Federal Motor Vehicle Safety
Standard No. 139. Grades B and A
represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law.
Glossary of Tire Terminology
*Tire label: A label showing the
original equipment tire sizes,
recommended inflation pressure
and the maximum weight the
vehicle can carry.
*
Tire Identification Number
(TIN): A number on the sidewall
of each tire providing information
about the tire brand and
manufacturing plant, tire size and
date of manufacture. Also referred
to as DOT code.
*
Inflation pressure: A measure
of the amount of air in a tire.
*
Standard load: A class of
P-metric or Metric tires designed
to carry a maximum load at set
pressure. For example: For
P-metric tires
35 psi (2.4 bar) and
for Metric tires 36 psi (2.5 bar).
Increasing the inflation pressure
beyond this pressure will not
increase the tire ’s load carrying
capability.
*
Extra load: A class of P-metric
or Metric tires designed to carry a
heavier maximum load at
42 psi
(2.9 bar). Increasing the inflation
pressure beyond this pressure will
not increase the tire ’s load
carrying capability. *
kPa: Kilopascal, a metric unit of
air pressure.
*
PSI: Pounds per square inch, a
standard unit of air pressure.
*
Cold tire pressure: The tire
pressure when the vehicle has
been stationary and out of direct
sunlight for an hour or more and
prior to the vehicle being driven for
1 mi (1.6 km)
.
*
Recommended inflation
pressure: The cold inflation
pressure found on the Safety
Compliance Certification Label
(affixed to either the door hinge
pillar, door-latch post, or the door
edge that meets the door-latch
post, next to the driver's seating
position), or Tire Label located on
the B-Pillar or the edge of the
driver door.
* B-pillar: The structural member
at the side of the vehicle behind
the front door.
*
Bead area of the tire: Area of
the tire next to the rim.
*
Sidewall of the tire: Area
between the bead area and the
tread.
*
Tread area of the tire: Area of
the perimeter of the tire that
contacts the road when mounted
on the vehicle.
*Rim: The metal support (wheel)
for a tire or a tire and tube
assembly upon which the tire
beads are seated.
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Information Contained on the
Tire Sidewall
Both United States and Canada
Federal regulations require tire
manufacturers to place
standardized information on the
sidewall of all tires. This
information identifies and
describes the fundamental
characteristics of the tire and also
provides a U.S. DOT Tire
Identification Number for safety
standard certification and in case
of a recall.
Information on P Type Tires
P215/65R15 95H is an example of
a tire size, load index and speed
rating. The definitions of these
items are listed below. (Note that
the tire size, load index and speed
rating for your vehicle may be
different from this example.) A.
P: Indicates a tire, designated
by the Tire and Rim Association,
that may be used for service on
cars, sport utility vehicles,
minivans and light trucks. Note:
If
your tire size does not begin with
a letter this may mean it is
designated by either the European
Tire and Rim Technical
Organization or the Japan Tire
Manufacturing Association.
B. 215:
Indicates the nominal
width of the tire in millimeters
from sidewall edge to sidewall
edge. In general, the larger the
number, the wider the tire.
C. 65:
Indicates the aspect ratio
which gives the tire's ratio of
height to width.
D. R:
Indicates a radial type tire.
E. 15:
Indicates the wheel or rim
diameter in inches. If you change
your wheel size, you will have to
purchase new tires to match the
new wheel diameter.
F. 95:
Indicates the tire's load
index. It is an index that relates to
how much weight a tire can carry.
You may find this information in
your owner ’s manual. If not,
contact a local tire dealer.
Note: You may not find this
information on all tires because it
is not required by federal law.
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G.
H: Indicates the tire's speed
rating. The speed rating denotes
the speed at which a tire is
designed to be driven for extended
periods of time under a standard
condition of load and inflation
pressure. The tires on your vehicle
may operate at different
conditions for load and inflation
pressure. These speed ratings may
need to be adjusted for the
difference in conditions. The
ratings range from
81 mph
(130 km/h) to 186 mph
(299 km/h). These ratings are
listed in the following chart.
Note: You may not find this
information on all tires because it
is not required by federal law. Speed rating
Letter
rating
81 mph (130 km/h)
M
87 mph (140 km/h)
N
99 mph (159 km/h)
Q
106 mph (171 km/h)
R
112 mph (180 km/h)
S
118 mph (190 km/h)
T
124 mph (200 km/h)
U
130 mph (210 km/h)
H
149 mph (240 km/h)
V Speed rating
Letter
rating
168 mph (270 km/h)
W
186 mph (299 km/h)
Y
Note: For tires with a maximum
speed capability over 149 mph
(240 km/h), tire manufacturers
sometimes use the letters ZR. For
those with a maximum speed
capability over 186 mph (299
km/h), tire manufacturers always
use the letters ZR.
