inflation pressure MERCEDES-BENZ R500 2006 W251 Owner's Guide

382 OperationTires and wheelsMaximum tire load
1Maximum tire load rating
The maximum tire load is the maximum
weight the tires are designed to support.For more information on tire load rating
(
page 377).
For information on calculating total and
cargo load capacities (
page 359).
Maximum tire inflation pressure
1Maximum permissible tire inflation
pressure
This is the maximum permissible tire
inflation pressure for the tire.
iFor illustration purposes only. Actual
data on tires are specific to each vehi-
cle and may vary from data shown in
above illustration.
Warning!
G
Do not overload the tires by exceeding the
specified load limit as indicated on the plac-
ard located on the driver’s door B-pillar.
Overloading the tires can overheat them,
possibly causing a blowout. Overloading the
tires can also result in handling or steering
problems, or brake failure.
iFor illustration purposes only. Actual
data on tires are specific to each vehi-
cle and may vary from data shown in
above illustration.

383 Operation
Tires and wheels
Always follow the recommended tire
inflation pressure (
page 363) for proper
tire inflation. Uniform Tire Quality Grading Standards
(U.S. vehicles)
Tire manufacturers are required to grade
tires based on three performance
factors: treadwear, traction and
temperature resistance.
1Treadwear
2Traction
3Temperature resistanceQuality grades can be found, where appli-
cable, on the tire sidewall between tread
shoulder and maximum section width. For
example:
All passenger car tires must conform to
federal safety requirements in addition to
these grades.
Warning!
G
Never exceed the max. tire inflation
pressure. Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adverse-
ly affect handling and fuel economy, and are
more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride com-
fort, wear unevenly, increase stopping dis-
tance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road de-
bris, potholes etc.
iFor illustration purposes only. Actual
data on tires are specific to each vehi-
cle and may vary from data shown in
above illustration.
Treadwear
Traction
Temperature
200
AA
A

386 OperationTires and wheelsBar
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 GWV must never exceed the
GWVR 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.

387 Operation
Tires and wheels
Maximum load rating
The maximum load in kilograms and
pounds that can be carried by the tire.
Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
vehicle capacity weight and production
options weight.
Maximum tire inflation pressure
This number is the greatest amount of air
pressure that should ever be put in the tire
under normal driving conditions.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by
68 kilograms (150 lbs).
Occupant distribution
The distribution of occupants in a vehicle
at their designated seating positions.Production options weight
The combined weight of those installed
regular production options weighing over
5 lbs (2.3 kilograms) in excess of those
standard items which they replace, not
previously considered in curb weight or
accessory weight, including heavy duty
brakes, ride levelers, roof rack, heavy duty
battery, and special trim.
PSI (P
ounds per s
quare i
nch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure
listed on placard located on driver’s door
B-pillar for normal driving conditions.
Provides best handling, tread life and
riding comfort.Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated.
Sidewall
The portion of a tire between the tread and
the bead.
TIN (T
ire I
dentification N
umber)
Unique identifier which facilitates efforts
by tire manufacturers to notify purchasers
in recall situations or other safety matters
concerning tires and gives purchases the
means to easily identify such tires. The TIN
is comprised of “Manufacturer’s identifica-
tion mark”, “Tire size”, “Tire type code”
and “Date of manufacture”.
Tire load rating
Numerical code associated with the
maximum load a tire can support.

389 Operation
Tires and wheels
In some cases, such as when your vehicle
is equipped with mixed-size tires (different
tire dimension front vs. rear), tire rotation
is not possible.
If applicable to your vehicle's tire configu-
ration, tires can be rotated according to
the tire manufacturer’s recommended in-
tervals in the tire manufacturer’s warranty
pamphlet located in your vehicle literature
portfolio. If none is available, tires should
be rotated every 3 000 to 6 000 miles
(5 000 to 10 000 km), or sooner if neces-
sary, according to the degree of tire wear.
The same rotation (spinning) direction
must be maintained (
page 356).
Rotate tires before the characteristic tire
wear pattern becomes visible (shoulder
wear on front tires and tread center wear
on rear tires).
Thoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.For information on wheel change, see “Flat
tire” (
page 478).
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
110 lb-ft (150 Nm).
Only use genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.

