2008 MERCEDES-BENZ SL550 inflation pressure

320 Operation
Tires and wheels
Always follow the recommended tire
inflation pressure (
page 300) for proper
tire inflation. Uniform Tire Quality Grading Standards (U.S. vehicles)
Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.
1Treadwear
2Traction
3Temperature resistanceQuality grades can be found, where appli-
cable, on the tire sidewall between tread
shoulder and maximum section width. For
example:
All passenger car tires must conform to
federal safety requirements in addition to
these grades.
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 over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
TreadwearTractionTemperature
200AAA

323 Operation
Tires and wheels
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 3 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.DOT (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GVW (G
ross Vehicle Weight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GVW must never exceed the
GVWR indicated on the certification label
located on the driver’s door B-pillar.GVWR (G
ross Vehicle Weight Rating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on
certification label located on the driver’s
door B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kPa to 1 psi; another metric unit for air
pressure is bars. There are 100 kilopascals
(kPa) to 1 bar.
Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit and production options
weight.

324 Operation
Tires and wheels
Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.
Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.PSI (Pounds per square inch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
The recommended tire inflation pressure is
listed on Tire and Loading Information
placard located on driver’s door B-pillar for
normal driving conditions and provides
best handling, tread life and riding com-
fort. If so equipped, supplemental informa-
tion pertaining to special driving situations
can be found on the tire inflation pressure
label on the inside of the fuel filler flap.
Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.TIN (Tire Identification Number)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.

326 Operation
Tires and wheels
If applicable to your vehicle’s tire configu-
ration, tires can be rotated according to
the tire manufacturer’s recommended in-
tervals in the tire manufacturer’s warranty
pamphlet located in your vehicle literature
portfolio. If none is available, tires should
be rotated every 3 000 to 6 000 miles
(5 000 to 10 000 km), or sooner if neces-
sary, according to the degree of tire wear.
The same rotation (spinning) direction
must be maintained (
page 294).
Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.For information on wheel change, see the
“Practical hints” section (
page 400) and
(
page 417).
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.

355 Practical hints
What to do if …
ProblemPossible cause/consequenceSuggested solution
HUSA only:
Combination low tire pressure/
TPMS malfunction telltale for
the TPMS illuminates continu-
ously.
Canada only:
Low tire pressure telltale for the
Advanced TPMS* illuminates
continuously.The TPMS (USA only) or Advanced TPMS*
(Canada only) detects a loss of pressure in
at least one tire.Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers. Observe the traffic situation
around you.
Read and observe messages in the
multifunction display.
If the tire inflation pressure in the respec-
tive tire(s) has (have) been corrected,
the combination low tire pressure/TPMS
malfunction telltale goes out after a few
minutes of driving.
HUSA only:
Combination low tire pressure/
TPMS malfunction telltale for
the TPMS flashes for
60 seconds and then stays illu-
minated.There is a malfunction in the TPMS.Read and observe messages in the
multifunction display.
Have the TPMS checked by an
authorized Mercedes-Benz Center.
After the malfunction has been remedied,
the combination low tire pressure/TPMS
malfunction telltale goes out after a few
minutes of driving.
(Continued on next page)

356 Practical hints
What to do if …
Warning!G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
Tire and Loading Information placard on the
driver’s door B-pillar (
page 294) or, if
available, the tire inflation pressure label on
the inside of the fuel filler flap (
page 279).
If your vehicle has tires of a different size
than the size indicated on the Tire and Load-
ing Information placard or, if available, the
tire inflation pressure label, you should de-
termine the proper tire inflation pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated.
Accordingly, when the low tire pressure tell-
tale illuminates, you should stop and check
your tires as soon as possible, and inflate
them to the proper pressure. Driving on a
significantly underinflated tire causes the
tire to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’s responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of
the TPMS low tire pressure telltale.USA only:
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately
one minute and then remain continuously
illuminated. This sequence will continue
upon subsequent vehicle start-ups as long
as the malfunction exists. When the mal-
function indicator is illuminated, the system
may not be able to detect or signal low tire
pressure as intended.
TPMS malfunctions may occur for a variety
of reasons, including the installation of
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from
functioning properly. Always check the
TPMS malfunction telltale after replacing
one or more tires or wheels on your vehicle
to ensure that the replacement or alternate
tires and wheels allow the TPMS to continue
to function properly.

361 Practical hints
What to do if …
Text messages
Left displayRight displayPossible cause/consequencePossible solution
Check tires,
then restart
Run Flat Indicator
.
There was a warning message about a
loss in the tire inflation pressure and
the Run Flat Indicator has not been
restarted yet.Make sure that the correct tire inflation
pressure is set for each tire.
Then restart the Run Flat Indicator.
Tire Pressure
Check TiresThe Run Flat Indicator indicates that
the pressure is too low in one or more
tires.Carefully bring the vehicle to a halt, avoid-
ing abrupt steering and braking maneu-
vers. Observe the traffic situation around
you.
Check and adjust tire inflation pressure as
required (
page 302).
If necessary, change the wheel
(
page 417).
Restart the Run Flat Indicator after adjust-
ing the tire inflation pressure values
(
page 304).
ABCMalfunction
Stop CarYou have started driving although the
vehicle level is still too low.
The vehicle is being raised. The ABC
message goes out after a few seconds.Stop your vehicle in a safe location or as
soon as it is safe to do so.
Wait until the message disappears from
the multifunction display.
You may then drive off.

374 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
Tire pressuredisplayed after
driving for
a few minutes.Vehicles with Advanced TPMS*:
The tire inflation pressure is being
checked.Drive the vehicle for a few minutes.
Tire Pressure MonitorInoperativeThe TPMS or Advanced TPMS* is
malfunctioning.Have the TPMS or Advanced TPMS*
checked by an authorized
Mercedes-Benz Center.
Tire Pressure MonitorInoperative
No Wheel SensorsThere are wheels without appropriate
wheel sensors mounted (e.g. winter
tires).Have the TPMS or Advanced TPMS*
checked by an authorized
Mercedes-Benz Center.
Have appropriate wheel sensors in-
stalled by an authorized Mercedes-Benz
Center.
Tire Pressure Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more sensors defect
(e.g. empty sensor battery).
The respective tire is indicated by
---
instead of the tire inflation pressure in
the multifunction display.
Have Advanced TPMS* checked by an
authorized Mercedes-Benz Center.
Have appropriate wheel sensors in-
stalled by an authorized Mercedes-Benz
Center.