H. U.S. DOT Tire Identification
Number (TIN):
This begins with
the letters DOT and indicates that
the tire meets all federal
standards. The next two numbers
or letters are the plant code
designating where it was
manufactured, the next two are
the tire size code and the last four
numbers represent the week and
year the tire was built. For
example, the numbers 317 mean
the 31st week of 1997. After 2000,
the numbers go to four digits. For
example, 2501 means the 25th
week of 2001. The numbers in
between are identification codes
used for traceability. This
information is used to contact
customers if a tire defect requires
a recall.
I. M+S or M/S:
Mud and Snow, or
AT:
All Terrain, or
AS:
All Season.
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The tire suppliers may have
additional markings, notes or
warnings such as standard load
or radial tubeless.
Additional Information
Contained on the Tire Sidewall
for LT Type Tires
Note:
Tire Quality Grades do not
apply to this type of tire. LT type tires have some additional
information beyond those of P
type tires; these differences are
described below.
A.
LT: Indicates a tire, designated
by the Tire and Rim Association,
that is intended for service on light
trucks.
B. Load Range and Load
Inflation Limits:
Indicates the
tire's load-carrying capabilities
and its inflation limits. C.
Maximum Load Dual lb (kg)
at psi (kPa) cold:
Indicates the
maximum load and tire pressure
when the tire is used as a dual,
defined as four tires on the rear
axle (a total of six or more tires on
the vehicle).
D. Maximum Load Single lb
(kg) at psi (kPa) cold:
Indicates
the maximum load and tire
pressure when the tire is used as
a single, defined as two tires
(total) on the rear axle.
Information on T Type Tires
T145/80D16 is an example of a
tire size.
Note: The temporary tire size for
your vehicle may be different from
this example. Tire Quality Grades
do not apply to this type of tire.
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T type tires have some additional
information beyond those of P
type tires; these differences are
described below:
A.
T: Indicates a type of tire,
designated by the Tire and Rim
Association, that is intended for
temporary service on cars, sport
utility vehicles, minivans and light
trucks.
B. 145:
Indicates the nominal
width of the tire in millimeters
from sidewall edge to sidewall
edge. In general, the larger the
number, the wider the tire. C.
80:
Indicates the aspect ratio
which gives the tire's ratio of
height to width. Numbers of 70 or
lower indicate a short sidewall.
D. D:
Indicates a diagonal type tire.
R:
Indicates a radial type tire.
E. 16:
Indicates the wheel or rim
diameter in inches. If you change
your wheel size, you will have to
purchase new tires to match the
new wheel diameter.
Recommended Tire Pressures
and Inflating Your Tires
Safe operation of your vehicle
requires that your tires are
properly inflated. Remember that
a tire can lose up to half of its air
pressure without appearing flat.
Every day before you drive, check
your tires. If one looks lower than
the others, use a tire gauge to
check the pressure of all tires and
adjust if required.
At least once a month and before
long trips, inspect each tire and
check the tire pressure with a tire
gauge (including spare, if
equipped). Inflate all tires to the
inflation pressure recommended
by Ford Motor Company.
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WARNING
Under-inflation is the most
common cause of tire failures
and may result in severe tire
cracking, tread separation or
blowout, with unexpected loss of
vehicle control and increased risk
of injury. Under-inflation increases
sidewall flexing and rolling
resistance, resulting in heat
buildup and internal damage to
the tire. It also may result in
unnecessary tire stress, irregular
wear, loss of vehicle control and
accidents. A tire can lose up to
half of its air pressure and not
appear to be flat! You are strongly urged to buy a
reliable tire pressure gauge, as
automatic service station gauges
may be inaccurate. Ford
recommends the use of a digital
or dial-type tire pressure gauge
rather than a stick-type tire
pressure gauge. Use the
recommended cold inflation
pressure for optimum tire
performance and wear.
Under-inflation or over-inflation
may cause uneven treadwear
patterns. Always inflate your tires to the
Ford recommended inflation
pressure even if it is less than the
maximum inflation pressure
information found on the tire. You
will find a Tire Label containing
the Ford recommended tire
inflation pressure by the tire size
and other important information
located on the B-Pillar or the edge
of the driver
’s door.
