2010 MERCEDES-BENZ R320 tire size

punctured or damaged by road debris,
potholes etc.
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
This is the maximum permissible tire inflation
pressure : for the tire.
Always follow the recommended tire inflation
pressure ( Y page 228) for proper tire
inflation. Loading the vehicle
Two labels on your vehicle show how much
weight it may properly carry.
(1) The Tire and Loading Information placard can be found on the driver’s door
B-pillar. This placard tells you important
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.
(2) The certification label, also found on the driver’s door B-pillar. It 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.
:
Driver’s door B-pillar
Following is a discussion on how to work with
the information contained on the Tire and
Loading Information placard with regards to
loading your vehicle.
Tire and Loading Information G
Warning!
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard 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. 236
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X
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.
X Step 6 (if applicable): If your vehicle will
be towing a trailer, load from your trailer
will be transferred to your vehicle. Consult
this

manual to determine how this reduces
the available cargo and luggage load
capacity of your vehicle ( Y page 240).
The following table shows examples on how
to calculate total and cargo load capacities
with varying seating configurations and
number and size of occupants. The following
examples use a load limit of 1 500 lbs. This
is

for illustration purposes only. Make sure
you are using the actual load limit for your
vehicle stated on the vehicle’s Tire and
Loading Information placard ( Y page 237).238
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tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire’s ability to stop on wet pavement as
measured under controlled conditions on
specified
government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance. G
Warning!
If ice has formed on the road, tire traction will
be
substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperature is close to the freezing point.
Mercedes-Benz recommends winter tires
(Y page 251) with a minimum tread depth of
approximately 1
/ 6 in (4 mm) on all four wheels
for the winter season to ensure normal
balanced handling characteristics. On
packed snow, they can reduce your stopping
distance compared to summer tires.
Stopping distance, however, is still
considerably greater than when the road is
not covered with snow or ice. Exercise
appropriate caution.
! Avoid spinning of a drive wheel. This may
cause serious damage to the drivetrain
which is not covered by the Mercedes-Benz
Limited Warranty.
Temperature G
Warning!
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B,

and C, representing the tire’s resistance to
the generation of heat and its ability to
dissipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive
temperature can lead to sudden tire failure.
The grade C corresponds to a level of
performance which all passenger car tires
must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on the
laboratory test wheel than the minimum
required by law. Rotating tires
G
Warning!
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. G
Warning!
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
110 lb-ft

(150 Nm).
Only use genuine Mercedes-Benz wheel bolts
specified for your vehicle’s rims.
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
(Y page 240).
In some cases, such as when your vehicle is
equipped with mixed-size tires (different tire Tires and wheels
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dimension front vs. rear), tire rotation is not
possible.
If applicable to your vehicle’s tire
configuration, tires can be rotated according
to the tire manufacturer’s recommended
intervals 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 necessary, according
to the degree of tire wear. The same rotation
(spinning) direction must be maintained.
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” ( Y page 319). Tire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
Following are some explanations for the
markings on your vehicle’s tires: :
Uniform Tire Quality Grading Standards
(Y page 242)
; DOT, Tire Identification Number
(Y page 247)
= Maximum tire load ( Y page 240)
? Maximum tire inflation pressure
(Y page 235)
A Manufacturer
B Tire ply material ( Y page 248)
C Tire size designation, load and speed
rating (Y page 245)
D Load identification ( Y page 247)
E Tire name
i For illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
For more information, see “Rims and tires”
(Y page 347). 244
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Tire size designation, load and speed
rating
:
Tire width
; Aspect ratio in %
= Radial tire code
? Rim diameter
A Load index
B Speed symbol
i For illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
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
Tire width : indicates the nominal tire width
in millimeters. Aspect ratio
Aspect ratio
; 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
Tire code = indicates the tire construction
type. The “R” stands for radial tire type. Letter
“D” means diagonal 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” (Y page 246).
Rim diameter
Rim diameter ? is the diameter of the bead
seat, not the diameter of the rim edge. The
rim diameter is indicated in inches (in).
Load index G
Warning!
The tire load rating must always be at least
half of the GAWR of your vehicle. Otherwise,
tire failure may be the result which may cause
an accident and/or serious injury to you or
others.
Always replace rims and tires with the same
designation, manufacturer and type as shown
on the original part. G
Warning!
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard 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.
Load index A is a numerical code associated
with the maximum load a tire can support. Tires and wheels
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For example, a load rating of 91 corresponds
to a maximum load of 1356 lb (615 kg) the
tire is designed to support. See also
“Maximum
tire load” (Y page 240) where the
maximum load associated with the load index
is indicated in kilograms and lbs.
For additional information on the load index,
see “Load identification” (Y page 247).
Speed symbol G
Warning!
Even when permitted by law, never operate a
vehicle at speeds greater than the maximum
speed rating of the tires.
Exceeding

