Prefix Letters used by the Tire and Rim Association in Tire Size Designations and Their Definitions

Posted by Petra on 2/4/2012 to Trailer Tires FAQ
PREFIX LETTERS USED BY THE TIRE AND RIM ASSOCIATION
IN TIRE SIZE DESIGNATIONS AND THEIR DEFINITIONS

Prefix letters are included, when necessary, as part of Tire Size Designations to differentiate between tires designed for service conditions which
may require different loads and inflations and/or tires designed for, and which must be used on, different types of rims.

LT — Identifies a tire primarily intended for service on light trucks.

SUFFIX LETTERS USED BY THE TIRE AND RIM ASSOCIATION
IN TIRE SIZE DESIGNATIONS AND THEIR DEFINITIONS

Suffix letters are included, when necessary, as part of Tire Size Designations to differentiate between tires designed for service conditions which
may require different loads and inflation's and/or tires designed for, and which must be used on, different types of rims.

LT — Light Truck tires for service on Trucks, Busses, Trailers and Multi-Purpose Passenger Vehicles used in normal highway service. For nominal
rim diameters ending in a whole number, a 5° tapered bead seat rim is used; for nominal rim diameters ending in XX.5, a 15° tapered bead
seat is used. This suffix is intended to differentiate among tires for Passenger Car, Truck/Bus and other vehicles or other services which use
a similar designation.

Example: 7.00-15, 7.00-15LT, 7.00-15TR.

TR — Tires for service on Trucks, Busses and other vehicles with rims having specified rim diameter of nominal +.156” or +.250”. This suffix is
intended to differentiate among tires for Passenger Car, Light Truck, and other vehicles or other services which use similar designations.

Example: 7.00-15, 7.00-15LT, 7.00-15NHS and 7.00-15TR.

HC — Identifies a heavy-duty tire designated for use on “HC” 15° tapered rims used on Trucks, Busses and other vehicles. This suffix
is intended to differentiate among tires for Light Trucks and other vehicles or other services which use a similar designation.

Example: 8R17.5LT, 8R17.5HC.
Tire Article thanks to Goodyear Tires