Explanation of Tire Data Fields

The company manufacturing this tire.

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 of tire without inflation or rim.

Tire Size & Service Description (e.g. P185/70R13 89T):

Approved Rim (measured):
This is the suggested rim width range that the specific tire should be mounted to. The number in parenthesis is the rim used to obtain other values in this chart, such as over-all width.

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.

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 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
*ZR classifications for these wheels are for vehicles capable of over 150mph/240 kph but NOT exceeding 168mph/270kph or 185mph/300kph respectively.
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