2007 MERCEDES-BENZ M-CLASS spare wheel

366 OperationTires and wheelsTire 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 pres-
sure” (
page 374).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:


excessive treadwear (
page 367)


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.
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368 OperationTires and wheelsDirection of rotation
Unidirectional tires offer added advantag-
es, such as better hydroplaning perfor-
mance. To benefit, however, you must
make sure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the
intended direction of rotation (spinning) of
the tire.
Loading the vehicle
Two labels on your vehicle show how much
weight it may properly carry.

The Tire and Loading Information
placard can be found on the driver’s
door B-pillar. This placard tells you im-
portant information about the number
of people that can be in the vehicle and
the total weight that can be carried in
the vehicle. It also contains information
on the proper size and recommended
tire inflation pressures for the original
equipment tires on your vehicle.


The certification label found on the
driver’s door B-pillar tells you about the
gross weight capacity of your vehicle,
called the Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight
of the vehicle, all occupants, fuel and
cargo. The certification label also tells
you about the front and rear axle
weight capacity, called the Gross Axle
Weight Rating (GAWR). The GAWR is
the total allowable weight that can be
carried by a single axle (front or rear).
Never exceed the GVWR or GAWR for
either the front axle or rear axle.
i
Spare wheels may be mounted against the
direction of rotation (spinning) even with a unidi-
rectional tire for temporary use only until the reg-
ular drive wheel has been repaired or replaced.
Always observe and follow applicable temporary
use restrictions and speed limitations indicated
on the spare wheel.
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377 Operation
Tires and wheels
Run Flat Indicator (Canada only)
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.
The Run Flat Indicator may function in a
restricted manner or with a delay

if snow chains are mounted to the
vehicle


in presence of ice and snow


if you are driving on a loose surface
(e.g. sand or gravel)


if you are driving in a very sporty man-
ner (involving rapid acceleration or high
speeds in curves)
Warning!
G
When the multifunction display shows the
message
Tire pressure Check tires
,
one or more of your tires is significantly un-
derinflated. You should stop and check your
tires as soon as possible, and inflate them to
the proper tire inflation pressure as indicat-
ed on the vehicle’s tire information placard.
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.
Each tire, including the spare, should be
checked monthly when cold and set to the
recommended tire inflation pressure as
specified on the Tire and Loading Informa-
tion placard (
page 369) or on the tire
inflation pressure label (
page 369).
Warning!
G
The Run Flat Indicator does not provide a
warning for wrongly selected tire inflation
pressures. Always adjust tire inflation pres-
sure according to the placard on the driver’s
door B-pillar or fuel filler flap.
The Run Flat Indicator does not replace reg-
ular checks of the tire inflation pressures
since a gradual pressure loss in all four tires
cannot be detected by the Run Flat
Indicator.
The Run Flat Indicator is not able to issue a
warning due to a sudden dramatic loss of
tire inflation pressure (e.g. tire blowout
caused by a foreign object). In this case
bring the vehicle to a halt by carefully apply-
ing the brakes and avoiding abrupt steering
maneuvers.
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379 Operation
Tires and wheels
Checking tire pressure electronically
with the Tire Pressure Monitoring
System (TPMS), (USA only)The TPMS only functions on wheels that
are equipped with the proper electronic
sensors. It monitors the tire inflation pres-
sure, as selected by the driver, in all four
tires. A warning is issued to alert you to a
decrease in pressure in one or more of the
tires.i
The
Tire
Pressure
Monitoring
System
(TPMS) is equipped with a combination low tire
pressure/TPMS malfunction telltale in the
instrument cluster (
page 27). Depending on
how the telltale illuminates, it indicates a low tire
pressure condition or a malfunction in the TPMS
system itself:


If the telltale illuminates continuously, one
or more of your tires is significantly underin-
flated. There is no malfunction in the TPMS.


