P Metric Designation Tires - A Comparison to Today's Alpha Designation Tires

A new passenger tire designation system was originated by the International Standards Organization (ISO) and has been approved by the U.S. Tire and Rim Association, Incorporated (T&RA) and the National Highway Traffic Safety Administration (NHTSA). This paper explains this P metric tire designation system and compares it in regard to load formula, endurance and wear performance, and dimensional tolerance criteria to the current T&RA alpha designation system in use on most U.S. passenger car tires.