MERCEDES-BENZ SL65AMG 2008 R230 Owner's Manual

290 Operation
Engine compartment
Battery
Your vehicle is equipped with two
batteries:

The starter battery (located in the
engine compartment)

The battery for electrical consumers
(located in the trunk)
These batteries should always be suffi-
ciently charged in order to achieve their
rated service life. Refer to Maintenance
Booklet for battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to
have the battery charge checked more
frequently.
When replacing batteries, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
Warning!G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills imme-
diately with clear water. Contact
a physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.

291 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.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 of less than
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.
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.

292 Operation
Tires and wheels
Tire 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 pres-
sure” (
page 300).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:

excessive treadwear (page 293)

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
6 years, regardless of the remaining tread.

293 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 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 approx-
imately
1/16in (1.6 mm), at which point the
tire is considered worn and should be re-
placed.
Recommended minimum tire tread depth:

Summer tires 1/8in (3 mm)

Winter tires 1/6in (4 mm)
1TWI (T
read Wear Indicator)
The treadwear indicator appears as a solid
band across the tread.Storing tires
Cleaning tiresWarning!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 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. Pro-
tect tires from contact with oil, grease and gaso-
line.
!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.

294 Operation
Tires and wheels
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.
2) 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.
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
regards to loading your vehicle.
iSpare wheels may be mounted against the
direction of rotation (spinning) even with a unidi-
rectional tire for temporary use only until the reg-
ular drive wheel has been repaired or replaced.
Always observe and follow applicable temporary
use restrictions and speed limitations indicated
on the spare wheel.

295 Operation
Tires and wheels
Tire and Loading InformationTire and Loading Information placard
1Load limit information on the Tire and
Loading Information placard
The Tire and Loading Information placard
showing the load limit information is
located on the driver’s door B-pillar
(
page 294).
Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kilograms or XXX
lbs.” on the Tire and Loading
Information 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 294).
Warning!G
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.
iData 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 illustration
below. Refer to Tire and Loading Information
placard on vehicle for actual data specific to your
vehicle.

296 Operation
Tires and wheels
1Seating capacity information on the
Tire and Loading Information placardSteps 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
Information 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 1 400 lbs. and there will
be five 150 lbs. passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs.
(1 400 - 750 (5 x 150) = 650 lbs.)
iData 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 illustration
below. Refer to Tire and Loading Information
placard on vehicle for actual data specific to your
vehicle.

297 Operation
Tires and wheels
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 299).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 1 500 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
Information placard (
page 295).

298 Operation
Tires and wheels
The higher the weight of all occupants, the
less cargo and luggage load capacity is
available.
For more information, see “Trailer tongue
load” (
page 299).
ExampleCombined weight limit of
occupants and cargo
from Tire and Loading
Information placardNumber of
occupants
(driver and
passengers)Occupants weight Combined
weight of all
occupantsAvailable cargo/luggage and trailer
tongue weight (total load limit from
Tire and Loading Information
placard minus combined weight of
all occupants)
11 500 lbs1Occupant 1: 175 lbs175 lbs1 500 lbs - 175 lbs = 1 325 lbs
21 500 lbs2Occupant 1: 175 lbs
Occupant 2: 195 lbs370 lbs1 500 lbs - 370 lbs = 1 130 lbs

299 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 299) 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
label. The certification label can be found
on the driver’s door B-pillar, see “Technical
data” (
page 444).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 299) 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
10 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.