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Sumitomo Tire Quality Grading System
| Uniform Tire Quality Grading System or UTQG,
is the standard by which tire manufacturers rate the quality of their tires.
With the exception of snow tires, the DOT requires the manufacturers to
grade passenger car tires based on three performance factors: treadwear,
traction, & temperature resistance. Tread Wear
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 track.
Traction grades represent the tire's ability to stop on
wet pavement as measured under controlled conditions on specified government
test surfaces of asphalt & concrete. The Traction grade is based upon
"straight ahead" braking tests; it does not indicate cornering ability.
The temperature grades represent the tire's resistance to
the generation of heat when tested under controlled conditions on a
specified indoor laboratory test wheel. Sustained high temperatures can
cause the materials of the tire to degenerate & thus reduce tire life.
Excessive temperatures can lead to tire failure. Federal law requires that
all tires meet at least the minimal requirements of Grade C. |