Tire load index
With new rules governing tariff taxation on foreign tires, specifically requiring most foreign manufacturers of ST tires to provide a speed rating on every tire’s sidewall, we are seeing them using a tire service description with a speed letter for the tire. Although the load index section of the service description is not the official load capacity measurement for ST and LT tires they are still allowed. Probably because someday that form of load capacity determination will be standardized for all DOT highway tires.
One of the shining problems with some ST tires is the fact that the Load Range system used for determining the tire’s load capacity is not always accurate without further explanations. The ST235/80R16E tires are, or have been, manufactured in three distinct load capacities, all identified as LRE. The actual load capacities can be 3420#, 3500# & 3520#, all at 80 PSI. The new ST tires with load index and speed letters will have a 123 load index for the 3420# tires and a 124 load index for the 3520# tires.
Nice to know information when your OE tires are really close to being maxed-out, and a need to know fact, when replacing 3520# tires that have been used on 7000# axles and you’re thinking about using a name brand with the 3420# tires which do not qualify for 7000# axles.
USN - RET
DOD - RET
SSA - RET