2004 MERCEDES-BENZ SL55AMG tire pressure

243 Operation
Driving instructions
Tires
Tread wear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and be-
come visible at a tread depth of approxi-
mately
1/16
in (1.6 mm), at which point
the tire is considered worn and should be
replaced.The tread wear indicator appears as a solid
band across the tread.
Specified tire pressures must be main-
tained. This applies particularly if the tires
are subjected to extreme operating condi-
tions (e.g. high speeds, heavy loads, high
ambient temperatures).
Hydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur, even
at low speeds and with new tires. Reduce
vehicle speed, avoid track grooves in the
road and apply brakes cautiously in the
rain.
Warning!
G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have it towed to the nearest
Mercedes-Benz Center or tire dealer for re-
pairs.
Warning!
G
Although the applicable federal motor vehi-
cle safety laws consider a tire to be worn
when the tread wear indicators (TWI) be-
come visible at approximately
1/16in
(1.6 mm), we recommend that you do not al-
low 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.
Warning!
G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.

252 OperationAt the gas stationCheck regularly and before a long trip
1Windshield washer and headlamp
cleaning system
For information on refilling the reser-
voir, see “Windshield washer system
and headlamp cleaning system”
(
page 261).
2Brake fluid
For information on brake fluid, see “Fu-
els, coolants, lubricants, etc.”
(page 386).3Coolant level
For information on coolant, see “Cool-
ant” (
page 258).
Brake fluidEngine oil level
For more information on engine oil, see
“Checking engine oil level with the control
system” (
page 255).
Opening hood see (
page 253).
Vehicle lighting
Check function and cleanliness. For more
information, see “Replacing bulbs”
(
page 331).
Exterior lamp switch see “Switching on
headlamps” (
page 46).
Tire inflation pressure
For information on tire inflation pressure,
see “Checking tire inflation pressure”
(
page 263).
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks immediately. Noti-
fy an authorized Mercedes-Benz Center
immediately. Do not add brake fluid as
this will not solve the problem. For
more information, see the “Practical
hints” section (
page 301).

262 OperationTires and wheels
Tires and wheelsSee an authorized Mercedes-Benz Center
for information on tested and recommend-
ed rims and tires for summer and winter
operation. They can also offer advice con-
cerning tire service and purchase.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
See an authorized Mercedes-Benz Center
for information on tested and recommend-
ed 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 pressure loss or damage the
tire beads.


If vehicle is heavily loaded, check tire
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 compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires is no longer guaran-
teed.
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 re-
sult in the bolts loosening and may lead to
an accident.

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

Driving style


Tire pressure


Distance driven
Direction of rotation
Unidirectional tires offer added advantag-
es, such as better hydroplaning perfor-
mance. To benefit, however, you must
ensure that the tires rotate in the direction
specified.
An arrow on the sidewall indicates the in-
tended direction of rotation of the tire.
Checking tire inflation pressure
Regularly check your tire pressure at inter-
vals of no more than 14 days.
Correct the tire pressure only when tires
are cold.
If the tires are warm, you should only cor-
rect the tire pressure if it is too low for cur-
rent operating conditions.
A table on the fuel filler flap lists the spec-
ified tire inflation pressures for warm and
cold tires as well as for various operating
conditions.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.!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.
Warning!
G
If the tire pressure drops repeatedly:

Check the tires for punctures from for-
eign objects.


Check to see whether air is leaking from
the valves or from around the rim.

264 OperationTires and wheelsTire pressure changes by approximately
1.5 psi (0.1 bar) per 18°F (10°C) of air
temperature change. Keep this in mind
when checking tire pressure where the
temperature is different from the outside
temperature.
The tire temperature and with it the tire
pressure is increased also while driving,
depending on the driving speed and the
tire load.Checking tire pressure electronically*
The tire inflation pressure monitor only
functions on wheels that are equipped with
the proper electronic sensors. It monitors
the tire inflation pressure, as selected by
the driver, in all four tires. A warning is is-
sued to alert you to a decrease in pressure
in one or more of the tires.
Tire pressure inquiries are made using the
multifunction display (
page 127). The
present inflation pressures are displayed
only after a few minutes travel time.
You can select the unit of measure used for
the tire inflation pressure by changing the
setting in the control system (
page 147).
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
maximum values or inflate tires below
the minimum values listed in the fuel
filler flap.
Warning!
G
Follow recommended inflation pressures.
Do not overinflate tires. Overinflated tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.

