2008 MERCEDES-BENZ ML350 Spare wheel tire pressure

371 Operation
Tires and wheels
General:
Depending on the design standards used,
the tire size molded into the sidewall may
have no letter or a letter preceding the tire
size designation.
No letter preceding the size designation
(as illustrated above): Passenger car tire
based on European design standards.
Letter “P” preceding the size designation:
Passenger car tire based on U.S. design
standards.
Letter “LT” preceding the size designation:
Light Truck tire based on U.S. design
standards.
Letter “T” preceding the size designation:
Temporary spare tires which are high
pressure compact spares designed for
temporary emergency use only.Tire width
The tire width1 (
page 370) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (
page 370) is the
dimensional relationship between tire
section height and section width and is
expressed in percentage. The aspect ratio
is arrived at by dividing section height by
section width.
Tire code
The tire code3 (
page 370) indicates
the tire construction type. The “R” stands
for radial tire type. Letter “D” means diag-
onal or bias ply construction; letter “B”
means belted-bias ply construction.
At the tire manufacturer’s option, any tire
with a speed capability above 149 mph
(240 km/h) can include a “ZR” in the size
designation (for example: 245/40 ZR 18).
For additional information, see “Tire speed
rating” (
page 372).Rim diameter
The rim diameter4 (
page 370) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (
page 370) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 376) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.

380 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.
GTW (G
ross Trailer Weight)
The GTW is the weight of the trailer plus
the weight of all cargo, equipment, luggage
etc. loaded on the trailer.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.

409 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 or, if available, the tire
inflation pressure label on 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, if available,
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 monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly underinflated tire causes the tire too over-
heat 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 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the
malfunction exists. When the malfunction
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 in-
compatible 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.

426 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Tire Pressure Monitor
InoperativeThe TPMS or Advanced TPMS* is
malfunctioning.Have the TPMS or Advanced TPMS* checked by an
authorized Mercedes-Benz Light Truck Center.
Tire Pressure Monitor
Inoperative
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 Light Truck Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Light Truck Center.
Tire Pressure Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more sensors are defect (e.g.
battery is empty).
The respective tire is indicated by
- - -
instead of the tire inflation pressure in the
multifunction display.
Have the Advanced TPMS* checked by an autho-
rized Mercedes-Benz Light Truck Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Light Truck Center.
Vehicles with Advanced TPMS*:
One or more wheels without appropriate
wheel sensors mounted (e.g. spare tire).
The respective tire is indicated by
- - -
instead of the tire inflation pressure in the
multifunction display.
Have the Advanced TPMS* checked by an autho-
rized Mercedes-Benz Light Truck Center.
Have the wheel sensors installed by an authorized
Mercedes-Benz Light Truck Center.
Tire Pressure Monitor
Currently UnavailableThe TPMS or Advanced TPMS* is unable to
monitor the tire pressure due to a nearby
radio interference source.As soon as the causes of the malfunction have been
removed, the TPMS or Advanced TPMS* automati-
cally becomes active again after a few minutes
driving.

452 Practical hints
Where will I find ...?
Setting up the collapsible wheel chock
The collapsible wheel chock serves to ad-
ditionally secure the vehicle, e.g. while
changing the wheel.
1Tilt the plate upward
2Fold the lower plate outward
3Insert the plateTilt both plates upward1.
Fold the lower plate outward2.
Guide the tabs of the lower plate all the
way into the openings of base plate3.
For information on where to place wheel
chocks when changing a wheel, see “Lift-
ing the vehicle” (
page 479).
Minispare wheel (except ML 63 AMG)
Warning!G
The dimensions of the Minispare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a Minispare wheel
mounted. Adapt your driving style accord-
ingly.
The Minispare wheel is for temporary use
only. When driving with a Minispare wheel
mounted, ensure proper tire inflation
pressure and do not exceed a vehicle speed
of 50 mph (80 km/h).
Drive to the nearest Mercedes-Benz Light
Truck Center as soon as possible to have the
Minispare wheel replaced with a regular
road wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® when a
Minispare wheel is mounted.

