This SAE Recommended Practice provides tire dimensions and uniform laboratory test procedures for evaluating certain essential characteristics of new pneumatic tires intended primarily for highway use on trucks, buses, trailers, and multipurpose passenger vehicles. (The requirements and test procedures published in this SAE Recommended Practice pertain to tire sizes currently used in the United States on trucks, buses, trailers, and multipurpose passenger vehicles. For related information on tire sizes not listed, contact Society of Automotive Engineers, Inc., Detroit Branch Office, 18121 East Eight Mile Road, East Detroit, Michigan 48021.)