inflation pressure MERCEDES-BENZ S-Class 2011 W221 Owner's Manual

bags will continue to provide supplemental
crash protection for occupants.
Front air bags
GWarning
Observe "Important safety notes"
(Y page 44).
The front air bags increase protection for the
driver's and front-passenger's head and
chest.
Driver's air bag : deploys in front of the
steering wheel; front-passenger air bag ;
deploys in front of and above the glove box.
They are deployed:
Rin the event of certain frontal impacts
Rif the system determines that air bag
deployment can offer additional protection
to that provided by the seat belt
Rif the seat belt is fastened
Rindependently of other air bags in the
vehicle
If the vehicle overturns, the front air bags are
generally not deployed unless the system
detects high vehicle deceleration in a
longitudinal direction.
Your vehicle has adaptive, two-stage front air
bags. In the event of a collision, the air bag
control unit evaluates the vehicle
deceleration. When the first deployment
threshold is reached, the front air bag is filled
with enough propellant gas to reduce the risk
of injuries. The front air bag is fully deployed
if a second deployment threshold is exceeded
within a few milliseconds.
The deployment of the front-passenger air
bag is also influenced by the weight category
of the front passenger, which is determined
by the Occupant Classification System (OCS)
(Y page 48).
The lighter the passenger side occupant, the
higher the vehicle deceleration rate required
for second stage inflation of the front-
passenger front air bag. In the second stage,
the front air bags are inflated with the
maximum amount of propellant gas available.
In impact situations with deceleration or
acceleration values lower than the vehicle
deceleration or acceleration values preset in
the system, the front air bags are not
deployed. You will then be protected by the
seat belt.
The front-passenger air bag will only deploy
if:
Rthe system, based on the OCS weight
sensor readings, has detected that the
front-passenger seat is occupied.
Rthe 42 indicator lamp in the
center console is not lit, (Y page 48)
Rthe impact exceeds a preset deployment
threshold.
Side impact air bags
GWarning
Observe "Important safety notes"
(Y page 44).
GWarning!
The pressure sensors for side impact air bag
control are located in the doors. Do not
modify any components of the doors or door
trim panels including, for example, the
addition of door speakers.
Improper repair work on the doors or the
modification or addition of components to the
doors create a risk of rendering the side
impact air bags inoperative or causing
unintended air bag deployment. Work on the
46Occupant safetySafety

workshop, e.g. an authorized Mercedes-
Benz Center.
If you leave the vehicle parked up for longer
than six weeks, the vehicle may suffer
damage as a result of lack of use.XVisit a qualified specialist workshop and
seek advice.
Driving tips
General notes on driving
Important safety notes
GWarning!
Please do not forget that your primary
responsibility is to drive the vehicle. A driver’s
attention to the road must always be his/her
primary focus when driving. For your safety
and the safety of others, we recommend that
you pull over to a safe location and stop
before placing or taking a telephone call.
If you choose to use the telephone 21
while
driving, please use the hands-free device and
only use the telephone when road, weather
and traffic conditions permit. Some
jurisdictions prohibit the driver from using a
mobile telephone while driving a vehicle.
Only operate the COMAND 21
(Cockpit
Management and Data System) if road,
weather and traffic conditions permit.
Otherwise, you may not be able to observe
traffic conditions and could endanger yourself
and others.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
Drive sensibly – save fuel
To save fuel, observe the following notes:
XKeep tires at the recommended inflation
pressures.XRemove unnecessary cargo.XRemove the roof rack when not in use.XMaintain a low engine speed until the
engine is warm.XAvoid frequent acceleration and
deceleration.XHave all maintenance work performed at
the service intervals specified in the
Service Booklet or indicated by the service
interval indicator.
Fuel consumption is also increased by driving
in cold weather, in stop-and-go traffic, on
short trips and in mountainous areas.
Drinking and driving
GWarning
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident are greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Pedals
GWarning
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure that the
pedals still have sufficient clearance.
21 Observe all legal requirements.Driving tips319Driving and parkingZ

