2000 Cadillac Catera Owners Manual

Uniform Tire Quality GradingQuality grades can be found where applicable on thetire sidewall between tread shoulder and maximumsection width. For example:Treadwear 200 Traction AA Temperature AThe following information relates to the systemdeveloped by the United States National HighwayTraffic Safety Administration, which grades tiresby treadwear, traction and temperature performance.(This applies only to vehicles sold in the United States.)The grades are molded on the sidewalls of mostpassenger car tires. The Uniform Tire Quality Gradingsystem does not apply to deep tread, winter-type snowtires, space-saver or temporary use spare tires, tires withnominal rim diameters of 10 to 12 inches (25 to 30 cm),or to some limited-production tires.While the tires available on General Motors passengercars and light trucks may vary with respect to thesegrades, they must also conform to Federal safetyrequirements and additional General Motors TirePerformance Criteria (TPC) standards.TreadwearThe treadwear grade is a comparative rating based onthe wear rate of the tire when tested under controlledconditions on a specified government test course.For example, a tire graded 150 would wear one and ahalf (1 1/2) times as well on the government courseas a tire graded 100. The relative performance oftires depends upon the actual conditions of their use,however, and may depart significantly from the normdue to variations in driving habits, service practicesand differences in road characteristics and climate.Traction -- AA, A, B, CThe traction grades, from highest to lowest, are AA,A, B, and C. Those grades represent the tire’s abilityto stop on wet pavement as measured under controlledconditions on specified government test surfaces ofasphalt and concrete. A tire marked C may have poortraction performance. Warning: The traction gradeassigned to this tire is based on straight-aheadbraking traction tests, and does not includeacceleration, cornering, hydroplaning, or peaktraction characteristics.6-43