2012 MERCEDES-BENZ SL-CLASS ROADSTER tires

pressures for the original equipment tires
on your vehicle.
(2)The certification label, also found on the
driver’s door B-pillar. It tells you about the
gross weight capacity of your vehicle,
called the Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight
of the vehicle, all occupants, fuel and
cargo. The certification label also tells
you about the front and rear axle weight
capacity, called the Gross Axle Weight
Rating (GAWR).
The GAWR is the total allowable weight
that can be carried by a single axle (front
or rear). Never exceed the GVWR or
GAWR for either the front axle or rear
axle.
:Driver’s door B-pillar
Following is a discussion on how to work with
the information contained on the Tire and
Loading Information placard with regards to
loading your vehicle.
Tire and Loading Information
GWarning!
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard 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.
Tire and Loading Information placard
iData shown on Tire and Loading
Information placard example are for
illustration purposes only. Load limit data
are specific to each vehicle and may vary
from data shown in the following
illustration. Refer to Tire and Loading
Information placard on vehicle for actual
data specific to your vehicle.
The Tire and Loading Information placard
showing load limit information : is located
on the driver’s door B-pillar (Y page 194).
XLocate the statement “The combined
weight of occupants and cargo should
never exceed XXX kilograms or XXX lbs.”
on the Tire and Loading Information
placard.
The combined weight of all occupants,
cargo/luggage and trailer tongue load (if
applicable) should never exceed the weight
referenced in that statement.
Seating capacity
iData shown on Tire and Loading
Information placard example are for
illustration purposes only. Seating capacity
data are specific to each vehicle and may
vary from data shown in the following
illustration. Refer to Tire and Loading
Information placard on vehicle for actual
data specific to your vehicle.
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The seating capacity gives you important
information on the number of occupants that
can be in the vehicle. The Tire and Loading
Information placard showing seating
capacity : is located on the driver’s door
B-pillar (Y page 194).
Steps for determining correct load limit
The following steps have been developed as
required of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part 575
pursuant to the “National Traffic and Motor
Vehicle Safety Act of 1966”.
XStep 1: Locate the statement “The
combined weight of occupants and cargo
should never exceed XXX kg or XXX lbs.”
on your vehicle’s Tire and Loading
Information placard.
XStep 2: Determine the combined weight of
the driver and passengers that will be riding
in your vehicle.
XStep 3: Subtract the combined weight of
the driver and passengers from
XXX kilograms or XXX lbs.
XStep 4: The resulting figure equals the
available amount of cargo and luggage load
capacity. For example, if the “XXX” amount
equals 1 400 lbs and there will be five
150 lbs passengers in your vehicle, the
amount of available cargo and luggage load
capacity is 650 lbs
(1 400 - 750 (5 x 150) = 650 lbs).
XStep 5: Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely exceed
the available cargo and luggage load
capacity calculated in step 4.
XStep 6 (if applicable): If your vehicle will
be towing a trailer, load from your trailer
will be transferred to your vehicle. Consult
this manual to determine how this reduces
the available cargo and luggage load
capacity of your vehicle (Y page 196).
The following table shows examples on how
to calculate total and cargo load capacities
with varying seating configurations and
number and size of occupants. The following
examples use a load limit of 1 500 lbs. This
is for illustration purposes only. Make sure
you are using the actual load limit for your
vehicle stated on the vehicle’s Tire and
Loading Information placard (Y page 194).
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Example 1Example 2Step 1Combined weight limit of
occupants and cargo from
Tire and Loading Information
placard1 500 lbs1 500 lbsStep 2Number of occupants (driver
and passengers)12Occupants weightOccupant 1: 175 lbsOccupant 1: 175 lbs
Occupant 2: 195 lbsCombined weight of all
occupants175 lbs370 lbsStep 3Available cargo/luggage and
trailer tongue weight (total
load limit from Tire and
Loading Information placard
minus combined weight of all
occupants)1 500 lbs - 175 lbs =
1 325 lbs1 500 lbs - 370 lbs =
1 130 lbsThe higher the weight of all occupants, the
less cargo and luggage load capacity is
available.
For more information, see “Trailer tongue
load” ( Y page 196).
Certification label
Even after careful determination of the
combined weight of all occupants, cargo and
the trailer tongue load (if applicable)
( Y page 196) as to not exceed the
permissible load limit, you must make sure
your vehicle never exceeds the Gross Vehicle
Weight Rating (GVWR) and the Gross Axle
Weight Rating (GAWR) for either the front or
rear axle. You can obtain the GVWR and
GAWR from the certification label. The
certification label can be found on the driver’s
door B-pillar , see the “Technical data” section
( Y page 294).
Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants, all
cargo, and the trailer tongue load (if
applicable) must never exceed the GVWR.
Gross Axle Weight Rating (GAWR): The total
allowable weight that can be carried by a
single axle (front or rear).
To assure that your vehicle does not exceed
the maximum permissible weight limits
(GVWR and GAWR for front and rear axle),
have the loaded vehicle (including driver,
passengers and all cargo and, if applicable,
trailer fully loaded) weighed on a suitable
commercial scale.
Trailer tongue load
The tongue load of any trailer is an important
weight to measure because it affects the load
you can carry in your vehicle. If a trailer is
towed, the tongue load must be added to the
weight of all occupants riding and any cargo
you are carrying in the vehicle. The tongue
load typically is 10% of the trailer weight and
everything loaded in it.
