While there is no industry-wide definition of Load Range, truck tires are frequently marked with ply rating and equivalent Load Range. These markings are used to identify the load and inflation limits of that particular tire, when used in a specific type of service.

     The speed rating is the maximum service speed of a passenger car tire. Light truck tires are not speed rated. Here are a list of Goodyear's passenger tire rating indicators and their mile-per-hour equivalents. This rating system applies to all tire markers.