MERCEDES-BENZ SL55AMG 2005 R230 Owner's Manual

279 Operation
Tires and wheels
Tires and wheels
See 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.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. The operating safety of the
vehicle cannot be assured when such tires
are used.
See an authorized Mercedes-Benz Center
for information on tested and
recommended rims and tires for summer
and winter operation.
Important guidelines

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


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


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.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See 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.
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.

280 OperationTires and wheelsTire care and maintenance
Regularly check your tire inflation pressure
at least once a month. For more informa-
tion on checking tire inflation pressure see
“Recommended tire inflation pressure”
(page 288).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:


excessive tread wear (
page 281)


cord or fabric showing through the
tire’s rubber


bumps, 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
The service life of a tire is dependent upon
varying factors including but not limited to:


Driving style


Tire inflation pressure


Distance driven
Warning!
G
Regularly check the tires for damage. Dam-
aged 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 badly worn, or if the tires have
sustained damage, replace them.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.

281 Operation
Tires and wheels
Tread depth
Do not allow your tires to wear down too
far. Adhesion properties on wet roads are
sharply reduced at tread depths under 1⁄8in (3 mm).
Tread wear 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 approx-
imately
1/16
in (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 tread wear indicator appears as a solid
band across the tread.Storing tires
Cleaning tires
Warning!
G
Although the applicable federal motor safety
laws consider a tire to be worn when the
tread wear indicators (TWI) become visible
at approximately
1/16in (1.6 mm), we rec-
ommend 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 re-
duced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
!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.

282 OperationTires and wheelsDirection 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.

The Tire and Loading Information
placard (Example A) or the Vehicle Tire
Information placard (Example B) can be
found on the driver’s door B-pillar. This
placard tells you important 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.


The Certification label, also found on
the driver’s door B-pillar tells you about
the gross weight capacity of your vehi-
cle, 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.
iSpare 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 tempo-
rary use restrictions and speed limita-
tions indicated on the spare wheel.

283 Operation
Tires and wheels
1Driver’s door B-pillar
Following is a discussion on how to work
with the information contained on the two
placards with regards to loading your vehi-
cle.Tire and Loading Information
Your vehicle is equipped with either the
Tire and Loading Information placard
(Example A) or the Vehicle Tire Information
placard (Example B). Placard (Example A)
1Load limit information on the Tire and
Loading Information placard
The placard showing the load limit informa-
tion is located on the driver’s door B-pillar.
If your vehicle is equipped with the Tire and
Loading Information placard (Example A),
locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kilograms or XXX lbs.”
on this placard. The combined weight of all
occupants, cargo / luggage and trailer
tongue load (if applicable) should never
exceed the weight referenced in that
statement.
Warning!
G
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the 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.iData shown on placard examples is for
illustration purposes only. Load limit
data is specific to each vehicle and may
vary from data shown in the illustra-
tions below. Refer to placard on vehicle
for actual data specific to your vehicle.

284 OperationTires and wheelsPlacard (Example B)
1Load limit information on the Vehicle
Tire Information placard
The placard showing the load limit informa-
tion is located on the driver’s door B-pillar.
If your vehicle is equipped with the Vehicle
Tire Information placard (Example B),
locate the heading “Vehicle Capacity
Weight” on this placard. The combined
weight of all occupants, cargo/luggage
and trailer tongue (if applicable) should
never exceed the weight listed next to
vehicle capacity weight.Seating capacity
The seating capacity gives you important
information on the number of occupants
that can be in the vehicle. Observe front
and rear seating capacity. Your vehicle is
equipped with either placard Example A or
placard Example B located on the driver’s
door B-pillar (
page 283).
Placard (Example A)1Seating capacityPlacard (Example B)1Seating capacity
iData shown on placard examples is for
illustration purposes only. Seating data
is specific to each vehicle and may vary
from data shown in the illustrations
below. Refer to placard on vehicle for
actual data specific to your vehicle.

285 Operation
Tires and wheels
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 (Vehicles equipped with placard
Example A)
Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kg or XXX lbs.” on
your vehicle’s placard.
Step 1 (Vehicles equipped with placard
Example B)

Locate the heading “Vehicle Capacity
Weight” on your vehicle’s placard.
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 kilo-
grams 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 287).
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 placard (
page 283).

286 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 287).
Example
Combined
weight limit
of occu-
pants and
cargo from
placard
Number of
occupants
(driver and
passengers)
Seating
configura-
tion
Occupants weight
Combined
weight of all
occupants
Available cargo/luggage and trailer
tongue weight (total load limit or
vehicle capacity weight from plac-
ard minus combined weight of all
occupants)
1
1500 lbs
5
front: 2
rear: 3
Occupant 1: 150 lbs
Occupant 2: 180 lbs
Occupant 3: 160 lbs
Occupant 4: 140 lbs
Occupant 5: 120 lbs
750 lbs
1500 lbs - 750 lbs = 750 lbs
2
1500 lbs
3
front: 1
rear: 2
Occupant 1: 200 lbs
Occupant 2: 190 lbs
Occupant 3: 150 lbs
540 lbs
1500 lbs - 540 lbs = 960 lbs
3
1500 lbs
1
front:1
Occupant 1: 150 lbs
150 lbs
1500 lbs - 150 lbs = 1350 lbs

287 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 287) 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 B-pillar, see “Technical
data” (
page 418).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 287) 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 every-
thing 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.

288 OperationTires and wheelsRecommended tire inflation pressure
Your vehicle is equipped with either the
Tire and Loading Information placard
(Example A) or the Vehicle Tire Information
placard (Example B) located on the driver’s
door B-pillar (
page 283).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 placard.
Keeping the tires properly inflated
provides the best handling, tread life and
riding comfort.
In addition to the tire placard on the
driver’s door B-pillar, also consult the fuel
filler flap for any additional information
pertaining to special driving situations. For
more information, see “Important notes on
tire inflation pressure” (
page 289).Placard (Example A)
1Tire and Loading Information placard
with recommended cold tire inflation
pressures
Placard (Example A) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.
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 over-
heated.
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.
iData shown on placard examples is for
illustration purposes only. Tire data is
specific to each vehicle and may vary
from data shown in the illustrations
below. Refer to placard on vehicle for
actual data specific to your vehicle.