2012 MERCEDES-BENZ SL-CLASS ROADSTER tires

Aspect ratio
Aspect ratio ; 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
Tire code = indicates the tire construction
type. The “R” stands for radial tire type. Letter
“D” means diagonal 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” ( Y page 202).
Rim diameter
Rim diameter ? is the diameter of the bead
seat, not the diameter of the rim edge. The
rim diameter is indicated in inches (in).
Load indexGWarning!
The tire load rating must always be at least
half of the GAWR of your vehicle. Otherwise,
tire failure may be the result which may cause
an accident and/or serious injury to you or
others.
Always replace rims and tires with the same
designation, manufacturer and type as shown
on the original part.
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.
Load index A is a numerical code associated
with the maximum load a tire can support.
For example, a load rating of 91 corresponds
to a maximum load of 1356 lb (615 kg) the
tire is designed to support. See also
“Maximum tire load” (Y page 197) where the
maximum load associated with the load index
is indicated in kilograms and lbs.
For additional information on the load index,
see “Load identification” ( Y page 204).
Speed symbol GWarning!
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 serious
personal injury and possible death, for you
and for others.
Regardless of the tire speed rating, local
speed limits should be obeyed. Use prudent
driving speeds appropriate to prevailing
conditions.
Speed symbol B indicates the approved
maximum speed (tire speed rating) for the
tire.
Summer tires
IndexSpeed ratingQup 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)ZR...Yup to 186 mph (300 km/h)202Tires and wheelsOperation
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IndexSpeed ratingZR...(..Y)above 186 mph (300 km/h)ZRabove 149 mph (240 km/h)
RAt 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 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
load index A and speed symbol B.
If your tire includes “ZR” in the size
designation and no service description is
given, the tire manufacturer must be
consulted for the maximum speed
capability.
If a service description is given, the speed
capability 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
capability of the tire is limited to 186 mph
(300 km/h).
R 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 symbol in parenthesis designates
the maximum speed capability 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
IndexSpeed ratingQ M+S 15up to 100 mph (160 km/h)T M+S15up to 118 mph (190 km/h)IndexSpeed ratingH M+S 15up to 130 mph (210 km/h)V M+S15up to 149 mph (240 km/h)
i
Not all M+S rated tires provide special
winter performance. Make sure the tires
you use show M+S and the mountain/
snowflake imarking on the tire
sidewall. These tires meet specific snow
traction performance requirements of the
Rubber Manufacturers Association (RMA)
and the Rubber Association of Canada
(RAC) and have been designed specifically
for use in snow conditions.
An electronic speed limiter prevents your
vehicle from exceeding a speed of:
R 155 mph (250 km/h):
- SL 550
- SL 550 (Sport Package)
- SL 600
- SL 600 (Sport Package)
- SL 63 AMG
- SL 65 AMG
R 186 mph (300 km/h):
- SL 63 AMG (Performance Package)
- SL 65 AMG with increased top speed
The factory equipped tires on your vehicle
may have a tire speed rating above the
maximum speed permitted by the electronic
speed limiter.
Make sure your tires have the required tire
speed rating as specified for your vehicle in
the “Technical data” section ( Y page 299),
for example when purchasing new tires.
If you are uncertain about the correct reading
of the information given on a tire’s sidewall,
any authorized Mercedes-Benz Center will be
glad to assist you.
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Load identification
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
In addition to the load index, special load
identification : may be molded into the tire
sidewall following the letter designating the
speed symbol B (Y page 201).
RNo specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
RXL or Extra Load: designates an extra load
(or reinforced) tire.
RLight Load: designates a light load tire.
RC, 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. The TIN
facilitates efforts by tire manufactures to
notify purchasers in recall situations or other
safety matters concerning tires. It 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”
A.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
DOT (Department of Transportation)
Tire branding symbol : denotes that the tire
meets requirements of the U.S. Department
of Transportation.
Manufacturer’s identification mark
Manufacturer’s identification mark ;
denotes the tire manufacturer.
New tires have a mark with two symbols.
Retreaded tires have a mark with four
symbols. For more information on retreaded
tires, see (Y page 186).
Tire size
Code = indicates the tire size.
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Tire type code
Tire type code ? 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 manufacture A identifies the
week and year of manufacture.
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, “3208” represents the 32nd
week of 2008.
Tire ply material
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
This marking tells you about the type of cord
and number of plies in the sidewall : and
under the tread ;.
Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power seats,
radio, and heater, to the extent that these
items are available as factory-installed
equipment (whether installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire. Air
pressure is expressed in pounds per square
inch (psi), kilopascal (kPa), or bar.
Aspect ratio
Dimensional relationship between tire
section height and section width expressed
in percentage.
Bar
Metric unit for air pressure. There are
14.5038 pounds per square inch (psi) to
1 bar; there are 100 kilopascals (kPa) to 1 bar.
Bead
The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle has
been sitting for at least 3 hours or driven no
more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with standard
equipment including the maximum capacity
of fuel, oil, and coolant, and, if so equipped,
air conditioning and additional optional
equipment, but without passengers and
cargo.
DOT (Department of Transportation)
A tire branding symbol which denotes the tire
meets requirements of the U.S. Department
of Transportation.
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GAWR (Gross Axle Weight Rating)
The GAWR is the maximum permissible axle
weight. The gross vehicle weight on each axle
must never exceed the GAWR for the front
and rear axle indicated on the certification
label located on the driver’s door B-pillar.
