2007 MERCEDES-BENZ GL450 off road

352 Operation
Driving instructions
Parking brake
When driving on wet roads or dirt covered
surfaces, road salt and/or dirt can get into
the parking brake. To prevent corrosion
and a reduction in the braking power of the
parking brake, observe the following:
From time to time, lightly engage the
parking brake before driving off.
Drive a distance of approximately
110 yds (100 m) at a maximum speed
of 12 mph (20 km/h).
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.Parking
Warning!G
While performing this procedure, please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle’s brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
!When driving off on a slippery surface, do
not allow a drive wheel to spin for an extended
period with the ESP
® switched off. Doing so may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.
!Simultaneously depressing the accelerator
pedal and applying the brake reduces engine
performance and causes premature brake and
drivetrain wear.
Warning!G
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
To reduce the risk of personal injury or
damage to the vehicle drivetrain as a result
of vehicle movement, before turning off the
engine and leaving the vehicle always:

Keep right foot on brake pedal.

Firmly depress parking brake pedal.

Set the automatic transmission to
positionP.

Slowly release brake pedal.

When parked on an incline, turn front
wheel towards the road curb.

355 Operation
Driving instructions
GL 320 CDI, GL 450
Your vehicle is factory equipped with
“H”-rated tires, which have a speed rating
of 130 mph (210 km/h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km/h).
GL 450*
Your vehicle is factory equipped with
“W”-rated tires, which have a speed rating
of 168 mph (270 km/h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km/h).Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
shift the automatic transmission to
positionN. Try to keep the vehicle under
control by corrective steering action.
Road salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.
iFor information on speed ratings for winter
tires, see “Winter tires” (
page 420).
For additional general information on tire speed
markings on the tire sidewall, see “Tire speed
rating” (
page 418).
iFor information on driving with snow chains,
see “Snow chains” (
page 421).
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle
steering is adversely affected by the
Off-road – ABS (
page 104).

357 Operation
Driving instructions
Off-road drivingRead this chapter carefully before you be-
gin off-road travel.
Familiarize yourself with the vehicle char-
acteristics and gear changing before you
attempt any difficult terrain off-road driv-
ing. We recommend that you start out with
easy off-road travel.
Warning!G
Do not load items on the basic cross bars*.
It may cause instability during some maneu-
vers which could result in an accident.
Drive slowly in unknown terrain. This will
make it easier to recognize unexpected ob-
stacles and avoid damage to the vehicle.
To help avoid the vehicle rolling over, never
turn it around on steep inclines. If the vehi-
cle cannot complete the attempted climb,
back it down in reverse gear.
Do not drive along the side of a slope. The
vehicle might otherwise rollover. If in doing
so the vehicle begins to show a tendency to
roll, immediately steer into a line of gravity
(straight up or downhill).
Never let the vehicle roll backwards in idle.
You may lose control of the vehicle if you
use only the service brake. For information
on driving downhill, see “Driving downhill”
(
page 361).
Warning!G
Sand, dirt, mud and other material having
friction property can cause exceptional wear
and tear as well as brake failure.
Have the brakes checked for dirt build-up
and cleaned. There is otherwise a risk that
full braking power may not be available in an
emergency.
Warning!G
Please be aware that by raising the vehicle
level, the center of gravity also rises. There-
fore, always ensure that the vehicle level is
as low as possible. With higher ride height
the ESP
® may activate earlier in certain
situations.

358 Operation
Driving instructions
Special driving features for off-road
driving
The following driving features are available
for specific kind of operation:

Off-road – ABS (page 104)

Off-road – ESP® (page 108)

Off-road – 4-ETS (page 110)

Hill start assist system (page 199)

LOW RANGE mode* (page 203)

Differential locks* (page 206)

Downhill Speed Regulation (DSR)
(
page 275)

Off-road driving program (Vehicles
without enhanced off-road package*)
(
page 279)

Air suspension (page 280)Off-road driving rules

Engage the off-road driving program
(
page 279) or LOW RANGE mode*
(
page 203) before driving under
off-road conditions.

If necessary, activate differential
locks* (
page 206).

Make sure you select a vehicle level
(
page 281) appropriate to the topo-
graphical conditions. Always make
sure the vehicle has enough ground
clearance.

Fasten items being carried as securely
as possible (
page 297).

Always navigate gradients with the en-
gine on and with the transmission en-
gaged in a gear. Switch on the DSR
(
page 276) to help maintain a preset
speed.
!Observe the following during off-road
driving:

Keep doors, tailgate, windows, and
tilt/sliding sunroof* closed whenever driving
off-road.

Adjust vehicle speed to condition of terrain.
The more uneven, rutty and steeper the ter-
rain, the lower the speed should be. Drive
through water slowly at an even speed,
avoiding a bow wave.

Be especially careful when driving in un-
known territory. It may be necessary to get
out of the vehicle and scout the path you in-
tend to take.

Watch out for obstacles, such as rocks,
holes, tree stumps and ruts.

Before driving through water, determine its
depth.

Do not stop vehicle while immersed in water,
and do not shut off the engine.

359 Operation
Driving instructions
Checklist before off-road driving
Engine oil level

Check the engine oil level with the oil
dipstick (
page 381).
Only with a proper oil level can the
vehicle obtain a trouble-free oil supply,
even on steep gradients.Tires

Check the tread depth and maintain
specified tire inflation pressure
(a placard with the recommended tire
inflation pressures is located on the
driver’s door B-pillar (
page 389)).