453 Practical hints
Where will I find ...?
The Minispare wheel is located underneath
the cargo compartment floor
(
page 448).
Removing Minispare wheel
1Retaining screw
2Storage well casing
3Minispare wheelFor access the Minispare wheel, see “Vehi-
cle tool kit” (
page 448).
Loosen retaining screw1 by turning it
counterclockwise.
Remove storage well casing2.
Remove Minispare wheel3.
Collapsible tire (ML 63 AMG only)
iFor information on how to mount the
Minispare wheel, see “Mounting the spare
wheel” (
page 479).
iRemove Minispare wheel to gain access to
remaining tools in the vehicle tool kit
(
page 448).
Warning!G
The dimensions of the collapsible tire are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a collapsible tire
mounted. Adapt your driving style accord-
ingly.
The collapsible tire is for temporary use
only. When driving with a collapsible tire
mounted, ensure proper tire inflation
pressure and do not exceed a vehicle speed
of 50 mph (80 km/h).
Drive to the nearest Mercedes-Benz Light
Truck Center as soon as possible to have the
collapsible tire replaced with a regular road
wheel.
Never operate the vehicle with more than
one collapsible tire mounted.
Do not switch off the ESP
® when a
collapsible tire is mounted.

478 Practical hints
Flat tire
Preparing the vehicle
Vehicles with air suspension program*:
Make sure the vehicle level is set to
highway (
page 257).
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flasher
(
page 141).
Turn the steering wheel so that the
front wheels are in a straight-ahead
position.
Set the parking brake (page 57).
Set the automatic transmission to park
positionP (
page 185).
Turn off the engine (page 39).
Have any passenger exit the vehicle at
a safe distance from the roadway.
Vehicles with SmartKey: Remove the
SmartKey from the starter switch.
Vehicles with KEYLESS-GO*: Open the
driver’s door (this puts the starter
switch in position0, same as with the
SmartKey removed from the starter
switch). The driver’s door then can be
closed again.
Remove the KEYLESS-GO*
start/stop button from the starter
switch.
Warning!G
The dimensions of the spare wheel
(Minispare wheel or collapsible tire) are dif-
ferent from those of the road wheels. As a
result, the vehicle handling characteristics
change when driving with a spare wheel
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with a spare wheel mounted,
ensure proper tire pressure and do not ex-
ceed a vehicle speed of 50 mph (80 km/h).
Drive to the nearest Mercedes-Benz Light
Truck Center as soon as possible to have the
spare wheel replaced with a regular road
wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® when a
Minispare wheel is mounted.
Warning!G
Vehicles with air suspension program*:
Do not open or close any doors or the
tailgate while mounting a spare wheel. The
vehicle could rise or lower to a previously
selected level. You or others could be
injured as a result.
iOpen door only when conditions are safe to
do so.

486 Practical hints
Flat tire
Inflate the collapsible tire to the recom-
mended tire inflation pressure given in
the “Technical data” section
(
page 515).
This takes about 5 minutes for the col-
lapsible tire.
Press 0 on electric air pump switch2.
Turn the SmartKey in the starter switch
to position0.
or
Vehicles with KEYLESS-GO*:
Press the KEYLESS-GO start/stop
button twice without depressing the
brake pedal.
If the tire inflation pressure is above
the recommended tire inflation pres-
sure given in this Operator’s Manual,
release excess tire inflation pressure
using the vent screw.
Detach the electric air pump.
Store the electrical plug and the air
hose behind the flap and place the
electric air pump back in the cargo
compartment.
Warning!G
Air hose4 and union nut5 can become
hot during inflation. Exercise proper caution
to avoid burning yourself when using the
equipment.
!Do not operate the electric air pump longer
than 8 minutes without interruption. Otherwise it
may overheat.
You may operate the electric air pump again
after it has cooled off.
!Please compare the recommended tire
inflation pressure for your vehicle with the tire
inflation pressure on the yellow label located on
the spare wheel rim.
If the tire inflation pressure on the yellow label
on the spare wheel rim differs from the values
given in this Operator’s Manual, inflate the tire to
the recommended tire inflation pressure given
on the yellow label on the spare wheel rim.Warning!G
Follow recommend inflation pressures.
Do not overinflate tires. Overinflated tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.