FORD 2014 F-550 v.2 - Manual (Page 262)

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.
mph ( km/h) 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
259
Super Duty (TFA)
Wheels and Tires