2009 Mercury Sable Owner's Manual - Page 184

Tires, Wheels and Loading 12. Treadwear, Traction and Temperature Grades • 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 (11⁄2) times as well on the government course as a tire graded 100. • Traction: The traction grades, from highest to lowest are AA, A, B, and C. The grades represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. A tire marked C may have poor traction performance. • Temperature: The temperature grades are A (the highest), B and C, representing the tire's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. 13. Maximum Permissible Inflation Pressure: Indicates the tire manufacturers' maximum permissible pressure and/or the pressure at which the maximum load can be carried by the tire. This pressure is normally higher than the manufacturer's recommended cold inflation pressure which can be found on the Safety Compliance Certification Label or Tire Label which is located on the B-Pillar or the edge of the driver's door. The cold inflation pressure should never be set lower than the recommended pressure on the vehicle label. The tire suppliers may have additional markings, notes or warnings such as standard load, radial tubeless, etc. 184 2009 Sable (mgo) Owners Guide, 2nd Printing USA (fus)