Load range (LOAD RANGE E)

How to read it

NHTSA’s booklet and Ford’s manual describe the load range as identifying the tire’s load-carrying capabilities and its inflation limits. FMVSS 139 requires the letter on the sidewall of LT tires, and FMVSS 119 on the tires it covers, which include trailer tires. Yokohama says light truck tires run from load range B to F, and that most on the market are C, D and E; USTMA’s example is LT245/75R16 120/116Q Load Range E. Passenger tires use standard load and extra load instead.

Also searched as: load range C, load range D, load range E, ply rating.

Load range and ply rating

Carlisle, a trailer tire maker, equates each letter with a ply rating: B is 4 ply, C 6 ply, D 8 ply and E 10 ply. It says ply rating is a strength index from the days when a tire’s construction was rated by counting its plies; a tire now built with 2 or 3 plies can have the strength of a 6- or 7-ply tire. The actual number of plies is a separate marking: FMVSS 139 requires it on the sidewall, apart from the load range.

Load range and pressure

BFGoodrich describes load range E as having a higher ply rating and higher maximum pressure than C or D. Bridgestone’s manual says the maximum pressure can differ between tires of the same load range: a load range C tire is not necessarily 50 psi. In its high speed test, FMVSS 139 inflates LT tires up to 295 mm wide to 320 kPa for load range C, 410 kPa for D and 500 kPa for E.