tire size MERCEDES-BENZ S-Class 2008 W221 Comand Manual

601 Operation
Tires and wheels
the service description for the tire must
be referred to. The service description
is comprised of the tire load rating5
(page 598) and the tire speed
rating6 (
page 598).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 598) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description5 and6
(
page 598) 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
Load identification
1Load identification
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.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

602 OperationTires and wheelsIn addition to tire load rating, special load
identification1 may be molded into the
tire sidewall following the letter designat-
ing the tire speed rating6 (
page 598).
No specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
XL (Extra Load): designates an extra load
(or reinforced) tire.
Light Load: designates a light load tire.
C, D, E: designates load range associated
with the maximum load a tire can carry at
a specified pressure.
DOT, Tire Identification Number (TIN)
U.S. tire regulations require each new tire
manufacturer or tire retreader to mold a
TIN into or onto a sidewall of each tire
produced.
The TIN is a unique identifier which facili-
tates efforts by tire manufactures to notify
purchasers in recall situations or other safety matters concerning tires and gives
purchasers the means to easily identify
such tires.
The TIN is comprised of “Manufacturer’s
identification mark”, “Tire size”, “Tire type
code” and “Date of manufacture”.
1DOT
2Manufacturer’s identification mark
3Tire size
4Tire type code (at the option of the tire
manufacturer)
5Date of manufactureDOT (D
epartment o
f T
ransportation)
A tire branding symbol1 (
page 602)
which denotes the tire meets require-
ments of the U.S. Department of Transpor-
tation.
Manufacturer’s identification mark
The manufacturer’s identification mark2
(
page 602) denotes the tire
manufacturer.
New tires have a mark with two symbols.
Retreaded tires have a mark with four sym-
bols. For more information on retreaded
tires (
page 582).
Tire size
The code3 (
page 602) indicates the
tire size.
Tire type code
The code4 (page 602) may, at the
option of the manufacturer, be used as a
descriptive code for identifying significant
characteristics of the tire.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

608 OperationTires and wheelsPSI (P
ounds per s
quare i
nch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
The recommended tire inflation pressure
for normal driving conditions is listed on
the Tire and Loading Information placard
located on the driver’s door B-pillar and
provides best handling, tread life and
riding comfort. If so equipped, supplemen-
tal information pertaining to special driving
situations can be found on the tire inflation
pressure label on the inside of the fuel filler
flap.
Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.TIN (T
ire I
dentification N
umber)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.
Traction
Force exerted by the vehicle on the road
via the tires. The amount of grip provided.
Tread
The portion of a tire that comes into
contact with the road.
Treadwear indicators
Narrow bands, sometimes called
“wear bars” that show across the tread of
a tire when only
1/16in (1.6 mm) of tread
remains.

609 Operation
Tires and wheels
Uniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire’s traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The
ratings are molded into the sidewall of the
tire.
Vehicle maximum load on the tire
Load on an individual tire that is
determined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing it by two.Rotating tiresTire rotation can be performed on vehicles
with tires of the same dimension all
around. If your vehicle is equipped with
tires of the same dimension all around,
tires can be rotated, observing a
front-to-rear rotation pattern that will
maintain the intended rotation (spinning)
direction of the tire (
page 585).
In some cases, such as when your vehicle
is equipped with mixed-size tires (different
tire dimension front vs. rear), tire rotation
is not possible.
If applicable to your vehicle’s tire configu-
ration, tires can be rotated according to
the tire manufacturer’s recommended in-
tervals in the tire manufacturer’s warranty
pamphlet located in your vehicle literature
portfolio. If none is available, tires should
be rotated every 3 000 to 6 000 miles
(5 000 to 10 000 km), or sooner if neces-
sary, according to the degree of tire wear.
The same rotation (spinning) direction
must be maintained (page 585). Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.
For information on wheel change, see the
“Practical hints” section (
page 723).
Warning!
G
Rotate front and rear wheels only if the tires
are of the same dimension.
If your vehicle is equipped with mixed-size
tires (different tire dimensions front vs.
rear), tire rotation is not possible.
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
110 lb-ft (150 Nm).
Only use Genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.