Display messagesPossible causes/consequences and M SolutionsCruise Control
ohne
Funktion InoperativeCruise control is faulty.XVisit a qualified specialist workshop.Cruise Control
--- mphA condition for activating cruise control has not been met.
You wanted to save a speed of less than 20 mph (30 km/h).XIf the situation allows, drive faster than 20 mph ( 30 km/h) and
save the speed.XCheck the activation conditions for cruise control
( Y page 323).
Tires
GWarning
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 will cause excessive heat build-up
and possibly a fire.
GWarning
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.
Display messagesPossible causes/consequences and M SolutionsTire Pressures
Displayed After
Driving A Few
MinutesThe tire pressure monitor is measuring the tire pressure.XDrive on.
The tire pressures appear in the multifunction display after you
have been driving for a few minutes.Tire Pressure
Monitor
InoperativeThe TPMS is faulty.XVisit a qualified specialist workshop.Tire Pressure
Monitor
Inoperative No
Wheel SensorsThe wheels mounted do not have a suitable tire pressure sensor.
The tire pressure monitor is deactivated.XMount wheels with suitable tire pressure sensors.
The TPMS is activated automatically after driving for a few
minutes.Display messages407On-board computer and displaysZ

inside of the fuel filler flap of your vehicle, if there is one). If your vehicle has tires which are a
different size to those on the tire and load data label or those specified in the tire pressure table,
if there is one, you should determine the correct tire pressure for these tires.
As an added safety feature, your vehicle has been equipped with a tire pressure monitor (TPMS).
An indicator lamp lights up if one or more of your tires are significantly underinflated. Accordingly,
when the low tire pressure indicator lamp lights up, 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.
An excessively low tire pressure also increases fuel consumption, reduces the service life of the
tires and may impair the driving and braking characteristics of the vehicle. Please note that the
TPMS is not a substitute for proper tire maintenance and it is the driver's responsibility to maintain
correct tire pressure, even if underinflation has not reached the level at which the low tire
pressure indicator lamp of the TPMS lights up.
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 combined with the low tire
pressure indicator lamp. When the system detects a malfunction, the indicator lamp will flash
for approximately one minute and then remain illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the malfunction exists. When the malfunction indicator
is lit, 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 incompatible
replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction indicator 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.420Warning and indicator lamps in the instrument clusterOn-board computer and displays

Vehicle equipment
i This manual describes all the standard
and optional equipment of your vehicle
which was available at the time of
purchase. Country-specific differences are
possible. Bear in mind that your vehicle
may not feature all functions described
here. This also refers to safety-related
systems and functions.
Important safety notes
Contact an authorized Mercedes-Benz Center
if you require information on tested and
recommended tires and wheels for summer
and winter driving. Advice on purchasing and
caring for tires is also available there.
GWarning
Replace rims or tires with the same
designation, manufacturer and type as shown
on the original part. For further information
contact an authorized Mercedes-Benz Center.
If incorrectly sized rims and tires are
mounted, the wheel brakes or suspension
components can be damaged. Also, the
operating clearance of the wheels and the
tires may no longer be correct.
GWarning
Worn, old tires can cause accidents. If the tire
tread is worn to minimum tread depth, 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
recommended 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.
GWarning
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possible
damage to your vehicle has occurred, you
should turn on the hazard warning flashers,
carefully slow down, and drive with caution to
an area which is a safe distance from the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle appears
unsafe, have the vehicle towed to the nearest
authorized Mercedes-Benz Center or tire
dealer for repairs.
GWarning
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
might 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.
i Further information about tires and
wheels can be obtained from any
authorized Mercedes-Benz Center.
Mode
Notes on driving
R If the vehicle is heavily laden, check the tire
pressures, and correct them, if necessary.
R When parking your vehicle, make sure that
the tires do not get deformed by the curb
or other obstacles. If it is necessary to drive
over curbs, speed humps or similar
elevations, try to do so slowly and at an
obtuse angle. Otherwise, the tires –
particularly the sidewalls – can get
damaged.
Notes on regularly inspecting wheels
and tires
GWarning
Regularly check the tires for damage.
Damaged tires can cause tire inflation
480ModeTires and wheels

