tire type MERCEDES-BENZ SLR 2009 R199 Owner's Manual

90 Safety and SecurityPerformance enhancement systemAirbrake
The Airbrake enhances the vehicle’s driv-
ing stability. It adapts the aerodynamics of
the vehicle to the driving conditions ac-
cording to the speed and the mode set.
This is achieved using a moveable spoiler.
The Airbrake is located at the rear edge of
the trunk lid.Warning!
G
When operating the Airbrake, make sure
there is no danger of anyone being harmed
by the Airbrake operation (i.e. raising and
lowering of flap). Be especially careful when
small children are around.
Warning!
G
The following factors increase the risk of
accidents:

Excessive speed, especially in turns


Wet and slippery road surfaces


Following another vehicle too closely
The Airbrake cannot reduce this risk.
Always adjust your driving style to the pre-
vailing road and weather conditions.
i
In winter operation, the maximum effective-
ness of the Airbrake is only achieved with winter
tires (M + S tires) or snow chains as required.

242 OperationDriving instructionsMercedes-Benz recommends winter tires
(page 292) with a minimum tread depth
of approximately
1/6in (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
not covered with snow or ice. Exercise
appropriate caution.
Tire speed rating
Regardless of the tire speed rating, local
speed limits should be obeyed. Use
prudent driving speeds appropriate to
prevailing conditions.Your vehicle is factory equipped with
“(Y)”-rated tires, which have a speed rating
of over 186 mph (300 km/h).
Winter driving instructions
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,
move gear selector lever to neutral
positionN. Try to keep the vehicle under
control by corrective steering action.
!
Avoid spinning of a drive wheel. This may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.
Warning!
G
Even when permitted by law, never operate
a vehicle at speeds greater than the maxi-
mum 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.i
For information on tire speed rating for win-
ter tires, see “Winter tires*” (
page 292).
For additional general information on tire speed
markings on tire sidewall, see “Tire speed rating”
(
page 279).
i
For information on driving with snow chains,
see “Snow chains” (
page 293).
Warning!
G
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 control loss.

259 Operation
Tires and wheels
Tires and wheels
For safety reasons, only use tires and rims
which have been tested and approved by
Mercedes-Benz for use on SLR vehicles.
Contact an authorized Mercedes-Benz
Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and
purchase.
Important guidelines

For the first 100 miles (160 km) avoid
high-speed cornering. Do not exceed a
speed of 125 mph (200 km/h).
1


Only use sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


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
required.
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. Contact an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension
components can be damaged.


The operating clearance of the wheels
and the tires may no longer be correct.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
Have worn or damaged tires replaced in
pairs (front pair or rear pair) an make sure
the tires rotate in the direction specified
(page 262). Otherwise, the driving stabili-
ty of the vehicle will be adversely affected,
especially when driving at high speeds.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on re-
treads. The operating safety of the vehicle
cannot be assured when such tires are used.
!
A wheel change should only be carried out
at an authorized Mercedes-Benz Center. Other-
wise there is a danger of damaging the vehicle by
jacking it up incorrectly.
1Please always drive carefully and obey applicable
speed limits.

277 Operation
Tires and wheels
Tire size designation, load and speed
rating
1Tire width
2Aspect ratio in %
3Radial tire code
4Rim diameter
5Tire load rating
6Tire speed ratingGeneral:
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 277) indicates
the nominal tire width in mm. Aspect ratio
The aspect ratio2 (
page 277) 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 277) 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 279).
i
For illustration purposes only. Actual data
on tires is specific to each vehicle and may vary
from data shown in above illustration.

278 OperationTires and wheelsRim diameter
The rim diameter4 (
page 277) 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 277) 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 1356 lb
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 282) where the maximum load as-
sociated with the load index is indicated in
kilograms and lb.For additional information on tire load
rating, see “Load identification”
(
page 280).
Warning!
G
The tire load rating must always be at least
half of the GAWR (
page 287) of your
vehicle. Otherwise tire failure may be the re-
sult 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.
Warning!
G
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the Tire and Loading
Information placard located on the driver’s
door B-pillar. Overloading the tires can over-
heat them, possibly causing a blowout.
Overloading the tires can also result in han-
dling or steering problems, or brake failure.
i
Tire load rating5 (
page 277) and tire
speed rating6 (
page 277) are also referred
to as “service description”.

281 Operation
Tires and wheels
No specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
XL or 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 manufacture
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

282 OperationTires and wheelsDOT (D
epartment o
f T
ransportation)
A tire branding symbol1 (
page 281)
which denotes the tire meets require-
ments of the U.S. Department of
Transportation.
Manufacturer’s identification mark
The manufacturer’s identification mark2
(
page 281) 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 259).
Tire size
The code3 (page 281) indicates the
tire size.Tire type code
The code4 (
page 281) 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 281)
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, “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.i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

286 OperationTires and wheelsTire 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.
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), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another 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 three hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

288 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
Recommended tire inflation pressure for
normal driving conditions is listed on the
Tire and Loading Information placard locat-
ed on the driver’s door B-pillar. Provides
best handling, tread life and riding com-
fort. If so equipped, supplemental informa-
tion 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 lb) 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.

386 Technical dataRims and tiresMixed size tires
Only Mercedes-Benz SLR McLaren Roadster:
Turbine-style
10-spoke-style*
Front axle:Rims (light alloy)
9 J x 19
9 J x 18
Wheel offset
1.83 in (46.5 mm)
1.77 in (45 mm)
Summer tires (radial-ply tires)
255/35 ZR19 (96Y) XL
1
245/40 ZR18 (93Y)
Rear axle:Rims (light alloy)
11
1/2 J x 19
11
1/2 J x 18
Wheel offset
1.73 in (44 mm)
1.73 in (44 mm)
Summer tires (radial-ply tires)
295/30 ZR19 (100Y) XL
1
295/35 ZR18 (99Y)
1
1Must not be used with snow chains.!
Only use Michelin tires of the sizes and
types noted above. They are the only tires
approved for use on the Mercedes-Benz SLR
McLaren Roadster. Use of tires not specially ap-
proved for the Mercedes-Benz SLR McLaren
Roadster could result in unanticipated perfor-
mance characteristics. For more information,
contact an authorized Mercedes-Benz Center.