2008 MERCEDES-BENZ S550 4MATIC warning

570 Operation
Tires and wheels
For additional information on tire load
rating, see “Load identification”
(
page 571).
Tire speed rating
The tire speed rating6 (
page 568)
indicates the approved maximum speed
for the tire.Summer tires

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 568) and the tire speed
rating6 (
page 568).
If your tire includes “ZR” in the size
designation and no service
description5 and6 (
page 568) is
given, the tire manufacturer must be
consulted for the maximum speed ca-
pability.
If a service description5 and6
(
page 568) 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).
iTire load rating5 (page 568) and tire
speed rating6 (
page 568) 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.
iTire load rating5 (page 568) and tire
speed rating6 (
page 568) are also referred
to as “service description”.
IndexSpeed rating
Qup to 100 mph (160 km/h)
Rup to 106 mph (170 km/h)
Sup to 112 mph (180 km/h)
Tup to 118 mph (190 km/h)
Hup to 130 mph (210 km/h)
Vup to 149 mph (240 km/h)
Wup to 168 mph (270 km/h)
Yup to 186 mph (300 km/h)
(Y)above 186 mph (300 km/h)
ZRabove 149 mph (240 km/h)

573 Operation
Tires and wheels
The first two figures identify the week,
starting with “01” to represent the first full
week of the calendar year. The second two
figures represent the year.
For example, “3202” represents the 32nd
week of 2002.
Maximum tire load
1Maximum tire load rating
The maximum tire load is the maximum
weight the tires are designed to support.For more information on tire load rating
(
page 569).
For information on calculating total and
cargo load capacities (
page 555).
Maximum tire inflation pressure
1Maximum permissible tire inflation
pressure
This is the maximum permissible tire
inflation pressure for the tire.
Always follow the recommended tire
inflation pressure (
page 558) for proper
tire inflation. iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
Warning!G
Do not overload the tires by exceeding the
specified load limit or total load limit as indi-
cated on the Tire and Loading Information
placard located on the driver’s door B-pillar
(
page 553). Overloading the tires can
overheat them, possibly causing a blowout.
Overloading the tires can also result in han-
dling or steering problems, or brake failure.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

574 Operation
Tires and wheels
Uniform Tire Quality Grading Standards
(U.S. vehicles)
Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.1Treadwear
2Traction
3Temperature resistance
Quality 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
Warning!G
Never exceed the max. tire inflation
pressure. Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adverse-
ly affect handling and fuel economy, and are
more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
TreadwearTractionTemperature
200AAA

575 Operation
Tires and wheels
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.Tire ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.
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.Warning!G
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underin-
flation, or excessive loading, either sepa-
rately or in combination, can cause
excessive heat build-up and possible tire
failure.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

578 Operation
Tires and wheels
TIN (Tire Identification Number)
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.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 tires
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.

579 Operation
Tires and wheels
Tire 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 553).
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 553). 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 686).
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.

580 Operation
Winter driving
Before 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 731).

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,
ESP
® and 4MATIC 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.

581 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 718).

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 718).
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 440) or ABC* (page 443).
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 718).
! 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.
iAll models except S 63 AMG:
When driving with snow chains, you may wish to
switch off the ESP
® (page 73) before setting
the vehicle in motion. This will improve the
vehicle’s traction.
iS 63 AMG:
Do not switch off the ESP® when driving in snow
or with snow chains mounted.