"Technical Data" section to avoid damage
to the vehicle or the wheels.
R Only use snow chains when driving on an
area completely covered by snow. Do not
exceed the maximum permissible speed of
30 mph (50 km/h). Remove the snow
chains as soon as possible when you are no
longer driving on snow-covered roads.
R Local regulations may restrict the use of
snow chains. Applicable regulations must
be observed if you wish to mount snow
chains.
R Snow chains must not be mounted on
emergency spare wheels.
If you intend to mount snow chains, please
bear the following points in mind:
R you may not attach snow chains to all
wheel-tire combinations; see the "Tires and
wheels" section in the "Technical data"
chapter.
R mount snow chains only in pairs and only
on the rear wheels. Observe the
manufacturer's installation instructions.
! If snow chains are mounted on the front
wheels, the snow chains could grind
against the bodywork or components of the
chassis. This could result in damage to the
vehicle or the tires.
! Vehicles with steel wheels
If you wish to mount snow chains to steel
wheels, make sure that you remove the
respective wheels' hubcaps first. The
hubcaps may otherwise be damaged.
i You may wish to deactivate
ESP ®
(Y page 69) when pulling away with
snow chains installed. This way you can
allow the wheels to spin in a controlled
manner, achieving an increased driving
force (cutting action).Tire pressure
Tire pressure specifications
GWarning
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.
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.
You will find a table of recommended tire
pressures on the Tire and Loading
Information placard on the B-pillar on the
driver's side ( Y page 490). You will find a
table of tire pressures for various operating
conditions on the inside of your vehicle's fuel
filler flap.
Use a suitable pressure gauge. The outer
appearance of a tire does not permit any
reliable conclusion about the tire pressure.
On vehicles equipped with the electronic tire
pressure monitor, the tire pressure can be
checked using the on-board computer.
GWarning
Should the tire pressure drop repeatedly:
Tire pressure483Tires and wheelsZ

Make sure that the tire pressure for normal
speeds is adopted again.
Additional specifications of tire pressure
values for loads can also be found on the tire
pressure table on the inside of the fuel filler
flap.
The tire pressure for emergency spare wheels
can be found:
R on the yellow label on the wheel rim of the
emergency spare wheel
R in the "Wheel and tire combinations"
section ( Y page 503) of this Operator's
Manual
R on the Tire and Loading Information placard
on the B-pillar on the driver's side
i The specifications shown in the examples
in the tire pressure tables are only
examples. Tire pressure specifications are
vehicle-specific and may deviate from the
data shown here. The tire pressure
specifications that are valid for your vehicle
can be found on your vehicle's tire pressure
table.
The tire pressures in the tire pressure table
on the inside of the fuel filler flap are valid for
all approved tires installed at the factory,
unless stated otherwise.
Tire pressure table for all approved tires installed
at the factory (example)
If the tire pressure precedes a tire size, the
tire pressure specification is only valid for this
tire size. The vehicle loading conditions
"partially laden" or "fully laden" are specified
using a differing number of persons and
luggage in the table. The actual number of
seats may differ from this.
Tire pressure table with tire sizes (example)
Some tire pressure tables only show the rim
diameter instead of the complete tire size,
e.g. R18 . The rim diameter is a component of
the tire size and can be read from the tire
sidewall ( Y page 496).
Tire pressure too low or too high
Underinflated tires
GWarning
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.
Underinflated tires can:
R wear excessively and/or unevenly
R adversely affect fuel economy
Tire pressure485Tires and wheelsZ

Rfail from being overheated
R adversely affect handling
Overinflated tiresGWarning
Follow recommended tire inflation pressures.
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.
Overinflated tires can:
R adversely affect handling
R wear excessively and/or unevenly
R be more likely to become damaged
R adversely affect ride comfort
R increase stopping distance
Maximum tire pressure
GWarning
Never exceed the maximum 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.
:Maximum permitted tire pressure
(example)
i The actual values for tires are specific to
each vehicle and may deviate from the
values in the illustration.
When adjusting the tire pressures always
observe the recommended tire pressure for
your vehicle ( Y page 483).
Checking tire pressures
Important safety notes
GWarning
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.
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.
486Tire pressureTires and wheels

