Load Range
While there is no industry-wide definition of ply rating, truck tires are 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 load range is identified on the tires sidewall. In the above illustration, the load range is a F. A tires load carrying capacity is affected by air pressure. The maximum load carrying capacity is attained by inflating the
tire to it's maximum rated air pressure. Proportionately, the lower the air pressure, the lower the tires load carrying capacity. The Load Range of the tire in the illustration is a F which indicates that the tire has 12
ply's. The maximum load and inflation for this tire is indicated on the sidewall. Note that it has different specifications when used as a single or dual rear wheel application. Manufacturers specify Load Indexes, Load Ranges, and Speed or Performance Ratings and Sizes
for all vehicles. When buying replacement tires it is always advisable to purchase tires that meet or exceed the manufacturers original specifications. Tires that have the incorrect load index may perform poorly, wear prematurely and potentially be a safety hazard!
| Load Range |
Ply Rating |
Load Pressure (PSI) |
| B |
4 |
35 |
| C |
6 |
50 |
| D |
8 |
65 |
| E |
10 |
80 |
| F |
12 |
95 |
|
|
