311 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.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
See an authorized Mercedes-Benz Center
for information on tested and recommend-
ed rims and tires for summer and winter
operation.
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).
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.
328 OperationTires and wheelsGeneral:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only. Tire width
The tire width1 (
page 327) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (page 327) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 327) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal or bias ply construction; letter “B”
means belted-bias ply construction.
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 example: 245/40 ZR 18).
For additional information, see “Tire speed
rating” (
page 329).Rim diameter
The rim diameter4 (
page 327) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (page 327) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 333) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.
329 Operation
Tires and wheels
For additional information on tire load
rating, see “Load identification”
(page 331).Tire speed rating
The tire speed rating6 (
page 327)
indicates the approved maximum speed
for the tire.
Warning
G
The tire load rating must always be at least
half of the GAWR (
page 337) of your vehi-
cle. Otherwise, tire failure may be the result
which may cause an accident and/or seri-
ous 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 or vehicle capacity
weight as indicated on the 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.
iTire load rating5 (
page 327) and
Tire speed rating6 (page 327) are
also referred to as “service descrip-
tion”.
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 327) and
Tire speed rating6 (page 327) are
also referred to as “service descrip-
tion”.
332 OperationTires and wheelsDOT, 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 332)
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 332) 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, see (
page 311).
Tire size
The code3 (page 332) indicates the
tire size.
iFor illustration purposes only. Actual
data on tires is specific to each vehicle
and may vary from data shown in above
illustration.
333 Operation
Tires and wheels
Tire type code
The code4 (
page 332) may, at the
option of the manufacturer, be used as a
descriptive code for identifying significant
characteristics of the tire.
Date of manufacture
The date of manufacture5 (
page 332)
identifies the week and year of manufac-
ture.
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 328)
For information on calculating total and
cargo load capacities (
page 317).
iFor illustration purposes only. Actual
data on tires is 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 vehicle capacity
weight as indicated on the 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.
336 OperationTires and wheelsTemperature
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 a
level of performance which all passenger
car tires must meet under the Federal Mo-
tor 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 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 is specific to each vehicle
and may vary from data shown in above
illustration.
339 Operation
Tires and wheels
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.
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
1/6in (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 capacity weight
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle's
designated seating capacity.
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.
406 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
@
Vehicle rising
Your vehicle is adjusting to your level se-
lection.
Leveling cancelled
The “Raised” level setting is canceled at
vehicle speeds of over 75 mph
(120 km / h).
Reactivate the “Raised” level setting.
Stop, car too low
The vehicle level control is malfunction-
ing.
Avoid excessive steering input. The fend-
er or tires could otherwise be damaged.
Listen for scraping noises. Do not drive
faster than 50 mph (80 km / h).
Drive to the side of the road and se-
lect a higher vehicle level. Depending
on the type of malfunction, this may
raise the vehicle’s level.
There is otherwise danger of an accident.
Visit workshop
The system is functional only to a limited
extent.
The system display or the system is mal-
functioning.
Do not drive faster than 50 mph
(80 km / h).
Have the vehicle checked at an autho-
rized Mercedes-Benz Center.