249 Operation
Driving instructions
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
approximately
1/16in (1.6 mm), at which
point the tire is considered worn and
should be replaced.
The treadwear indicator appears as a solid
band across the tread.Specified tire inflation pressures must be
maintained. This applies particularly if the
tires are subjected to high loads (e.g. high
speeds, heavy loads, high ambient temper-
atures).
For more information, see “Tires and
wheels” (
page 277).
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.
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.
Warning!G
Although the applicable federal motor
vehicle safety laws consider a tire to be
worn when the treadwear indicators (TWI)
become visible at approximately
1/16in
(1.6 mm), we recommend that you do not
allow your tires to wear down to that level.
As tread depth approaches
1/8in (3.0 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.
Warning!G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
254 Operation
Driving instructions
Checklist before off-road driving
Engine oil level
Check the engine oil level with the
control system (
page 270). The
message
Engine oil level OK must
appear in the multifunction display.
Only then can the vehicle obtain a
trouble-free oil supply, even on steep
gradients.
!Observe the following during off-road
driving:
Keep doors, tailgate, windows, and
tilt/sliding sunroof closed.
Switch cruise control off.
Adjust vehicle speed to condition of terrain.
The more uneven, rutty, and steeper the
terrain, the lower the speed should be. Drive
through water slowly at an even speed,
avoiding a bow wave.
Be especially careful when driving in
unknown territory. It may be necessary to
get out of the vehicle and scout the path you
intend to take.
Watch out for obstacles, such as rocks,
holes, tree stumps, and ruts.
Avoid excessive engine speeds – drive at
moderate engine speeds (max. 3 000 rpm).
Before driving through water, determine its
depth.
Do not stop vehicle while immersed in water,
and do not shut off the engine.
In sandy soil, drive at a steady speed as
allowed by conditions. This helps overcome
the vehicle rolling resistance and reduces
the likelihood of the vehicle sinking into the
ground.
Do not initiate jumps with the vehicle. It
interrupts the forward momentum of the
vehicle.
Always drive on slopes with the engine
running and the vehicle in gear.
Inspect the vehicle for possible damage after
each off-road trip.
Warning!G
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure (
page 288) before continuing
your trip. Driving with reduced tire inflation
pressure increases the risk of losing control
of the vehicle and rolling over.
!If a engine oil level warning message
(
page 351) appears in the multifunction
display while driving, stop the vehicle in a safe
location or as soon at is safe to do so. Check the
engine oil level (
page 270).
The engine oil level warning messages should
not be ignored. Extended driving with the
message displayed could result in serious engine
damage that is not covered by the
Mercedes-Benz Limited Warranty.
255 Operation
Driving instructions
Tires
Check the tread depth and maintain
specified tire inflation pressure (the
Tire and Loading Information placard
with the recommended tire inflation
pressures is located on the driver’s
door B-pillar (
page 280)).
Check tires for possible damage and
remove foreign objects.
Replace missing valve caps.Rims
Dented or bent rims can cause tire
inflation pressure loss and damage the
tire beads. For this reason, check and,
if necessary, change rims before
driving off-road.
Vehicle tool kit
Check if the vehicle jack (page 367)
is functional.
In all cases take the vehicle tool kit,
a strong tow rope, a shovel, and a small
plank (to put under the vehicle jack on
sandy soil) with you.Driving in steep terrainSlope angle
1Overhang angle, front, 37°
2Overhang angle, rear, 31°
Comply with the warnings
(
page 253) and rules for off-road
driving (
page 253).
258 Operation
Driving instructions
Comply with the warnings
(
page 253) and rules for off-road
driving (
page 253).
Switch off the exterior lamps as well as
the climate control.
Select gear range2 or1 on the auto-
matic transmission (
page 167).
Enter and leave the water only at a
shallow spot, driving at walking speed.
Drive through the water slowly and at a
constant speed.
Do not stop vehicle while immersed in
water, and do not shut off the engine.