412 Practical hintsWhat to do if …Problem
Possible cause/consequence
Suggested solution
H
Combination low tire pres-
sure/TPMS malfunction telltale
for the TPMS or Advanced
TPMS* illuminates continuous-
ly.
The TPMS or Advanced TPMS* detects a
loss of pressure in at least one tire.

Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers. Observe the traffic situation
around you.

Read and observe messages in the
multifunction display.
If the tire inflation pressure in the respec-
tive tire(s) has (have) been corrected, the
combination low tire pressure/TPMS mal-
function telltale goes out after few minutes
driving.
H
Combination low tire pres-
sure/TPMS malfunction telltale
for the TPMS or Advanced
TPMS* flashes 60 seconds and
then stays illuminated.
There is a malfunction in the TPMS or
Advanced TPMS*.

Read and observe messages in the
multifunction display.

Have the TPMS or Advanced TPMS*
checked by an authorized
Mercedes-Benz Light Truck Center.
After the malfunction has been remedied,
the combination low tire pressure/TPMS
malfunction telltale goes out after few
minutes driving.

413 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
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.
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 under-inflation has not
reached the level to trigger illumination of
the TPMS low tire pressure telltale.
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 mal-
function 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.

427 Practical hints
What to do if …
Display message
Possible cause/consequence
Possible solution
Check tires
Then reactivate
Run Flat Indicator
There was a warning message about
a loss in the tire inflation pressure
and the Run Flat Indicator has not
been reactivated yet.

Make sure that the correct tire inflation pressure is set
for each tire.

Then reactivate the Run Flat Indicator.
Run Flat Indicator
inactive
Run Flat Indicator is malfunctioning.

Have the Run Flat Indicator checked by an authorized
Mercedes-Benz Light Truck Center.
Run Flat Indicator
unavailable
The Run Flat Indicator has been
switched off due to an error.

Have the Run Flat Indicator checked by an authorized
Mercedes-Benz Light Truck Center.
Tire pressure
Check tires
The Run Flat Indicator indicates that
the pressure is too low in one or more
tires.

Carefully bring the vehicle to a halt, avoiding abrupt
steering and braking maneuvers. Observe the traffic sit-
uation around you.

Check and adjust tire inflation pressure as required
(page 365).

If necessary, change the wheel (
page 478).

Reactivate the Run Flat Indicator after adjusting the tire
inflation pressure values (
page 365).

428 Practical hintsWhat to do if …Display message
Possible cause/consequence
Possible solution
Tire pressure displayed
only after driving
a few minutes
Vehicles with Advanced TPMS*:
The tire inflation pressure is being checked.

Drive the vehicle for a few minutes.
Tire pressure monitor
inoperative
The 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 sensors
There are wheels without 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
temporarily
unavailable
The TPMS or Advanced TPMS* is unable to
monitor the tire pressure due to

a nearby radio interference source


excessive wheel sensor temperatures

As soon as the causes for the malfunction are no
longer present, the TPMS or Advanced TPMS* auto-
matically becomes active again after a few minutes
of driving.
Tire pressure monitor
Wheel sensor missing
One or more sensors malfunction (e.g. bat-
tery in one or more wheel sensor is empty).
One or more wheels without wheel sensors
mounted (e.g. spare tire).

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.
Vehicles with Advanced TPMS*:
The tire pressure for the respective tire is shown in
the multifunction display.

448 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
H
Rectify
tire pressure
The pressure is too low in one or more
tires.

Check and correct tire inflation
pressure as required.
Tire pressure
Caution: Tire defect
One or more tires are deflating.

Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers.

If necessary, change the wheel.
Caution: Tire defect
Vehicles with Advanced TPMS*:
One or more tires are deflating.
The respective tire is shown in the
multifunction display.

Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers.

If necessary, change the wheel.
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 will cause excessive
heat build-up and possibly a fire.