Series/Model:
Companies
carry a variety of tires for various applications, depending on the needs
of the driver.
Sidewall
Abbrev.
XNW
= Extra Narrow White Sidewall
BSL=Black
Serrated Letters
BL=Black
Lettering
WL=White
Lettering
BW=
Black Sidwall
WS=White
Sidewall
RWL=Raised
White Letters
BXS=Black
Extra Narrow Segments
VSB=Vertical
Serrated Band
Weight:
Weight
of tire without inflation or rim.
Tire
Size & Service Description (e.g. P185/70R13 89T):
Overall
diameter:
The
diameter of an unloaded, inflated tire measured from the crown on one side
to the crown on the opposite side. The free radius equals one-half the
overall diameter. Sometimes called the outside diameter.
Overall
Width:
This
is the widest measurement of the tire from side-wall to side-wall. The
width of tire buldge at full inflation.
Tread
Width:
This
is the width of tread, side to side, in inches that actually contacts the
road suraface when tire has full inflation.
Static
Load Radius:
The
distance from the center of the axle to the ground under the specified
load at full inflation.
Revs/Mile:
Revolutions
per mile. The number of full rotations the wheel completes when a linear
mile is travelled.
Tread
Depth:
The
depth of grooves and channels on the wheel's contact surface. Deeper tread
depth permits water to drain away from the footprint, and may increase
in traction on snow or soft surfaces.
Tread
Wear Warranty:
The
milage up to which the tires may be driven on and still covered by the
manufacturer's warranty against defects.
UTQG
Rating
UTQG
is the Uniform Tire Quality Grading system. It is a series of a number
and two letters such as 320AB that represent the "3 T's" of tire grading:
Treadwear, Traction and Temperature ratings. The treadwear grade is based
on a standardized government test with a base index of 100. A tire
with a 320 treadwear rating would wear 3.2 times better than the government's
"base" tire. The traction letter (A, B or C) represent the tire's ability
to stop on wet pavement. "A" tires have the best wet pavement
traction in straight-ahead braking tests. The temperature letter (AA, A,
B or C) represent the tire's ability to dissipate heat and resist heat
generation
under controlled test. "AA" tires have the best heat resistance.
Load
Index Chart
Speed Rating | MPH | KPH |
N | 86 | 140 |
P | 93 | 150 |
Q | 100 | 160 |
R | 106 | 170 |
S | 112 | 180 |
T | 118 | 190 |
U | 124 | 200 |
H | 130 | 210 |
V | 149 | 240 |
W* | 168 | 270 |
Y* | 186 | 300 |