251 Operation
Tires and wheels
Direction of rotation
Unidirectional tires offer added advan-
tages, 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 Certification label (Example B),
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 in-
cludes the weight of the vehicle, all oc-
cupants, 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 allow-
able weight that can be carried by a sin-
gle axle (front or rear). Never exceed
the GVWR or GAWR for either the front
axle or rear axle.
Depending on production date, some
vehicles may also be equipped with a
Tire and Loading Information placard
(Example A). This placard tells you
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 pres-
sures for the original equipment tires
on your vehicle.
1Driver’s door B-pillar
Following is a discussion on how to work
with the information contained on the two
placards with regards to loading your
vehicle.
iSpare wheels may be mounted against
the direction of rotation (spinning) even
with a unidirectional tire for temporary
use only until the regular drive wheel
has been repaired or replaced. Always
observe and follow applicable tempo-
rary use restrictions and speed limita-
tions indicated on the spare wheel.
253 Operation
Tires and wheels
Certification label (Example B)GVWR, GAWR on Certification label The Certification label showing the load
limit information is located on the driver’s
door B-pillar. Locate the heading GVWR
(Gross Vehicle Weight Rating) and GAWR
(Gross Axle Weight Rating) on this label.
The combined weight of the vehicle, all oc-
cupants, all cargo/luggage and trailer
tongue (if applicable) should never exceed
the GVWR and GAWR for the front or rear
axle listed on the Certification label.
To assure that your vehicle does not ex-
ceed the maximum permissible weight lim-
its (GVWR and GAWR for front and rear axle), have the loaded vehicle (including
driver, passengers and all cargo and, if ap-
plicable, trailer fully loaded) weighed on a
suitable commercial scale.
Seating capacity
The seating capacity gives you important
information on the number of occupants
that can be in the vehicle. Observe front
and rear seating capacity. Depending on
production date, your vehicle may be
equipped with placard Example A.
Your vehicle may not be equipped with
placard A nor other placard posting the
seating capacity. Legal requirements at
time of production of your vehicle did not
require manufacturers to post the seating
capacity.
Never let more people ride in the vehicle
than there are designated seating posi-
tions and seat belts available. Be sure ev-
eryone riding in the vehicle is correctly
restrained with a separate seat belt.
Placard (Example A)1Seating capacity
iData shown on placard examples are
for illustration purposes only. Seating
data are specific to each vehicle and
may vary from data shown in the illus-
tration below. Refer to placard on vehi-
cle for actual data specific to your
vehicle.
254 OperationTires and wheelsSteps for determining correct load limit
(only applicable to vehicles with placard
Example A)
The following steps have been developed
as required of all manufacturers under Title
49, Code of U.S. Federal Regulations, Part
575 pursuant to the “National Traffic and
Motor Vehicle Safety Act of 1966”.
Step 1 (Vehicles equipped with placard
Example A)
Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kg or XXX lbs.” on
your vehicle’s placard.
Step 2
Determine the combined weight of the
driver and passengers that will be
riding in your vehicle.Step 3
Subtract the combined weight of the
driver and passengers from XXX kilo-
grams or XXX lbs.
Step 4
The resulting figure equals the avail-
able amount of cargo and luggage load
capacity. For example, if the “XXX”
amount equals 1400 lbs and there will
be five 150 lbs passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs
(1400-750 (5 x150) = 650 lbs).
Step 5
Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely
exceed the available cargo and luggage
load capacity calculated in step 4.Step 6 (if applicable)
If your vehicle will be towing a trailer,
load from your trailer will be trans-
ferred to your vehicle. Consult this
manual to determine how this reduces
the available cargo and luggage load
capacity of your vehicle (
page 256).
The following table shows examples on
how to calculate total and cargo load
capacities with varying seating configura-
tions and number and size of occupants.
The following examples use a load limit
of 1500 lbs. This is for illustration
purposes only. Make sure you are using
the actual load limit for your vehicle stated
on the vehicle’s placard (
page 252).
255 Operation
Tires and wheels
The higher the weight of all occupants, the
less cargo and luggage load capacity is
available.
For more information, see “Trailer tongue
load” (
page 256).
Example
Combined
weight limit
of occu-
pants and
cargo from
placard
Number of
occupants
(driver and
passengers)
Seating
configura-
tion
Occupants weight
Combined
weight of all
occupants
Available cargo/luggage and trailer
tongue weight (total load limit from
placard minus combined weight of
all occupants)
1
1500 lbs
5
front: 2
rear: 3
Occupant 1: 150 lbs
Occupant 2: 180 lbs
Occupant 3: 160 lbs
Occupant 4: 140 lbs
Occupant 5: 120 lbs
750 lbs
1500 lbs - 750 lbs = 750 lbs
2
1500 lbs
3
front: 1
rear: 2
Occupant 1: 200 lbs
Occupant 2: 190 lbs
Occupant 3: 150 lbs
540 lbs
1500 lbs - 540 lbs = 960 lbs
3
1500 lbs
1
front: 1
Occupant 1: 150 lbs
150 lbs
1500 lbs - 150 lbs = 1350 lbs
256 OperationTires and wheelsCertification label
Even after careful determination of the
combined weight of all occupants, cargo
and the trailer tongue load (if applicable)
(page 256) as to not exceed the permis-
sible load limit, you must make sure that
your vehicle never exceeds the Gross
Vehicle Weight Rating (GVWR) and the
Gross Axle Weight Rating (GAWR) for ei-
ther the front or rear axle. You can obtain
the GVWR and GAWR from the
Certification label. The Certification Label
can be found on the driver’s door B-pillar
(page 251).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 256) must never exceed the
GVWR.
Gross Axle Weight Rating (GAWR): The
total allowable weight that can be carried
by a single axle (front or rear).
To assure that your vehicle does not ex-
ceed the maximum permissible weight
limits (GVWR and GAWR for front and rear
axle), have the loaded vehicle (including
driver, passengers and all cargo and, if ap-
plicable, trailer fully loaded) weighed on a
suitable commercial scale.Trailer tongue load
The tongue load of any trailer is an impor-
tant weight to measure because it affects
the load you can carry in your vehicle. If a
trailer is towed, the tongue load must be
added to the weight of all occupants riding
and any cargo you are carrying in the
vehicle. The tongue load typically is ten
percent of the trailer weight and every-
thing loaded in it.
If an approved Mercedes-Benz trailer hitch
is available for your G-Class vehicle model,
consult the instructions included in the
trailer hitch kit for vehicle towing capacity,
permissible gross trailer weight, trailer
tongue weight rating, and instructions on
loading and towing a trailer.
271 Operation
Tires and wheels
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.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 three hours or
driven no more than one 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.
272 OperationTires and wheelsGVW (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 one psi; another metric unit for
air pressure is bars. There are
100 kilopascals (kPa) to one bar.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, 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.
273 Operation
Tires and wheels
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.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.
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
1/16
in (1.6 mm) of tread
remains.
TWR (T
ongue W
eight R
ating)
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 capacity weight
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.