Ford E-450 (2018 year). Manual — part 42

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 one and one-half (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

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
1.0 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.

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

H

I

J

K

L

M

A

B

C D

E

F

G

E142543

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.

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 81–186 mph
(130–299 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.

mph ( km/h)

Letter
rating

81 (130)

M

87 (140)

N

99 (159)

Q

106 (171)

R

112 (180)

S

118 (190)

T

124 (200)

U

130 (210)

H

149 (240)

V

mph ( km/h)

Letter
rating

168 (270)

W

186 (299)

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: 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.