MERCEDES-BENZ SLR 2009 R199 Owner's Manual

261 Operation
Tires and wheels
Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style


Tire inflation pressure


Distance driven
Tread depth
Do not allow your tires to wear down too
far. Adhesion properties on wet roads are
sharply reduced at tread depths of less
than 1/8in (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 approximately
1/16in (1.6 mm), at which
point the tire is considered worn and
should be replaced.
Recommended minimum tire tread depth:


Summer tires
1/8in (3 mm)


Winter tires
1/6in (4 mm)
1TWI (T
read W
ear I
ndicator)
The treadwear indicator appears as a solid
band across the tread.
Warning!
G
Tires should be replaced after 6 years,
regardless of the remaining tread.
Warning!
G
Although the applicable federal motor safety
laws consider a tire to be worn when the
treadwear indicators (TWI) become visible at
approximately
1/16in (1.6 mm), we recom-
mend that you do not allow your tires to
wear down to that level. As tread depth
approaches
1/8in (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.

262 OperationTires and wheelsStoring tires
Cleaning tires
Direction of rotation
Unidirectional tires offer added advan-
tages, such as better hydroplaning perfor-
mance. 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 (spinning) of
the tire.
Loading the vehicle
Two labels on your vehicle show how much
weight it may properly carry.
1) The Tire and Loading Information
placard can be found on the driver’s
door B-pillar. This placard tells you im-
portant information about the number
of people that can be in the vehicle and
the total weight that can be carried in
the vehicle. It also contains information
on the proper size and recommended
tire inflation pressures for the original
equipment tires on your vehicle.
!
Keep unmounted tires in a cool, dry place
with as little exposure to light as possible.
Protect tires from contact with oil, grease and
gasoline.
!
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.
Warning!
G
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.
Warning!
G
19" turbine-style wheels:
The wheels must be mounted corresponding
to the labelling on the inside of the rim,
where LEFT refers to the left-hand side of
the vehicle and RIGHT to the right-hand side
of the vehicle, both seen in direction of trav-
el. When unidirectional tires are mounted,
make sure that they rotate in the direction
specified. Otherwise, the driving stability of
the vehicle will be adversely affected,
especially when driving at high speeds.

263 Operation
Tires and wheels
2) The certification label found on the
driver’s door A-pillar (
page 382) tells
you about the gross weight capacity of
your vehicle, called the Gross Vehicle
Weight Rating (GVWR). The GVWR in-
cludes the weight of the vehicle, all
occupants, fuel and cargo. The certifi-
cation label also tells you about the
front and rear axle weight capacity,
called the Gross Axle Weight Rating
(GAWR). The GAWR is the total allow-
a b l e w e i g h t t h a t c a n b e ca r r i e d b y a s i n -
gle axle (front or rear). Never exceed
the GVWR or GAWR for either the front
axle or rear axle.
1Driver’s door B-pillar
Following is a discussion on how to work
with the information contained on the Tire
and Loading Information placard with re-
gards to loading your vehicle.Tire and Loading Information
Tire and Loading Information placard
Warning!
G
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the driv-
er’s door B-pillar. 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.i
Data 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 illustrations
below. Refer to Tire and Loading Information
placard on vehicle for actual data specific to your
vehicle.

264 OperationTires and wheels1Load limit information on the Tire and
Loading Information placard
The Tire and Loading Information placard
showing the load limit information is locat-
ed on the driver’s door B-pillar.
Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kilograms or XXX
lbs.” on this Tire and Loading Informa-
tion 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
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 the
seating capacity is located on the driver’s
door B-pillar (
page 263).
1Seating capacity on the Tire and
Loading Information placard
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”.
Step 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 Infor-
mation placard.
i
Data shown on Tire and Loading Information
placard example are for illustration purposes
only. Seating data are specific to each vehicle
and may vary from data shown in the illustrations
below. Refer to Tire and Loading Information
placard on vehicle for actual data specific to your
vehicle.

265 Operation
Tires and wheels
Step 2
Determine the combined weight of the
driver and passengers that will be
riding in your vehicle.
Step 3

Subtract the combined weight of the
driver and passengers from
XXX kilograms or XXX lbs.
Step 4

The resulting figure equals the avail-
able amount of cargo and luggage load
capacity. For example, if the “XXX”
amount equals 1400 lbs and there will
be five 150 lbs passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs
(1400 - 750 (5 x150) = 650 lbs).Step 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.
Step 6 (if applicable)

If your vehicle will be towing a trailer,
load from your trailer will be trans-
ferred to your vehicle. Consult this
manual to determine how this reduces
the available cargo and luggage load
capacity of your vehicle (
page 267).The following table shows examples on
how to calculate total and cargo load
capacities with varying seating configura-
tions and number and size of occupants.
The following examples use a load limit
of 1500 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 Informa-
tion placard (
page 264).