611 Operation
Winter driving
Snow chainsSnow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.
Please observe the following guidelines
when using snow chains:


Use of snow chains is not permissible
with all wheel/tire combinations
(page 754).


Use snow chains in pairs and on rear
wheels only. Follow the manufacturer’s
mounting instructions.


Only use snow chains that are
approved by Mercedes-Benz. Any
authorized Mercedes-Benz Center will
be glad to advise you on this subject.


Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.


Do not use snow chains on the spare
wheel (
page 754).
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Center.!
When driving with snow chains, always se-
lect the raised level of the level control system
Airmatic (
page 468) or ABC* (
page 471).
Other settings may result in damage to your
vehicle.
!
Even on vehicles with all-wheel-drive, use
snow chains on rear tires only.
Some tire sizes do not leave adequate clearance
for snow chains. To help avoid serious damage to
your vehicle or tires, make sure that the use of
snow chains is permissible as specified in the
“Technical data” section of this Operator’s
Manual, see “Rims and tires” (
page 754).
!
If snow chains are mounted to the front
wheels, they may scrape against the body or axle
components. The tires or the vehicle could be
damaged as a result.
i
All models except S 63 AMG:
When driving with snow chains, you may wish to
switch off the ESP
® (page 74) before setting
the vehicle in motion. This will improve the
vehicle’s traction.
i
S 63 AMG:
Do not switch off the ESP
® when driving in snow
or with snow chains mounted.

639 Practical hints
What to do if …?
Warning!
G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
vehicle placard or the tire inflation pressure
label. (If your vehicle has tires of a different
size than the size indicated on the vehicle
placard or the tire inflation pressure label,
you should determine the proper tire infla-
tion pressure for those tires).
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly under-inflated tire causes the tire to over-
heat and can lead to tire failure.
Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’s responsibility to maintain correct tire
pressure, even if under-inflation has not
reached the level to trigger illumination of
the TPMS low tire pressure telltale.
USA only:
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately
one minute and then remain continuously
illuminated. This sequence will continue
upon subsequent vehicle start-ups as long
as the malfunction exists. When the mal-
function indicator is illuminated, the system
may not be able to detect or signal low tire
pressure as intended.
TPMS malfunctions may occur for a variety
of reasons, including the installation of
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from
functioning properly. Always check the
TPMS malfunction telltale after replacing
one or more tires or wheels on your vehicle
to ensure that the replacement or alternate
tires and wheels allow the TPMS to continue
to function properly.

724 Practical hintsFlat tirePreparing the vehicle
Prepare the vehicle as described
(page 723).

Take vehicle tool kit tray and vehicle
jack out of trunk (
page 705).

Take the spare wheel from the wheel
well under the trunk floor
(page 707).
Lifting the vehicle

Prevent the vehicle from rolling away
by blocking wheels with wheel chocks
or other sizeable objects.
One wheel chock is included with the
vehicle tool kit (
page 707).
When changing wheel on a level surface:

Place the wheel chock in front of and
another sizeable object behind the
wheel that is diagonally opposite to the
wheel being changed.Always try lifting the vehicle using the jack
on a level surface. However, should cir-
cumstances require you to do so on a hill,
place the wheel chock and another size-
able object as follows:

Place the wheel chock and another
sizeable object on the downhill side
blocking both wheels on the side of the
vehicle not being worked on.

