2008 MERCEDES-BENZ R320 weight

393 Operation
Tires and wheels
Tire ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.
Warning!G
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underin-
flation, or excessive loading, either sepa-
rately or in combination, can cause
excessive heat build-up and possible tire
failure.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

394 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 certi-
fication 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.

395 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,
total load limit 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 square inch)
A standard unit of measure for air pressure
-> bar, kilopascal (kPa).
Recommended tire inflation pressure
Recommended tire inflation pressure for
normal driving conditions is listed on the
Tire and Loading Information placard
located on the driver’s door B-pillar.
Provides best handling, tread life and
riding comfort. If so equipped, supplemen-
tal information pertaining to special driving
situations can be found on the tire inflation
pressure label on the inside of the fuel filler
flap.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 (Tire Identification Number)
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.

396 Operation
Tires and wheels
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.
Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.
Traction
Force exerted by the vehicle on the road
via the tires. The amount of grip provided.
Tread
The portion of a tire that comes into
contact with the road.Treadwear indicators
Narrow bands, sometimes called
“wear bars” that show across the tread of
a tire when only
1/16in (1.6 mm) of tread
remains.
TWR (T
ongue Weight Rating)
Maximum permissible weight on trailer
tongue.
Uniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire’s traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The
ratings are molded into the sidewall of the
tire.
Vehicle maximum load on the tire
Load on an individual tire that is
determined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing it by two.
Rotating tires
Tire rotation can be performed on vehicles
with tires of the same dimension all
around. If your vehicle is equipped with
tires of the same dimension all around,
tires can be rotated, observing a
front-to-rear rotation pattern that will
maintain the intended rotation (spinning)
direction of the tire (
page 365).
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.
Warning!G
Rotate front and rear wheels only if the tires
are of the same dimension.
If your vehicle is equipped with mixed-size
tires (different tire dimensions front vs.
rear), tire rotation is not possible.

425 Practical hints
What to do if …
Lamp in center console
ProblemPossible cause/consequenceSuggested solution
59The front passenger
front air bag off indica-
tor lamp illuminates
and remains illuminat-
ed with the weight of a
typical adult or some-
one larger than a small
individual on the front
passenger seat.The system is malfunctioning.Have the system checked as soon as
possible by an authorized
Mercedes-Benz Light Truck Center.
Also read and observe any messages
in the multifunction display and follow
corrective steps (
page 438).
Warning!G
If the59indicator lamp
illuminates and remains illuminated with the
weight of a typical adult or someone larger
than a small individual on the front passen-
ger seat, do not have any passenger use the
front passenger seat until the system has
been repaired.

426 Practical hints
What to do if …
ProblemPossible
cause/consequenceSuggested solution
59The front passenger
front air bag off indica-
tor lamp does not illu-
minate and/or does
not remain illuminated
with the weight of a
typical 12-month-old
child in a standard
child restraint or less
on the front passenger
seat.The system is malfunction-
ing.Make sure there is nothing between seat cushion and
child seat and check installation of the child seat.
Make sure no objects applying supplemental weight
onto the seat are present.
Make sure no objects which apply forces to the seat
are present (e.g. objects such as books, briefcases
etc. lodged behind or around the seat, head restraints
pushing against roof etc.). The system may recognize
such forces as supplemental weight.
If the front passenger front air bag off indicator lamp
remains out, have the system checked as soon as pos-
sible by an authorized Mercedes-Benz Light Truck
Center. Do not transport a child on the front passen-
ger seat until the system has been repaired.
Also note any messages in the multifunction display
and follow corrective steps (
page 438).
Warning!G
If the59indicator lamp does
not illuminate or remains out with the
weight of a typical 12-month-old child in a
standard child restraint or less on the front
passenger seat, do not transport a child on the front passenger seat until the system
has been repaired.

438 Practical hints
What to do if …
Display messagePossible
cause/consequencePossible solution
Front Passenger Airbag
Enabled
See Operator’s ManualFront passenger front
air bag is activated
while driving even
though a child, small
individual, or object
below the system’s
weight threshold is on
the front passenger
seat, or the front pas-
senger seat is empty.
Objects on the seat or
forces acting on the
seat may make the
system sense supple-
mental weight.Stop the vehicle in a safe location as soon as possible and check the front passen-
ger seat for the following:
Apply the parking brake (page 65).
Switch off the ignition (page 39).
Remove child and child restraint from front passenger seat and properly secure
the child in rear seat employing the child restraint if necessary.
Remove any other items from on and around the front passenger seat and
make sure the storage bag on the back of the front passenger seat is empty.
Make sure that no objects which apply forces to the seat are present (e.g. ob-
jects such as books, briefcases etc. lodged behind or around the seat, head re-
straints pushing against roof etc.). The system may recognize such forces as
supplemental weight and sense that an occupant on the front passenger seat
is of a greater weight than actually present.
Keep the seat unoccupied, close the front passenger door and switch on the
ignition (
page 39).
(Continued on next page)

440 Practical hints
What to do if …
Display messagePossible
cause/consequencePossible solution
Front Passenger Airbag
Disabled
See Operator’s ManualFront passenger front
air bag is deactivated
while driving even
though an adult or
someone larger than a
small individual is oc-
cupying the front pas-
senger seat. Forces
acting on the seat may
make the system
sense a decrease in
weight.Stop the vehicle in a safe location as soon as possible and check the front
passenger seat for the following:
Apply the parking brake (page 65).
Switch off the ignition (page 39).
Have the front passenger vacate the seat and exit the vehicle.
Adjust the seat in a height position (page 44).
Make sure that no objects which apply forces to the seat are present (e.g. ob-
jects such as books, briefcases etc. lodged underneath, behind or around the
seat). Such forces may cause the system to sense that an occupant of a lesser
weight than actually present is on the front passenger seat.
Keep the seat unoccupied, close the front passenger door and switch on the
ignition (
page 39).
(Continued on next page)