266 OperationTires and wheelsThe higher the weight of all occupants, the
less cargo and luggage load capacity is
available.
For more information, see “Trailer tongue
load” (
page 267).
Example
Combined weight
limit of occupants
and cargo from Tire
and Loading Infor-
mation placard
Number of
occupants
(driver and
passengers)
Occupants weight
Combined
weight of all
occupants
Available cargo/luggage and trailer
tongue weight (total load limit from Tire
and Loading Information placard minus
combined weight of all occupants)
1
1500 lbs
1
Occupant 1: 175 lbs
175 lbs
1500 lbs - 175 lbs = 1325 lbs
2
1500 lbs
2
Occupant 1: 175 lbs
Occupant 2: 195 lbs
370 lbs
1500 lbs - 370 lbs = 1130 lbs

267 Operation
Tires and wheels
Certification label
Even after careful determination of the
combined weight of all occupants, cargo
and the trailer tongue load (if applicable)
(page 267) as to not exceed the permis-
sible load limit, you must make sure that
your vehicle never exceeds the Gross Vehi-
cle 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 la-
bel. The certification label can be found on
the driver’s door A-pillar, see “Technical
data” (
page 382).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 267) must never exceed the
GVWR.
Gross Axle Weight Rating (GAWR): The to-
tal allowable weight that can be carried by
a single axle (front or rear).
To assure that your vehicle does not ex-
ceed 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 ap-
plicable, trailer fully loaded) weighed on a
suitable commercial scale.Trailer tongue load
The tongue load of any trailer is an impor-
tant 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 ten
percent 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 recom-
mend trailer towing with your vehicle.

268 OperationTires and wheelsRecommended tire inflation pressure
Your vehicle is equipped with the Tire and
Loading Information placard located on
the driver’s door B-pillar (
page 263).
The tire inflation pressure should be
checked regularly and should only be ad-
justed on cold tires. The tires can be con-
sidered cold if the vehicle has been parked
for at least three hours or driven less than
one mile (1.6 km).
Follow recommended cold tire inflation
pressures listed on the Tire and Loading
Information placard on the driver’s door
B-pillar.
Keeping the tires properly inflated
provides the best handling, tread life and
riding comfort.In addition to the Tire and Loading Informa-
tion placard on the driver’s door B-pillar,
also consult the tire inflation pressure la-
bel (if available) on the fuel filler flap for
any additional information pertaining to
special driving situations. For more infor-
mation, see “Important notes on tire infla-
tion pressure” (
page 269).
Warning!
G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely 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
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the driv-
er’s door B-pillar. 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.
i
Data shown on Tire and Loading Information
placard example are for illustration purposes
only. Tire data are specific to each vehicle and
may vary from data shown in the illustrations
below. Refer to Tire and Loading Information
placard on vehicle for actual data specific to your
vehicle.

269 Operation
Tires and wheels
1Tire and Loading Information placard
with recommended cold tire inflation
pressures
The Tire and Loading Information placard
lists the recommended cold tire inflation
pressures for maximum loaded vehicle
weight. The tire inflation pressures listed
apply to the tires installed as original
equipment.Important notes on tire inflation
pressure
Tire temperature and tire inflation pressure
are also increased while driving, depending
on the driving speed and the tire load.
If you will be driving your vehicle at high
speeds of 155 mph (250 km/h) or higher,
where it is legal and conditions allow,
consult the tire inflation pressure label on
the inside of the fuel filler flap (if available)
on how to adjust the cold tire inflation
pressure. If you do not adjust the tire infla-
tion pressure, excessive heat can build up
and result in sudden tire failure.If your vehicle is not equipped with the tire
inflation pressure label on the inside of the
fuel filler flap, contact your PLM or any au-
thorized Mercedes-Benz Center for proper
tire inflation pressure.
Be sure to readjust the tire inflation
pressure for normal driving speeds. You
should wait until the tires are cold before
adjusting the tire inflation pressure.
Some vehicles may have supplemental tire
inflation pressure information for vehicle
loads less than the maximum loaded vehi-
cle condition. If such information is provid-
ed, it can be found on the tire inflation
pressure label located on the inside of the
fuel filler flap.
Warning!
G
If the tire inflation pressure drops
repeatedly:

Check the tires for punctures from
foreign objects.


Check to see whether air is leaking from
the valves or from around the rim.
i
Driving comfort may be reduced when the
tire inflation pressure is adjusted to the value for
speeds above 155 mph (250 km/h) as specified
on the tire inflation pressure label located on the
inside of the fuel filler flap.

270 OperationTires and wheelsTire inflation pressure changes by approxi-
mately 1.5 psi (0.1 bar) per 18°F (10°C) of
air temperature change. Keep this in mind
when checking tire inflation pressure
where the temperature is different from
the outside temperature.
Checking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least 3 hours or driven
less than 1 mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than 3 hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise the tire will be
underinflated.
Warning!
G
Follow recommend tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely 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
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight 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. Overload-
ing the tires can also result in handling or
steering problems, or brake failure.