2009 MERCEDES-BENZ SLR load capacity

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

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.

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”.

283 Operation
Tires and wheels
For more information on tire load rating
(page 278).
For information on calculating total and
cargo load capacities (
page 264).
Maximum tire inflation pressure
1Maximum permissible tire inflation
pressure
This is the maximum permissible tire
inflation pressure for the tire.Always follow the recommended tire
inflation pressure (
page 268) for proper
tire inflation.
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
For illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
Warning!
G
Never exceed the max. tire inflation
pressure. 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.

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.