Check tires for possible damage and
remove foreign objects.

Replace missing valve caps.
Rims

Dented or bent rims can cause tire in-
flation pressure loss and damage the
tire beads. For this reason, check and,
if necessary, change rims before driv-
ing off-road.
Vehicle tool kit

Check if the vehicle jack (page 497)
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.

In sandy soil, drive at a steady speed as al-
lowed 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 onto slopes with the engine
running and the vehicle in gear.

Do not shift automatic transmission to
positionN.
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 396) before continuing
your trip. Driving with reduced tire inflation
pressure increases the risk of losing control
of the vehicle and rolling over.
!If the engine oil level warning lamp
(
page 476) comes on while driving, stop the
vehicle in a safe location or as soon at is safe to
do so. Check the engine oil level (
page 381).
The engine oil level warnings should not be
ignored. Extended driving with the symbol
displayed could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.

360 Operation
Driving instructions
Driving in steep terrain
Slope angle
1 Overhang angle, front
2Overhang angle, rear

Comply with the warnings
(
page 357) and rules for off-road
driving (
page 358).

Driving on embankments, slopes and
other steep inclines should only be
done straight up or downhill, i.e. in the
line of gravity. Maximum vehicle climb-
ing ability is a 100% grade which is
equivalent to a slope angle of
45 degrees. Keep in mind that the
climbing ability of the vehicle depends
on terrain conditions.

Shift automatic transmission to
position1 (
page 200).

Drive slowly.

Avoid excessive engine speeds – drive
with moderate engine speeds
(max. 3 000 rpm).

Utilize the engine’s braking power
when descending a slope, observe the
engine speed (do not overrev the en-
gine). Apply the service brake as need-
ed.

Check the brakes after a lengthy down-
grade drive.Vehicles with air
suspension pack-
age12
Raised level34°28°
Highway29°23°
Vehicles with
enhanced off-road
package*12
Off-road-level 336°30°
Off-road-level 234°28°
Off-road-level 131°25°
Highway29°23°
iFor maximum engine speed, see “Instru-
ment cluster” (
page 26) and see “Engine”
(
page 553).
Warning!G
Never turn the vehicle around on steep
inclines. The vehicle might roll over. If the
vehicle cannot complete the attempted
climb, back it down in reverse gear.

361 Operation
Driving instructions
Traction in steep terrain
The maximum vehicle climbing ability is a
100% grade which is equivalent to a slope
angle of 45 degrees. Keep in mind that the
climbing ability of the vehicle depends on
terrain conditions.
Be easy on the accelerator and watch for
continuous wheel traction when driving in
steep terrain.Driving across a hilltop
Decelerate just ahead of a hilltop (do not
shift automatic transmission to
positionN), to prevent the vehicle from
speeding up too much after climbing a hill.
Use the momentum of the vehicle to drive
across the hilltop.
After climbing a hill, driving in this manner
prevents the vehicle from:

losing ground contact when cresting
hills

losing its forward momentum

speeding up too much after climbing
the hillDriving downhill

Drive slowly.

Do not drive at an angle to the incline.
Steer into the line of gravity and drive
with the front wheels pointing straight
downhill. Otherwise, the vehicle may
slide sideways off the path and roll
over.

Shift automatic transmission to
position1 (
page 200).

On steep inclines, use the Downhill
Speed Regulation (
page 275).

Utilize the engine’s braking power to
reduce vehicle speed.
If this is insufficient, apply the brake
gently. Make sure the vehicle is moving
in the line of gravity.

Check the brakes after a lengthy down-
grade drive.
iThe hill start assist system supports you
when driving uphill.
For more information, see “Hill start assist sys-
tem” (
page 199).
iThe 4-ETS helps greatly when starting out on
a steep incline when the front wheels have then
the tendency to slip due to the weight shifting
towards the rear axle.
The 4-ETS recognizes the situation and limits the
torque for the front wheels by braking them.
Simultaneously the torque for the rear wheels is
increased.
iVehicles with enhanced off-road package*
are equipped with automatic locks for the center
and rear axle differential to improve vehicle
traction.

362 Operation
Driving instructions
Driving through water
1Fording depth

Before driving through water, deter-
mine its depth.

Select the highest vehicle level
possible (
page 281).

Switch to off-road driving program
(
page 279) or LOW RANGE mode*
(
page 203) before driving through
water.

Shift automatic transmission to
position1 or2 (
page 200).

Avoid high engine speeds.

Enter and leave the water only at a
shallow spot, driving at walking speed.

Drive through the water slowly and at a
constant speed.
iThe special Off-road – ABS (page 104)
setting allows for precise and brief (cyclical)
blocking of the front wheels, permitting them to
dig into loose ground.
Remember that, when stopped, the front wheels
slide across a surface and thus lose their ability
to steer the vehicle.Vehicles with air
suspension
package1
Raised level20.00in (50cm)
Vehicles with
enhanced off-road
package*1
Off-road 3 level23.60 in (60 cm)
Off-road 2 level20.00 in (50 cm)
Off-road 1 level20.00 in (50 cm)
!The water depth must not exceed the
respective value listed in the table. The ground
under the water might not be firm which could
result the water being deeper than expected
when driving the vehicle through it. Please note
that the water level is correspondingly lower for
flowing water.
!Never accelerate before driving into the
water. The bow wave could force water into the
engine and auxiliary equipment, thus damaging
them.