2009 Hyundai Elantra Owner's Manual - Page 302

Maintenance Tread wear WARNING - Tire age Tires degrade over time, even when they are not being used. Regardless of the remaining tread, it is recommended that tires tread, It is recommended that tires generally be replaced after 6 years of normal service. Heat caused by not climates or frequent high loading Conditions can accelerate the aging process. Failure to follow this Warning can result in sudden tire failure, which could lead to a loss of control and an accident involving serious injury or death. 4. Tire ply composition and material 5. Maximum permissible inflation pressure This number is the greatest amount of air pressure that should be put in the tire. Do not exceed the maximum permissible inflation pressure. Refer to the Tire and Loading Information label for recommended inflation pressure. 6. Maximum load rating This number indicates the maximum load in kilograms and pounds that can be carried by the tire. When replacing the tires on the vehicle, always use a tire that has the same load rating as the factory installed tire. 7. Uniform tire quality grading The number of layers or plies of rubber-coated fabric are in the tire. Tire manufacturers also must indicate the materials in the tire, which include steel, nylon, polyester, and others. The letter "R" means radial ply construction; the letter "D" means diagonal or bias ply construction; and the letter "B" means belted-bias ply construction. 7 40 Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum section width. For example: TREAD wear 200 TRACTION AA TEMPERATUE A The tread wear 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-ahalf times (1½) 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 because of variations in driving habits, service practices and differences in road characteristics and climate. These grades are molded on the side-walls of passenger vehicle tires. The tires available as standard or optional equipment on your vehicles may vary with respect to grade. Traction - AA, A, B & C The traction grades, from highest to lowest, are AA, A, B and C. Those grades represent the tires 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.