There is a very high level of driving
resistance in water. The surface is
slippery and may not be firm, making
pulling away in water difficult and
dangerous.
Make sure that only small bow waves
are formed when driving the vehicle
through water.
Clean mud off the tire tread after
driving through water.
To dry the brakes, apply pressure to the
brake pedal several times after leaving
the water.Crossing obstacles
!Never accelerate before driving into the
water. The bow wave could force water into the
engine and auxiliary equipment, thus damaging
them.
!Do not open any of the vehicle’s doors while
driving through water. Water could otherwise en-
ter the vehicle interior and damage the vehicle’s
electronics, as well as the interior equipment.
!Obstacles can damage the vehicle
underbody or suspension components. If possi-
ble, use the assistance of a second person out-
side the vehicle to scout the path you intend to
take and check for adequate ground clearance
when you cross obstacles with your vehicle. The
person assisting you outside the vehicle should
always be a safe distance away from the vehicle
and positioned so that he or she cannot get hurt
in case of any unexpected vehicle movement.
After off-road driving or crossing obstacles,
inspect vehicle for any damage, especially
vehicle underbody and suspension components.
Failure to do so can adversely affect the vehi-
cle’s future performance, including increased
chance of an accident.
259 Operation
Driving instructions
When driving over tree stumps, big rocks
and other obstacles, observe the following
rules:
Check the vehicle clearance before
crossing obstacles.
Comply with the warnings
(
page 253) and rules for off-road
driving (
page 253).
Select gear range1 on the automatic
transmission (
page 167).
Cross obstacles very slowly by aiming
one of the front wheels at the center of
the obstacle, and repeat same with the
rear wheel.Driving on sand
When driving on sand, observe the
following rules:
Avoid high engine speeds.
Shift automatic transmission into a
gear range that is appropriate for the
terrain.
In sandy soil, drive at a steady speed as
conditions permit. This helps overcome
the vehicle rolling resistance and
reduce the likelihood of the vehicle
sinking into the ground.
Drive in tracks of other vehicles if they
are not too deep and you have suffi-
cient clearance.
Ruts
A number of off-road tracks or other
byways have deep ruts which can cause
the underbody to come in contact with the
ground.
!Special attention is needed when you cross
obstacles on a steep incline.
The vehicle could slide sideways as a result of its
possible slanted position which in turn may
result in the vehicle tipping or rolling over.
Warning!G
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure (
page 288) before continuing
your trip. Driving with reduced tire inflation
pressure increases the risk of losing control
of the vehicle and rolling over.
!Check that the ruts are not too deep and
your vehicle’s clearance is sufficient. Otherwise:
your vehicle may be damaged
the underbody of the vehicle may come in
contact with the ground and you may get
stuck
266 Operation
At the gas station
G55AMG
1Coolant
2Brake fluidBrake fluid
Coolant
For normal replenishing, use water
(potable water quality).
For more information, see “Coolant level”
(
page 274) and see “Fuels, coolants, lu-
bricants, etc.” (
page 422).Engine oil level
For more information on engine oil, see
“Engine oil” (
page 269).
Windshield/rear window washer sys-
tem and headlamp cleaning system
For more information on refilling the
washer reservoir, see “Windshield/rear
window washer system and headlamp
cleaning system” (
page 275).
Vehicle lighting
Check function and cleanliness.
For information on replacing light bulbs,
see “Replacing bulbs” (
page 377).
For more information, see “Exterior lamp
switch” (
page 117).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 288).
!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. Notify an
authorized Mercedes-Benz Light Truck Center
immediately. Do not add brake fluid as this will
not solve the problem.
For more information, see “Practical hints”
(
page 326) and see “Brake fluid”
(
page 425).
277 Operation
Tires and wheels
Tires and wheels
Contact an authorized Mercedes-Benz
Light Truck Center for information on test-
ed 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 fur-
ther 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.
278 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 pressure”
(
page 286).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:
excessive treadwear (page 279)
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.