Uniform Tire Quality Grade (UTQG) Labeling
Treadware: a measurement of tread durability with a reference standard of 100. 200 would mean twice the standard.
Traction: the measurement of a tire's ability to stop on wet test surfaces&of asphalt and
concrete under
controlled conditions.
Traction Grades:
A: performed well on both surfaces
B: performed well on at least one of the surfaces
C: performed poorly on one or both of the surfaces.
Temp. Resistance Grades:
A: The tire withstood a 30mn run at 115 mph w/o failing.
B: The tire passed 100 mph but not 115 mph.
C: The tire failed to complete a half-hour at 100 mph (uuh, is it a Hot Wheels?).
Following the Department of Transportation, or DOT label, on the tire's sidewall is: the serial number of the tire manufacturer, manufacturing plant, tire size, and date of manufacture. Federal law requires that tire dealers record the DOT identification numbers along with the tire buyer's name and address. There may be a service description on the end of the size of a 2-digit load index and a speed rating letter.
US tire-speed rating is based on laboratory testing conditions;
European rating is based on actual road testing.
High-performance tires are rated S or greater and aspect ratios of 70
or less (typically less than 60). Conventional radials meet the minimum DOT standard of 85mph.
Speed symbols may currently be marked on a tire in one of three ways: 205/60ZR15; 205/60ZR15 89W; or 205/60R15 89W.
Aspect ratio is determined by dividing a tire's section height by its section width when the tire is
inflated to maximum air pressure, mounted on the approved measuring rim, and under no load. The shorter the sidewall, or lower the aspect ratio, the quicker the response from steering wheel to tire. Also, a low ratio means a wider tread contact area which reduces distortion, provides improved cornering, and usually gives a stiffer feel to the ride.