If the telltale flashes for 60 seconds and
then stays illuminated, the TPMS system
itself is not operating properly.
Warning!
G
The TPMS does not indicate a warning for
wrongly selected inflation pressures. Always
adjust tire inflation pressure according to
the placard on the driver’s door B-pillar or, if
available, the supplemental tire pressure in-
formation on the inside of the fuel filler flap.
The TPMS is not able to issue a warning due
to a sudden dramatic loss of pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by care-
fully applying the brakes and avoiding
abrupt steering maneuvers.
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
vehicle placard or the tire inflation pressure
label. (If your vehicle has tires of a different
size than the size indicated on the vehicle
placard or the tire inflation pressure label,
you should determine the proper tire infla-
tion 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 to over-
heat and can lead to tire failure.

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382 OperationTires and wheels
Switch on the ignition (
page 40).

Press thej or kbutton on the
multifunction steering wheel until the
current inflation pressures for each tire
appear in the multifunction display.
i
When the message
Tire pressure
displayed after driving for a few
minutes
appears in the multifunction display,
the individual inflation pressure values are
matched with the tires. The individual values are
displayed after a few minutes driving.
Warning!
G
It is the driver’s responsibility to calibrate
the TPMS on the recommended cold infla-
tion pressure. Underinflated tires affect the
ability to steer or brake the vehicle. You
might lose control over the vehicle.
i
With a spare wheel without wheel sensor
mounted, the system may still indicate the tire
inflation pressure of the removed wheel for some
minutes. If this happens, keep in mind that the
indicated value where the spare wheel is mount-
ed does not reflect the actual spare tire inflation
pressure.Warning!
G
The TPMS does not indicate a warning for
wrongly selected inflation pressures. Always
adjust tire inflation pressure according to
the placard on the driver’s door B-pillar or, if
available, the supplemental tire pressure in-
formation on the inside of the fuel filler flap.
The TPMS is not able to issue a warning due
to a sudden dramatic loss of pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by care-
fully applying the brakes and avoiding
abrupt steering maneuvers.
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
vehicle placard or the tire inflation pressure
label. (If your vehicle has tires of a different
size than the size indicated on the vehicle
placard or the tire inflation pressure label,
you should determine the proper tire infla-
tion 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 are significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible. Driving on a signif-
icantly underinflated tire causes the tire to
overheat and can lead to tire failure.
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386 OperationTires and wheelsGeneral:
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 385) indicates
the nominal tire width in mm.
Aspect ratio
The aspect ratio2 (page 385) 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 385) 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 387).Rim diameter
The rim diameter4 (
page 385) 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 385) 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 391) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.
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395 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 (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
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 T
railer W
eight)
The GTW is the weight of the trailer plus
the weight of all cargo, equipment, luggage
etc. loaded on the trailer.GVW (G
ross V
ehicle W
eight)
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 V
ehicle W
eight R
ating)
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.
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400 OperationWinter drivingBlock heater (Canada only)
The engine is equipped with a block
heater.
The electrical cable may be installed at an
authorized Mercedes-Benz Light Truck
Center.
Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.Please observe the following guidelines
when using snow chains:


Use of snow chains is not permissible
with all wheel/tire combinations
(page 536).


Snow chains should only be used on
the rear wheels. Follow the manufac-
turer’s mounting instructions.


Only use snow chains that are
approved by Mercedes-Benz. Your
authorized Mercedes-Benz Light Truck
Center will be glad to advise you on this
subject.


Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.


Do not use snow chains on the spare
wheel (
page 538).
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.
!
Even on vehicles with all-wheel-drive use
snow chains on rear tires only.
Some tire sizes do not leave adequate clearance
for snow chains. To help avoid serious damage to
your vehicle or tires, use of snow chains is not
permissible with the spare wheel.
!
Vehicles with air suspension package*:
When driving with snow chains, do not select
SPORT mode (
page 269).
i
When driving with snow chains, you may
wish to deactivate the ESP
® (page 99) before
setting the vehicle in motion. This will improve
the vehicle’s traction.
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