|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.
- More Than 100: Better
- 100: Baseline
- Less Than 100: Poorer
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.
A tire graded 200 would wear twice as long on the government test track as
one graded 100. Your actual tire mileage depends upon the conditions of
their use & may vary due to driving habits, service practices, differences
in road characteristics & climate. Note: Treadwear grades are valid only
for comparisons within a manufacturer's product line. They are not valid for
comparisons between manufacturers.
- AA: Best
- A: Better
- B: Good
- C: Fair
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.
- A: Best
- B: Intermediate
- C: Acceptable
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.
Temperature grades are representative of a properly inflated & not
overloaded tire. Excessive load, or underinflation, or excessive speed can
increase heat & lead to premature failure.