), make sure the tire
inflation pressure of all four tires is
correct.

Switch on the ignition (
page 365).

Press( or& to select the menu
“Service”.

Press$ or% to select
“Tire Pressure”.

Press#.
You will see

the current inflation pressures for
each tire
or


the message
“Tire Pressures
Displayed After Driving
a Few Minutes”
appear in the multifunction display.

Press%.
The message
“Use Current
Pressures As New
Reference Values
Press "OK" to Confirm
Tire Press.”
appears in the multifunction display.
Warning!
G
It is the driver’s responsibility to calibrate
the Advanced TPMS on the recommended
cold inflation pressure. Underinflated tires
affect the ability to steer or brake the vehi-
cle. You might lose control over the vehicle.
i
Reactivate the Advanced TPMS after adjust-
ing the tire inflation pressure to the inflation
pressure recommended for the vehicle operating
condition. Tire inflation pressure should only be
adjusted on cold tires. Observe the recommend-
ed tire inflation pressure on the Tire and Loading
Information placard on the driver’s door B-pillar
(
page 564). Some vehicles may have supple-
mental tire inflation pressure information for
driving at high speeds (
page 570) or for vehi-
cle loads less than the maximum loaded vehicle
condition. If such information is provided, it can
be found on the inside of the fuel filler flap
(
page 550).
i
After wheel rotation or sensor replacement,
the vehicle must be parked for 20 minutes be-
fore attempting to reactivate the Advanced
TPMS.
i
The menu overview can be found on
(
page 284).


579 Operation
Tires and wheels
For additional information on tire load
rating, see “Load identification”
(page 581).
Tire speed rating
The tire speed rating6 (
page 577)
indicates the approved maximum speed
for the tire.Summer tires
Warning!
G
The tire load rating must always be at least
half of the GAWR (
page 586) of your
vehicle. Otherwise, tire failure may be the
result which may cause an accident and/or
serious personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!
G
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard located on
the driver’s door B-pillar. Overloading the
tires can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.
i
Tire load rating5 (
page 577) and tire
speed rating6 (
page 577) are also referred
to as “service description”.
Warning!
G
Even when permitted by law, never operate
a vehicle at speeds greater than the
maximum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire
failure, causing loss of vehicle control and
possibly resulting in an accident and/or
personal injury and possible death, for you
and for others.
i
Tire load rating5 (
page 577) and tire
speed rating6 (
page 577) are also referred
to as “service description”.
Index
Speed rating
Q
up to 100 mph (160 km/h)
R
up to 106 mph (170 km/h)
S
up to 112 mph (180 km/h)
T
up to 118 mph (190 km/h)
H
up to 130 mph (210 km/h)
V
up to 149 mph (240 km/h)
W
up to 168 mph (270 km/h)
Y
up to 186 mph (300 km/h)
(Y)
above 186 mph (300 km/h)
ZR
above 149 mph (240 km/h)

580 OperationTires and wheels

At the tire manufacturer’s option, any
tire with a speed capability above
149 mph (240 km/h) can include a
“ZR” in the size designation (for exam-
ple: 245/40 ZR18). To determine the
maximum speed capability of the tire,
the service description for the tire must
be referred to. The service description
is comprised of the tire load rating5
(page 577) and the tire speed
rating6 (
page 577).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 577) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description5 and6
(
page 577) is given, the speed capa-
bility is limited by the speed symbol in
the service description.
Example: 245/40 ZR18 97Y.
In this example, “97Y” is the service
description. The letter “Y” designates the speed rating and the speed capabil-
ity of the tire is limited to 186 mph
(300 km/h).


Any tire with a speed capability above
186 mph (300 km/h) must include a
“ZR” in the size designation AND the
service description must be placed in
parenthesis.
Example: 275/40 ZR 18 (99Y).
The “(Y)” speed rating in parenthesis
designates the maximum speed capa-
bility of the tire as being above
186 mph (300 km/h). Consult the tire
manufacturer for the actual maximum
permissible speed of the tire.All-season and winter tires
Index
Speed rating
QM+S
1
1or M+S.for winter tires
up to 100 mph (160 km/h)
TM+S
1
up to 118 mph (190 km/h)
HM+S
1
up to 130 mph (210 km/h)
VM+S
1
up to 149 mph (240 km/h)
i
Not all M+S rated tires provide special win-
ter performance. Make sure the tires you use
show M+S and the mountain/snow-
flake.
marking on the tire sidewall. These
tires meet specific snow traction performance
requirements of the Rubber Manufacturers As-
sociation (RMA) and the Rubber Association of
Canada (RAC) and have been designed specifi-
cally for use in snow conditions.

584 OperationTires and wheelsQuality grades can be found, where appli-
cable, on the tire sidewall between tread
shoulder and maximum section width. For
example:
All passenger car tires must conform to
federal safety requirements in addition to
these grades.
Treadwear
The treadwear grade is a comparative rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course. For ex-
ample, a tire graded 150 would wear one
and one-half (1
1/2) times as well on the
government course as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from the norm due to variations in driving
habits, service practices and differences in
road characteristics and climate.
Traction
The traction grades, from highest to low-
est, are AA, A, B, and C. Those grades rep-
resent the tire’s ability to stop on wet
pavement as measured under controlled
conditions on specified government test
surfaces of asphalt and concrete. A tire
marked C may have poor traction perfor-
mance.Temperature
The temperature grades are A (the high-
est), B, and C, representing the tire’s resis-
tance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor
laboratory test wheel. Sustained high tem-
perature can cause the material of the tire
to degenerate and reduce tire life, and ex-
cessive temperature can lead to sudden
tire failure. The grade C corresponds to the
minimum level of performance which all
passenger car tires must meet under the
Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher
levels of performance on the laboratory
test wheel than the minimum required by
law.
Treadwear
Traction
Temperature
200
AA
A
Warning!
G
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.

590 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 Windshield
Washer Concentrate “MB Summerfit”
to a premixed windshield washer sol-
vent/antifreeze which is formulated for
below freezing temperatures
(page 739).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure that the engine can be started,
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 Can-
ada (RAC) and have been designed specif-
ically for use in snow conditions. Use of
winter tires is the only way to achieve the
maximum effectiveness of the ABS, EBP
and ESP
® 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
vehicle, you must place a notice to this
effect where it will be seen by the driver.
Such notices are available from your tire
dealer or from 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.