Ford F-53 Motorhome Chassis (2017 year). Manual — part 27

*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 mile (1.6 kilometers).

*Recommended inflation
pressure: The cold inflation
pressure found on the Safety
Compliance Certification Label.
See the completed vehicle's
owner's manual for the location
of the Safety Compliance
Certification Label.

*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 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 - 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

Speed rating - 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.

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 for the correct
tire pressure for your vehicle. See
the completed vehicle's owner's
manual for the location of the
Safety Compliance Certification
Label.

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 1½ 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. See the
completed vehicle's owner's
manual for the location of the
Safety Compliance Certification
Label. The cold inflation pressure
should never be set lower than the
recommended pressure on the
vehicle label.

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.

A

B

C

B

D

E142544

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).