2008 MERCEDES-BENZ R350 suspension

257 Controls in detail
Driving systems
Driving systems
The driving systems of your vehicle are
described on the following pages:

Cruise control (page 257) and
Distronic* (
page 262), with which
the vehicle can maintain a preset
speed.

Distance warning function*
(
page 275) is only available with
Distronic*, which warns of stationary
obstacles or slower moving vehicles
that you are closing in on too quickly.

AIRMATIC* (page 276) adjusts the
vehicle suspension characteristics
automatically and controls the vehicle
level.

Parktronic* (page 281) and rear view
camera* (
page 285), which serve as
a parking aid.
For information on the ABS, BAS, EBP,
ESP
®, and 4-ETS, see “Driving safety sys-
tems” (
page 99).
Cruise control
The cruise control automatically maintains
the speed you set for your vehicle.
The use of cruise control is recommended
for driving at a constant speed for extend-
ed periods of time. You can set or resume
cruise control at any speed above
20 mph (30 km/h).
The cruise control function is operated by
means of the cruise control lever.
The cruise control lever is the uppermost
lever on the left-hand side of the steering
column (
page 24).
Warning!G
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always
remain responsible for the vehicle’s speed
and for safe brake operation.
Only use the cruise control if the road, traffic
and weather conditions make it advisable to
travel at a constant speed.

The use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow
safe driving at a constant speed.

The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in
wheel spin and loss of control.

Deactivate the cruise control when
driving in fog.
The “Resume” function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.

276 Controls in detail
Driving systems
Switch on the distance warning func-
tion in the control system
(
page 185).1Symbol for activated distance warning
function
When the distance warning function is
switched on, you will see the: symbol
in the Standard display. When the
distance warning function is deactivated
the:symbol will not appear.
AIRMATIC*
The AIRMATIC* consists of two compo-
nents:

Adaptive Damping System (ADS)*
(
page 276): Automatically optimizes
your vehicle’s suspension tuning.

Vehicle level control* (page 277):
Regulates the ride height of the vehicle.
Adaptive Damping System (ADS)*
The fine tuning of the damping is depen-
dent on:

road surface conditions

your driving style

your personal settings
The ADS switch is located on the upper
part of the center console.
Warning!G
If the distance warning lampl in the in-
strument cluster comes on while driving
and/or an intermittent warning sounds,
immediate attention on the part of the driver
is required. As required by the traffic
situation, apply the brakes and navigate
around a possible obstacle. However, do not
drive by relying on the distance warning
function, as this will result in an emergency
braking application. This will not always
enable you to avoid a collision, especially
when traveling on varying road surface
conditions and with varying driver reaction.
Complex driving situations are not always
fully recognized by the distance warning
function. This could result in wrong or miss-
ing distance warnings.

277 Controls in detail
Driving systems
1ADS switch
2Indicator lamp for SPORT setting
3Indicator lamp for COMF settingThe following settings are available:

AUTO (for normal driving situations)
Indicator lamps2 and3 are off.

SPORT (for sporty driving)
Indicator lamp2 comes on.

COMF (for comfort driving)
Indicator lamp3 comes on.
Start the engine (page 53).
Press ADS switch1 repeatedly until
the desired suspension tuning is
reached.Vehicle level control*
The vehicle level control automatically
regulates the ride height to

reduce fuel consumption

improve driving safety
The vehicle begins adjusting to the set
vehicle level as soon as the doors or
tailgate are

unlocked
or

opened or closed with the vehicle
unlocked
For major changes in vehicle level, the
engine must be running.
iThe setting is stored when you turn off the
engine.
iChanges to the vehicle level should be made
while the vehicle is moving. The vehicle will then
reach the set level as fast as possible.