the maximum speed for which tires
are rated can lead to sudden tire failure,
causing loss of vehicle control and possibly
resulting in an accident and/or serious
personal injury and possible death, for you
and for others.
Regardless of the tire speed rating, local
speed limits should be obeyed. Use prudent
driving speeds appropriate to prevailing
conditions.
Speed symbol B indicates the approved
maximum speed (tire speed rating) for the
tire.
Summer tires Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)
S up to 112 mph (180 km/h)
T up to 118 mph (190 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
ZR...Y up to 186 mph (300 km/h) Index Speed rating
ZR...(..Y) above 186 mph (300 km/h)
ZR above 149 mph (240 km/h)
R
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 ZR18).
To determine the maximum speed
capability of the tire, the service
description

for the tire must be referred to.
The service description is comprised of
load index A and speed symbol B.
If your tire includes “ZR” in the size
designation and no service description is
given, the tire manufacturer must be
consulted for the maximum speed
capability.
If a service description is given, the speed
capability is limited by the speed symbol in
the service description. Example:
245/40 ZR18 97Y. In this example, “97Y”
is the service description. The letter “Y”
designates the speed rating and the speed
capability of the tire is limited to 186 mph
(300 km/h).
R Any tire with a speed capability above
186 mph (300 km/h) must include a “ZR”
in the size designation AND the service
description must be placed in parenthesis.
Example: 275/40 ZR 18 (99Y). The “(Y)”
speed symbol in parenthesis designates
the maximum speed capability of the tire
as being above 186 mph (300 km/h).
Consult the tire manufacturer for the actual
maximum permissible speed of the tire.
All-season and winter tires Index Speed rating
Q M+S
14 up to 100 mph (160 km/h)
T M+S
14 up to 118 mph (190 km/h)
14
or M+S ifor winter tires 246
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The TIN is a unique identifier. The TIN
facilitates efforts by tire manufactures to
notify purchasers in recall situations or other
safety matters concerning tires. It gives
purchasers the means to easily identify such
tires.
The TIN is comprised of “Manufacturer’s
identification mark” ;, “Tire size”
=, “Tire
type code” ? and “Date of manufacture”
A.
i For illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
DOT (Department of Transportation) Tire branding symbol
: denotes that the tire
meets requirements of the U.S. Department
of Transportation.
Manufacturer’s identification mark Manufacturer’s identification mark ;
denotes the tire manufacturer.
New tires have a mark with two symbols.
Retreaded tires have a mark with four
symbols. For more information on retreaded
tires, see (
Y page 227).
Tire size Code
= indicates the tire size. Tire type code Tire type code
? may, at the option of the
manufacturer, be used as a descriptive code
for identifying significant characteristics of
the tire.
Date of manufacture The date of manufacture
A identifies the
week and year of manufacture.
The first two figures identify the week,
starting with “01” to represent the first full
week of the calendar year. The second two
figures represent the year.
For example, “3208” represents the 32nd
week of 2008. Tire ply material
i
For illustration purposes only. Actual data
on tires are specific to each vehicle and
may vary from data shown in above
illustration.
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,248
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Maximum loaded vehicle weight
The sum of curb weight, accessory weight,
total load limit, and production options
weight.
Maximum permissible tire inflation
pressure
This number is the greatest amount of air
pressure that should ever be put in the tire.
Normal occupant weight
The number of occupants the vehicle is
designed to seat, multiplied by 68 kilograms
(150 lb).
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 (Pounds per square inch)
A standard unit of measure for air pressure.
Recommended tire inflation pressure
The 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. It provides best
handling, tread life and riding comfort.
Supplemental 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 purchasers the
means

to easily identify such tires. The TIN is
comprised of “Manufacturer’s identification
mark”, “Tire size”, “Tire type code” and “Date
of manufacture”.
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
manufacturers 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 (speed symbol);
indicates the speed range for which a tire is
approved.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lb) times the vehicle’s
designated seating capacity.
Traction
The adhesive friction of a tire on a surface on
which

it moves. The amount of grip provided. 250
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