265 Operation
Tires and wheels

Switch on ignition.

Make sure you are viewing the stan-
dard display menu (
page 127).

Press k button until the current in-
flation pressures for each tire appear in
the tachometer display field.iPossible differences between the read-
ings of a tire pressure gauge of an air
hose, e.g. gas station equipment, and
the vehicle’s control system can occur.
The readings issued by the control sys-
tem are more precise.
Warning!
G
The tire inflation pressure monitor does not
indicate a warning for wrongly selected in-
flation pressures. Always adjust tire inflation
pressure according to the label on the fuel
filler flap.
The tire inflation pressure monitor is not
able to issue a warning due to a sudden dra-
matic loss of pressure (e.g. tire blowout
caused by a foreign object). In the event of
a sudden loss of pressure, bring the vehicle
to a halt by carefully applying the brakes and
avoiding abrupt steering maneuvers.
Warning!
G
Follow recommend tire pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the tire inflation pressure moni-
tor to malfunction.

266 OperationTires and wheelsActivating the tire inflation pressure
monitor
You must activate the tire inflation pres-
sure monitor in the following cases:

if you have changed the tire pressure


if you have replaced the wheels or tires


if you have installed new wheels or
tires

Make sure the tire pressure is set cor-
rectly.

Press the k button on the multi-
function steering wheel until the infla-
tion pressure of each tire appears in
the right display field.

Press the reset button (
page 22).
The following message will appear in
the speedometer display field:
Monitor current tire pressure?


Press æ button.
The following message will appear in
the speedometer display field:Tire pressure displayed
after
driving a few mins.
Reactivate w/
R-button
If you wish to cancel activation:
Press ç button.
If the following message appears in the
speedometer display field:
Reactivate tire press. monit.


Re-start the activation of the tire infla-
tion pressure monitor.
If the following message appears in the
speedometer display field:
Tire pressure

Check tires!


Re-start the activation of the tire infla-
tion pressure monitor.
iIf transporting a deflated road wheel or
additional wheel sensors in the vehicle,
the tire inflation pressure monitor
should not be reactivated until the de-
flated wheel or additional wheel sen-
sors have been removed from the
vehicle. Otherwise, the deflated wheel
or additional sensors could confuse the
tire inflation pressure monitor system
and cause it to malfunction.

267 Operation
Tires and wheels
Rotating wheels
On vehicles with the same wheel size all
around, wheels can be rotated every 3 000
to 6 000 miles (5 000 to 10 000 km), or
sooner if necessary, according to the de-
gree of tire wear. The same direction of tire
rotation must be retained.
Rotate the wheels before the characteris-
tic tire wear pattern becomes visible
(shoulder wear on front wheels and tread
center wear on rear wheels).Thoroughly clean the inner side of the
wheels after each rotation. Check and en-
sure proper tire inflation pressure, activat-
ing the tire inflation pressure monitor if
necessary. For information on wheel change, see the
“Practical hints” section (
page 323) and
(
page 339).
Warning!
G
Rotate front and rear wheels only if they are
of the same size.
!If your vehicle is equipped with a tire in-
flation pressure monitor*, there are
electronic components built into the
wheel.
Do not use mounting tools in the area
of the valve as they could damage the
electronic components.
To prevent damage or incorrect instal-
lation, have the tires changed at an au-
thorized Mercedes-Benz Center.
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
96 lb-ft (130 Nm).
Only use genuine Mercedes-Benz wheel
bolts specified for your vehicle's rims.