Check the tire pressure at least once a month.
Only check and correct tire pressures when
the tires are cold ( Y page 483).
Checking the tire pressures manually
In order to determine and adjust the tire
pressures, proceed as follows:
XRemove the valve cap of the tire you wish
to check.XPress the tire pressure gauge securely onto
the valve.XRead the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the driver's side of your vehicle.XIf necessary, increase the tire pressure to
the recommended value ( Y page 483).XIf the tire pressure is too high, release air
by pressing down the metal pin in the valve
using the tip of a pen, for example. Then,
check the tire pressure again using the tire
pressure gauge.XScrew the valve cap onto the valve.XRepeat the steps for the other tires.
Tire pressure monitor
Important safety notes
If a tire pressure monitor is installed, the
vehicle's wheels have sensors installed that
monitor the tire pressures in all four tires. The
tire pressure monitor warns you when the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct wheel electronics units are installed
in all wheels.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss/malfunctions (USA)
or pressure loss (Canada). Depending on how
the warning lamp flashes or lights up, a tire
pressure that is too low or a malfunction in
the tire pressure monitor is displayed:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
R USA only: if the warning lamp flashes for
60 seconds and then remains lit constantly,
the tire pressure monitor is malfunctioning.GWarning
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the inflation
pressure recommended by the vehicle
manufacturer on the Tire and Loading
Information placard on the driver’s door B-
pillar or the tire inflation pressure label on the
inside of the fuel filler flap. If your vehicle has
tires of a different size than the size indicated
on the Tire and Loading Information placard
or the tire inflation pressure label, you should
determine the proper tire inflation pressure
for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires are significantly underinflated.
Accordingly, when the low tire pressure
telltale 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 vehicle's
handling and stopping ability. Please note that
the TPMS is not a substitute for proper tire
maintenance, and it is the driver's
responsibility to maintain correct tire
pressure, even if underinflation has not
Tire pressure487Tires and wheelsZ

XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire Pressures
Displayed After Driving A Few
Minutes message appears in the display.
After a teach-in period, the tire pressure
monitor automatically recognizes new wheels
or new sensors. As long as a clear allocation
of the tire pressure values to the individual
wheels is not possible, the Tire Pressure
Monitor Active message is shown instead
of the tire pressure display. The tire pressures
are already being monitored.
i If a spare wheel/emergency spare wheel
is mounted, the system may continue to
show the tire pressure of the wheel that has
been removed for a few minutes. If this
occurs, note that the value displayed for
the position where the spare wheel is
mounted is not the same as the spare
wheel/emergency spare wheel's current
tire pressure.
TPMS warning messages
If the tire pressure monitor detects a
significant pressure loss on one or more tires,
a warning message is shown in the
multifunction display. A warning tone also
sounds and the tire pressure warning lamp
lights up in the instrument cluster.
For each tire that is affected by a significant
loss of pressure, the tire pressure is shown in
yellow.
If the Correct Tire Pressure message
appears in the multifunction display:
XCheck the tire pressure on all four wheels
and correct it if necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
short time. This is rectified after a few
minutes of driving, and the tire pressures
are displayed for the correct positions.
Restarting the tire pressure monitorGWarning
It is the driver's responsibility to set the tire
inflation pressure to the recommended cold
tire inflation pressure. Underinflated tires
affect the ability to steer or brake the vehicle.
You might lose control over the vehicle.
When you restart the tire pressure monitor,
all existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the
reference values for monitoring.
The TPMS must be restarted when you set the
tire pressure to a new value (as a result of
changed handling or load characteristics, for
example). The TPMS then monitors the new
tire pressure values.
i Canada only: in most cases, the tire
pressure monitor recognizes the new
reference values automatically. However,
you can also define reference values
manually as described here.
Restart the tire pressure monitor after you
have set the tire pressure to the value
recommended for the desired driving
situation ( Y page 483). Only correct tire
pressures on cold tires. Comply with the
recommended tire pressures on the Tire and
Loading Information placard on the B-pillar on
the driver's side Additional tire pressure
values for driving at high speeds or with heavy
loads can be found in the Tire Pressure table
on the inside of the fuel filler flap.
XMake sure that the tire pressure is correct
on all four wheels.XMake sure that the SmartKey is in position
2 in the ignition lock.XPress the = or ; button to select the
Service menu.Tire pressure489Tires and wheelsZ