2015 Chevrolet City Express Owner Manual - Page 227
2015 Chevrolet City Express Manual
Page 227 highlights
10-44 Vehicle Care (UTQG) system does not apply to deep tread, winter tires, compact spare tires, tires with nominal rim diameters of 10 to 12 inches (25 to 30 cm), or to some limited-production tires. While the tires available on General Motors passenger cars and light trucks may vary with respect to these grades, they must also conform to federal safety requirements. Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum section width. For example: Treadwear 200 Traction AA Temperature A Warning (Continued) specific wheel and tire systems developed for the vehicle, and have them properly installed by a GM certified technician. See Buying New Tires on page 10-41 and Accessories and Modifications on page 10-3. Treadwear 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 course. For example, a tire graded 150 would wear one and one-half (1½) times as well on the government course as a tire graded 100. The relative performance of tires depends upon the actual conditions of their use, however, and may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate. Traction The traction grades, from highest to lowest, are AA, A, B, and C. Those grades represent the tire's ability to stop on wet pavement as measured under Uniform Tire Quality Grading The following information relates to the system developed by the United States National Highway Traffic Safety Administration (NHTSA), which grades tires by treadwear, traction, and temperature performance. This applies only to vehicles sold in the United States. The grades are molded on the sidewalls of most passenger car tires. The Uniform Tire Quality Grading All Passenger Car Tires Must Conform to Federal Safety Requirements In Addition To These Grades.