The Ford recommended tire
inflation pressure is also found on
the Safety Compliance
Certification Label (affixed to
either the door hinge pillar,
door-latch post, or the door edge
that meets the door-latch on the
B-pillar, or on the edge of the
driver ’s door.
Failure to follow the tire pressure
recommendations can cause
uneven treadwear patterns and
adversely affect the way your
vehicle handles.
Inspecting Your Tires and
Wheel Valve Stems
Periodically inspect the tire treads
for uneven or excessive wear and
remove objects such as stones,
nails or glass that may be wedged
in the tread grooves. Check the tire
and valve stems for holes, cracks,
or cuts that may permit air
leakage and repair or replace the
tire and replace the valve stem.
Inspect the tire sidewalls for
cracking, cuts, bruises and other
signs of damage or excessive
wear. If internal damage to the tire
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Age
WARNING
Tires degrade over time
depending on many factors
such as weather, storage
conditions, and conditions of use
(load, speed, inflation pressure)
the tires experience throughout
their lives.
In general, tires should be
replaced after six years regardless
of tread wear. However, heat
caused by hot climates or
frequent high loading conditions
can accelerate the aging process
and may require tires to be
replaced more frequently.
You should replace your spare tire
when you replace the road tires or
after six years due to aging even if
it has not been used. U.S. DOT Tire Identification
Number
Both United States and Canada
Federal regulations require tire
manufacturers to place
standardized information on the
sidewall of all tires. This
information identifies and
describes the fundamental
characteristics of the tire and also
provides a U.S. DOT Tire
Identification Number for safety
standard certification and in case
of a recall. This begins with the letters DOT
and indicates that the tire meets
all federal standards. The next
two numbers or letters are the
plant code designating where it
was manufactured, the next two
are the tire size code and the last
four numbers represent the week
and year the tire was built. For
example, the numbers 317 mean
the 31st week of 1997. After 2000,
the numbers go to four digits. For
example, 2501 means the 25th
week of 2001. The numbers in
between are identification codes
used for traceability. This
information is used to contact
customers if a tire defect requires
a recall.
Tire Replacement
Requirements
Your vehicle is equipped with tires
designed to provide a safe ride
and handling capability.
WARNINGS
Only use replacement tires
and wheels that are the same
size, load index, speed rating and
type (such as P-metric versus
LT-metric or all-season versus
all-terrain) as those originally
provided by Ford. The
recommended tire and wheel size
may be found on either the Safety
Compliance Certification Label
(affixed to either the door hinge
pillar, door-latch post, or the door
edge that meets the door-latch
post, next to the driver ’s seating
position), or the Tire Label which
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WARNINGS
is located on the B-Pillar or edge
of the driver ’s door. If this
information is not found on these
labels, then you should contact
your authorized dealer as soon as
possible. Use of any tire or wheel
not recommended by Ford can
affect the safety and performance
of your vehicle, which could result
in an increased risk of loss of
vehicle control, vehicle rollover,
personal injury and death. To reduce the risk of serious
injury, when mounting
replacement tires and wheels, you
should not exceed the maximum
pressure indicated on the sidewall
of the tire to set the beads without
additional precautions listed
below. If the beads do not seat at
the maximum pressure indicated,
re-lubricate and try again.
When inflating the tire for
mounting pressures up to 20 psi
(1.38 bar) greater than the
maximum pressure on the tire
sidewall, the following
precautions must be taken to
protect the person mounting the
tire:
1. Make sure that you have the
correct tire and wheel size.
2. Lubricate the tire bead and
wheel bead seat area again. WARNINGS
3. Stand at a minimum of
12 ft
(3.66 m) away from the wheel
and tire assembly.
4. Use both eye and ear
protection.
For a mounting pressure more
than 20 psi (1.38 bar) greater than
the maximum pressure, a Ford
dealer or other tire service
professional should do the
mounting.
Always inflate steel carcass tires
with a remote air fill with the
person inflating standing at a
minimum of
12 ft (3.66 m) away
from the wheel and tire assembly. Important: Remember to replace
the wheel valve stems when the
road tires are replaced on your
vehicle.
It is recommended that the two
front tires or two rear tires
generally be replaced as a pair.
The tire pressure sensors mounted
in the wheels (originally installed
on your vehicle) are not designed
to be used in aftermarket wheels.
The use of wheels or tires not
recommended by Ford Motor
Company may affect the
operation of your tire pressure
monitoring system.
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