Uniform Tire Quality Grading System (UTQG)
Except for snow tires, US federal authorities require manufacturers to grade passenger car tires based on three factors: tread wear, traction, and temperature resistance.
Tread Wear
This grade measures the wear rate of the tire when tested under controlled conditions. "100" is taken to represent a basic quality standard, and a tire graded "200" would wear twice as long on the test track as one graded "100". More than 100 is better, with 100 being the baseline, and less than 100 being poorer. Note: Tread wear grades are valid only for comparisons within a manufacturer's product line. They are not valid for comparisons between manufacturers.
Traction
Traction grades represent the tire's ability to stop on wet pavement. The grade is based upon "straight ahead" braking tests, and does not indicate cornering ability. "A" is best, "B" is intermediate, and "C" is acceptable.
Temperature
The temperature grades represent the tire's resistance to the generation of heat, from "A" (Best) through "B" (Intermediate) to "C" (Acceptable). Note: Federal law requires that all tires meet at least the minimal requirements of Grade C.