Wheel wrench

On wheel to be changed, loosen but
do not yet remove the wheel bolts
(approximately one full turn with
wrench 1).
Warning!
G
The jack is designed exclusively for jacking
up the vehicle at the jack take-up brackets
built into both sides of the vehicle. To help
avoid personal injury, use the jack only to lift
the vehicle during a wheel change. Never
get beneath the vehicle while it is supported
by the jack. Keep hands and feet away from
the area under the lifted vehicle. Always en-
gage the electronic parking brake and block
wheels before raising vehicle with jack.
Do not disengage electronic parking brake
while the vehicle is raised. Be certain that
the jack is always vertical (plumb line) when
in use, especially on hills. Always try to use
the jack on level surface.
Make sure the jack arm is fully seated in the
jack take-up bracket. Always lower the vehi-
cle onto sufficient capacity jackstands be-
fore working under the vehicle.

728 Practical hintsFlat tire6Wheel wrench
Tighten the five wheel bolts evenly, fol-
lowing the diagonal sequence illustrat-
ed (1 to 5), until all bolts are tight.
Observe a tightening torque of
110 lb-ft (150 Nm).

Fully collapse the jack, with handle
folded in (storage position),
(page 706).

Store the jack and the other vehicle
tools in the designated storage space
underneath the trunk floor
(page 705).
Warning!
G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
110 lb-ft (150 Nm).i
Vehicles with Advanced TPMS:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.

754 Technical dataRims and tires!
Only use tires which have been tested and
approved by Mercedes-Benz. Tires approved by
Mercedes-Benz are developed to provide best
possible performance in conjunction with the
driving safety systems on your vehicle such as
ABS or ESP
®. Tires specially developed for your
vehicle and tested and approved by
Mercedes-Benz can be identified by finding the
following on the tire’s sidewall:


MO = M
ercedes-Benz O
riginal equipment
tires
AMG vehicles:
Does not apply to all approved tires on AMG
vehicles. For information on tested and
approved tires for AMG vehicles, contact an
authorized Mercedes-Benz Center.
Using tires other than those approved by
Mercedes-Benz may result in damage that is not
covered by the Mercedes-Benz Limited
Warranty.
!
Using tires other than those approved by
Mercedes-Benz can have detrimental effects,
such as


poor handling characteristics


increased noise


increased fuel consumption
Moreover, tires and rims not approved by
Mercedes-Benz may, under load, exhibit dimen-
sional variations and different tire deformation
characteristics that could cause them to come
into contact with the vehicle body or axle parts.
Damage to the tires or the vehicle may be the
result.
i
Further information on tires and rims is
available at any authorized Mercedes-Benz
Center. A placard with the recommended tire in-
flation pressures is located on the driver’s door
B-pillar (
page 585). Some vehicles may have
supplemental tire inflation pressure information
for driving at high speeds (
page 591) or for ve-
hicle loads less than the maximum loaded
vehicle condition (
page 598). If such informa-
tion is provided, it can be found on the placard lo-
cated on the inside of the fuel filler flap. The tire inflation pressure should be checked
regularly and should only be adjusted on cold
tires. Follow tire manufacturer’s maintenance
recommendation included with vehicle.
i
The following pages also list the approved
wheel rim and tire sizes for equipping your vehi-
cles with winter tires. Winter tires are not avail-
able as standard or optional factory equipment,
but can be purchased from an authorized
Mercedes-Benz Center.
Depending on vehicle model and the standard or
optional factory-equipped wheel rim/tire config-
uration on your vehicle (Appearance Package,
Sport Package etc.), equipping your vehicle with
winter tires approved for your vehicle model may
also require the purchase of two or four wheel
rims of the recommended size for use with these
winter tires. Contact an authorized
Mercedes-Benz Center for more information.

755 Technical data
Rims and tires
Same size tiresModel
S 450 4MATIC
S 550
S 550 4MATIC
S 450 4MATIC*
S 550 4MATIC*
S600
S550 (Sport Package*)
S600 (Sport Package*)
Rims (light alloy)
8.5 J x18 H2
8.5 J x 19 H2
8.5 J x18 H2
Wheel offset
1.69 in (43 mm)
1.69 in (43 mm)
1.69 in (43 mm)
Summer tires
1
1Radial-ply tires.
–
255/40 R19 96Y
–