278 Controls in detail
Driving systems
Basic settings
There are two settings from which to
choose:

Raised level, for driving on rough roads

Highway level, for driving on paved
roads in fair or better conditionThe vehicle’s ride height changes by the
approximate values given in table below
according to the set level:
The vehicle lowers to highspeed level
automatically when

the vehicles speed exceeds
70 mph (112 km/h)

the vehicles speed is between
60 mph (96 km/h) and
70 mph (112 km/h) for longer
than 20 seconds
Warning!G
Make sure that no one is near the wheel
housing or under the vehicle when you lower
the vehicle while it is standing still. Limbs
could become wedged into or under the
vehicle.
For safety reasons, the vehicle can only be
lowered with all doors and the tailgate
closed. Lowering is interrupted if a door or
the tailgate is opened and will continue after
the door is closed again.
Warning!G
Adapt your speed and driving to possible
changed driving behavior of the vehicle after
changing the vehicle level. The ESP
® cannot
prevent accidents, including those resulting
from excessive speed. The ESP
® cannot
prevent the natural laws of physics from
acting on the vehicle.
!Keep in mind that in rough or uneven roads,
adjusting the vehicle to a lower level may cause
the vehicle underbody to come in contact with
the road and result in damage to the vehicle un-
derbody. Always make sure the vehicle has suffi-
cient ground clearance before adjusting it to a
lower level.
!Before jacking up the vehicle with equip-
ment that lifts one or more of the wheels com-
pletely off the ground, remove the SmartKey
from the starter switch.
!Please also note the information in the
section on towing (
page 513).
iThe activation threshold is defined by the set
suspension tuning (
page 276).
iThe third available level is the highspeed
level that is set automatically.
LevelRide height
Raised+ 1.97 in (+ 50 mm)
Highway+/- 0
Highspeed- 0.78 in (- 20 mm)
iObey local speed limits. Use prudent driving
speeds appropriate to prevailing conditions.

363 Operation
Tires and wheels
Tires and wheels
Contact an authorized Mercedes-Benz
Light Truck 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 Light Truck Center for
further information. 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
retreads. The operating safety of the vehicle
cannot be assured when such tires are used.

513 Practical hints
Towing the vehicle
Towing the vehicle
Mercedes-Benz recommends that the
vehicle be transported with all wheels off
the ground using flatbed or appropriate
wheel lift/dolly equipment. This method is
preferable to other types of towing.If circumstances do not permit the recom-
mended towing methods, the vehicle may
be towed with all wheels on the ground
only so far as necessary to have the vehicle
moved to a safe location where the recom-
mended towing methods can be employed.
When towing the vehicle with all wheels on
the ground, the vehicle may be towed only
for distances up to 30 miles (50 km) and at
a speed not to exceed 30 mph (50 km/h).
!Do not tow-start the vehicle.
!Use flatbed or wheel lift/dolly equipment,
with the SmartKey in starter switch turned to
position0.
Do not tow with sling-type equipment. Towing
with sling-type equipment over bumpy roads will
damage radiator and supports.
To prevent damage during transport, do not tie
down vehicle by its chassis or suspension parts.
Use the towing eyes.
Switch off the ESP
® (page 104) and the
automatic central locking (
page 126).
!Do not tow with one axle raised. Doing so
could damage the transfer case, which is not
covered by the Mercedes-Benz Limited
Warranty.
All wheels must be on or off the ground. Observe
instructions for towing the vehicles with all
wheels on the ground.
Warning!G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if

the engine will not run

there is a malfunction in the brake
system

there is a malfunction in the power
supply or in the vehicle’s electrical
system
as that will be necessary to adequately
control the vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the automatic trans-
mission is in neutral positionN.

515 Practical hints
Towing the vehicle
Remove the KEYLESS-GO* start/stop
button from the starter switch
(
page 41).
Insert the SmartKey with
KEYLESS-GO* into the starter switch.
Switch on the ignition.
Depress the brake pedal.
Shift the automatic transmission to
neutral positionN.
Release the brake pedal.
If engaged, release the parking brake
(
page 56).
Switch off the ignition and leave the
SmartKey with KEYLESS-GO* in the
starter switch.
Installing towing eye bolt
Depending on whether you are towing a
vehicle or you are being towed, the towing
eye bolt can be screwed into threaded
holes which are located behind covers on
the right-hand side of each bumper.
Example illustration R 550 4MATIC
1Towing eye cover
!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach a tow cable, tow rope or tow rod to
the vehicle chassis, frame or suspension parts.
iTo signal turns while being towed with
hazard warning flasher in use, set the starter
switch to position2 and activate combination
switch for left or right turn signal in usual manner
– only the selected turn signal will operate.
Upon canceling the turn signal, the hazard warn-
ing flasher will operate again.