Your Mercedes-Benz has been designed
primarily to carry passengers and their cargo.
Mercedes-Benz does not recommend trailer
towing with your vehicle.
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Maximum tire loadGWarning!
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard 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.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
The maximum tire load rating : is the
maximum weight the tires are designed to
support.
For more information on tire load rating, see
(Y page 202).
For information on calculating total and cargo
load capacities, see (Y page 195).
Direction of rotation
Unidirectional tires offer added advantages,
such as better hydroplaning performance. 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 of the tire.
Spare wheels may be mounted against the
direction of rotation (spinning) even with a
unidirectional tire for temporary use only until
the regular drive wheel has been repaired or
replaced. Always observe and follow
applicable temporary use restrictions and
speed limitations indicated on the spare
wheel.
MOExtended system
The MOExtended system allows you to
continue driving your vehicle even if there is
a total loss of pressure in one or more tires.
You may only use the MOExtended system in
conjunction with the Advanced TPMS
(Y page 190).
For information on driving in case of pressure
loss in one or more tires (emergency mode),
see the “Practical hints” section
(Y page 283).
Tire care and maintenance
GWarning!
Regularly check the tires for damage.
Damaged 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 worn to minimum tread depth, or if
the tires have sustained damage, replace
them.
Check the tire inflation pressure at least once
a month. For more information on checking
tire inflation pressure, see “Recommended
tire inflation pressure” (Y page 187).
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Tire inspection
Every time you check the tire inflation
pressure, you should also inspect your tires
for the following:
Rexcessive treadwear (Y page 198)
Rcord or fabric showing through the tire’s
rubber
Rbumps, 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
GWarning!
Tires and spare tire should be replaced after
6 years, regardless of the remaining tread.
The service life of a tire is dependent upon
varying factors including but not limited to:
RDriving style
RTire inflation pressure
RDistance driven
Tread depth
GWarning!
Although the applicable federal motor vehicle
safety laws consider a tire to be worn when
the treadwear indicators (TWI) become visible
at approximately 1/16 in (1.6 mm), we
recommend that you do not allow your tires
to wear down to that level. As tread depth
approaches 1/8 in (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.
Do not allow your tires to wear down too far.
Adhesion properties on wet roads are sharply
reduced at tread depths of less than 1/8 in
(3 mm).
Treadwear 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 approximately1/16 in (1.6 mm), at which point the tire is
considered worn and should be replaced.
The recommended minimum tire tread depth
for summer tires is 1/8 in (3 mm). The
recommended minimum tire tread depth for
winter tires is 1/6 in (4 mm).
Treadwear indicator : appears as a solid
band across the tread.
Storing tires
! Keep unmounted tires in a cool, dry place
with as little exposure to light as possible.
Protect tires from contact with oil, grease
and fuels.
Cleaning tires
! 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.
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Uniform Tire Quality Grading
Standards
The Uniform Tire Quality Grading is a U.S.
Government requirement designed to give
drivers consistent and reliable information
regarding tire performance. Tire
manufacturers are required to grade tires
based on three performance factors:
treadwear :, traction ;, and temperature
resistance =. Although not a Government of
Canada requirement, all tires made for sale in
North America have these grades branded on
the sidewall.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
Quality grades can be found, where
applicable, on the tire sidewall between tread
shoulder and maximum section width. For
example:
TreadwearTractionTemperature200AAA
All passenger car tires must conform to
federal safety requirements in addition to
these grades.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. Government test course. For example, 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
GWarning!
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.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
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 performance.
GWarning!
If ice has formed on the road, tire traction will
be substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperature is close to the freezing point.
Mercedes-Benz recommends winter tires
(Y page 207) with a minimum tread depth of
approximately 1/6 in (4 mm) on all four wheels
for the winter season to ensure normal
balanced handling characteristics. On
packed snow, they can reduce your stopping
distance compared to summer tires.
Stopping distance, however, is still
considerably greater than when the road is
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not covered with snow or ice. Exercise
appropriate caution.
! Avoid spinning of a drive wheel. This may
cause serious damage to the drivetrain
which is not covered by the Mercedes-Benz
Limited Warranty.
Temperature GWarning!
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C, representing the tire’s resistance 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 temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive
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 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.
Rotating tires
GWarning!
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.
GWarning!
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
96 lb-ft (130 Nm).
Only use genuine Mercedes-Benz wheel bolts
specified for your vehicle’s rims.
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
( Y page 197).
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
configuration, tires can be rotated according
to the tire manufacturer’s recommended
intervals 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 necessary, according
to the degree of tire wear. The same rotation
(spinning) direction must be maintained.
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 “Flat
tire” ( Y page 276).
Tire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
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Following are some explanations for the
markings on your vehicle’s tires::Uniform Tire Quality Grading Standards
(Y page 199)
;DOT, Tire Identification Number
(Y page 204)
=Maximum tire load (Y page 197)?Maximum tire inflation pressure
(Y page 193)
AManufacturerBTire ply material (Y page 205)CTire size designation, load and speed
rating (Y page 201)
DLoad identification (Y page 204)ETire name
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
For more information, see “Rims and tires”
(Y page 299).
Tire size designation, load and speed
rating:Tire width;Aspect ratio in %=Radial tire code?Rim diameterALoad index BSpeed symbol
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
General: 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
Tire width : indicates the nominal tire width
in millimeters.
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