2020 FORD GT Owners Manual

U.S. Department of
Transportation Tire quality
grades: The U.S. Department of
Transportation requires Ford
Motor Company to give you the
following information about tire
grades exactly as the government
has written it.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on a
specified government test course.
For example, a tire graded 150
would wear 1 ½ times as well on
the government course as a tire
graded 100. The relative
performance of tires depends
upon the actual conditions of their
use, however, and may depart
significantly from the norm due to
variations in driving habits, service
practices, and differences in road
characteristics and climate.
Traction AA A B C WARNING:
The traction
grade assigned to this tire is
based on straight-ahead braking
traction 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. The
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.
Temperature A B C 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 heat
buildup 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
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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 (241 kPa) and
for Metric tires
36 psi (248 kPa).
Increasing the inflation pressure
beyond this pressure will not
increase the tire capability.
*
Extra load: A class of P-metric
or Metric tires designed to carry a
heavier maximum load at
42 psi
(289 kPa). 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 ’s 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
93 mph (150 km/h)
P
99 mph (160 km/h)
Q
106 mph (170 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
168 mph (270 km/h)
W Speed rating
Letter
rating
186 mph (300 km/h)
Y
>
186 mph
(300 km/h)
ZR
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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J.
Tire Ply Composition and
Material Used: 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 the
sidewall, which include steel,
nylon, polyester, and others.
K. Maximum Load: Indicates the
maximum load in kilograms and
pounds that can be carried by the
tire. See 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), for the correct tire
pressure for your vehicle.
L. Treadwear, Traction and
Temperature Grades:
*Treadwear The treadwear grade
is a comparative rating based on
the wear rate of the tire when
tested under controlled conditions
on a specified government test
course. For example, a tire graded
150 would wear one and one-half
times as well on the government
course as a tire graded 100. *Traction: The traction grades,
from highest to lowest are AA, A,
B, and C. The 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.
*
Temperature: 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.
M. Maximum Inflation
Pressure:
Indicates the tire
manufacturers' maximum
permissible pressure or the
pressure at which the maximum
load can be carried by the tire. This
pressure is normally higher than
the vehicle manufacturer's
recommended cold inflation
pressure which can be 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 which is
located on the B-Pillar or the edge
of the driver ’s door. The cold
inflation pressure should never be
set lower than the recommended
pressure on the vehicle label.
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The tire suppliers may have
additional markings, notes or
warnings such as standard load
or radial tubeless.
Location of the Tire Label
You will find a Tire Label
containing tire inflation pressure
by tire size and other important
information located on the driver
’s
side door opening.
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 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.
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.
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!
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. The
Ford recommended tire inflation
pressure is 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 which is
located on the B-Pillar or the edge
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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.
Maximum Inflation Pressure is
the tire manufacturer's maximum
permissible pressure and the
pressure at which the maximum
load can be carried by the tire. This
pressure is normally higher than
the manufacturer ’s recommended
cold inflation pressure which can
be 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 which is
located on the B-Pillar or the edge
of the driver ’s door. The cold
inflation pressure should never be
set lower than the recommended
pressure on the Safety
Compliance Certification Label or
Tire Label.
When weather temperature
changes occur, tire inflation
pressures also change. A
43°F
(6°C) temperature drop can
cause a corresponding drop of
1 psi (6 kPa)
in inflation pressure.
Check your tire pressures
frequently and adjust them to the
proper pressure which can be
found on the Safety Compliance
Certification Label or Tire Label.
To check the pressure in your
tire(s): 1. Make sure the tires are cool,
meaning they are not hot from
driving even a mile.
Note: If you are checking tire
pressure when the tire is hot, (for
example, driven more than
1 mi
(1.6 km)), never bleed or reduce air
pressure. The tires are hot from
driving and it is normal for
pressures to increase above
recommended cold pressures. A
hot tire at or below recommended
cold inflation pressure could be
significantly under-inflated.
Note: If you have to drive a
distance to get air for your tire(s),
check and record the tire pressure
first and add the appropriate air
pressure when you get to the
pump. It is normal for tires to heat
up and the air pressure inside to go
up as you drive.
2. Remove the cap from the valve
on one tire, then firmly press
the tire gauge onto the valve
and measure the pressure.
3. Add enough air to reach the
recommended air pressure.
Note: If you overfill the tire, release
air by pressing on the metal stem
in the center of the valve. Then
recheck the pressure with your tire
gauge.
4. Replace the valve cap.
5. Repeat this procedure for each
tire, including the spare.
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6.
Visually inspect the tires to
make sure there are no nails or
other objects embedded that
could poke a hole in the tire
and cause an air leak.
7. Check the sidewalls to make sure there are no gouges, cuts
or bulges.
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
is suspected, have the tire
demounted and inspected in case
it needs to be repaired or replaced.
For your safety, tires that are
damaged or show signs of
excessive wear should not be used
because they are more likely to
blow out or fail.
Improper or inadequate vehicle
maintenance can cause tires to
wear abnormally. Inspect all your
tires, including the spare,
frequently, and replace them if
one or more of the following
conditions exist: Tire Wear
When the tread is worn down to
one sixteenth of an inch (2 mm),
tires must be replaced to help
prevent your vehicle from skidding
and hydroplaning. Built-in
treadwear indicators, or wear bars,
which look like narrow strips of
smooth rubber across the tread
will appear on the tire when the
tread is worn down to one
sixteenth of an inch (2 mm).
When the tire tread wears down
to the same height as these wear
bars, the tire is worn out and must
be replaced.
Damage
Periodically inspect the tire treads
and sidewalls for damage (such
as bulges in the tread or sidewalls,
cracks in the tread groove and
separation in the tread or
sidewall). If damage is observed
or suspected have the tire
inspected by a tire professional.
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