GVW (Gross Vehicle Weight)
The GVW comprises the weight of the vehicle
including fuel, tools, spare wheel, installed
accessories, passengers and cargo and, if
applicable, trailer tongue load. The GVW must
never exceed the GVWR indicated on the
certification label located on the driver’s door
B-pillar.
GVWR (Gross Vehicle Weight Rating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passengers,
fuel, and cargo and, if applicable, trailer
tongue load). It is indicated on the
certification label located on the driver’s door
B-pillar.
Kilopascal (kPa)
Metric unit for air pressure. There are 6.9 kPa
to 1 psi; another metric unit for air pressure
is bar. There are 100 kilopascals (kPa) to
1 bar.
Load index
Numerical code associated with the
maximum load a tire can support.
Maximum load rating
The maximum load in kilograms and pounds
that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit, and production options
weight.
Maximum permissible tire inflation
pressure
This number is the greatest amount of air
pressure that should ever be put in the tire.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by 68 kilograms
(150 lb).
Occupant distribution
The distribution of occupants in a vehicle at
their designated seating positions.
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.
PSI (Pounds per square inch)
A standard unit of measure for air pressure.
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. It provides best
handling, tread life and riding comfort.
Supplemental 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.
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Sidewall
The portion of a tire between the tread and
the bead.
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 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”.
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
manufacturers 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 (speed symbol);
indicates the speed range for which a tire is
approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lb) times the vehicle’s
designated seating capacity.
Traction
The adhesive friction of a tire on a surface on
which it moves. 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 / 16 in (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 U.S.
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.
Winter driving
General information
Have your vehicle winterized at an authorized
Mercedes-Benz Center.
Winter tires
GWarning!
Winter tires with a tread depth of less than
1 / 6 in (4 mm) must be replaced. They are no
longer suitable for winter operation.
GWarning!
If you use your spare wheel 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 wheel replaced by a regular
road wheel with a winter tire at the nearest
authorized Mercedes-Benz Center.
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Always use winter tires at temperatures
below 45‡ (7†) 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 imarking on the tire sidewall.
These tires meet specific snow traction
performance requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC) and
have been designed specifically for use in
snow conditions. Use of winter tires is the
only way to achieve the maximum
effectiveness of your vehicle’s driving safety
systems such as the ABS and the ESP ®
in
winter operation.
For safe handling, make sure all mounted
winter tires are of the same make and have
the same tread design.
For information on winter tires for your
vehicle model, see the “Technical data”
section ( Y page 299).
Always observe the speed rating of the winter
tires installed on your vehicle.
After installing winter tires:XCheck the tire inflation pressure and adjust
it if necessary ( Y page 189).XRestart the Advanced Tire Pressure
Monitoring System ( Y page 190).
Snow chains
! When driving with snow chains, always
select setting 1 of the vehicle level control.
Other settings may result in damage to your
vehicle.
! Some tire sizes do not leave adequate
clearance for snow chains. To help avoid
serious damage to your vehicle or tires,
make sure the use of snow chains is
permissible as specified in the “Technical
data” section of this Operator’s Manual.
Snow 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.
Observe the following guidelines when using
snow chains:
R Use of snow chains is not permissible with
all wheel/tire combinations ( Y page 299).
R Use snow chains in pairs and on rear
wheels only. Follow the manufacturer’s
mounting instructions.
! 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.
R Only use snow chains that are approved by
Mercedes-Benz. Any authorized Mercedes-
Benz Center will be glad to advise you on
this subject.
R Use of snow chains may be prohibited
depending on location. Always check local
and state laws before installing snow
chains.
R Do not use snow chains on the spare wheel.
i When driving with snow chains, you may
wish to switch off the ESP ®
(Y page 56)
before setting the vehicle in motion. This
will improve the vehicle’s traction.
Winter driving instructions
GWarning!
If the vehicle becomes stuck in snow, make
sure snow is kept clear of the exhaust pipe
and from around the vehicle with the engine
running. Otherwise, deadly carbon monoxide
(CO) gases may enter vehicle interior
resulting in unconsciousness and death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
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GWarning!
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWarning!
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle’s ABS will not prevent
this type of loss of control.
The most important rule for slippery or icy
roads is to drive sensibly and to avoid abrupt
acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding, shift
the automatic transmission to neutral
position N. Try to keep the vehicle under
control by corrective steering action.
i For information on driving with snow
chains, see “Snow chains” ( Y page 208).
Road salts and chemicals can adversely
affect braking efficiency. Increased pedal
force may become necessary to produce the
normal brake effect.
Depressing the brake pedal periodically when
traveling at length on salt-strewn roads can
bring road-salt-impaired braking efficiency
back to normal.
If the vehicle is parked after being driven on
salt-treated roads, the braking efficiency
should be tested as soon as possible after
driving is resumed.
GWarning!
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Driving instructions
Drive sensibly – save fuel
To save fuel you should:
R Keep tires at the recommended inflation
pressures.
R Remove unnecessary loads.
R Allow engine to warm up under low load
use.
R Avoid frequent acceleration and
deceleration.
R Have all maintenance work performed at
the intervals specified in the Maintenance
Booklet and as required by the
Maintenance system. Contact an
authorized Mercedes-Benz Center.
Fuel consumption is also increased by driving
in cold weather, in stop-and-go traffic, on
short trips and in mountainous areas.
Drinking and driving
GWarning!
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident are greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Pedals
GWarning!
Make sure absolutely no objects are
obstructing the pedals’ range of movement.
Keep the driver’s footwell clear of all
obstacles. If there are any floormats or
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