What Does 8PR, 10PR, and 14PR Mean on a Tire?
PR stands for ply rating — a strength equivalence, not a literal count of fabric layers. 6PR corresponds to load range C, 8PR to D, 10PR to E, 12PR to F, and 14PR to G. A higher ply rating means the tire is built to carry more weight at a higher inflation pressure.
Ply rating is a strength grade, not a layer count
Decades ago tires really did have 8 or 10 cotton plies. Modern radials achieve the same strength with one or two steel/polyester belts, so "8PR" now means "as strong as an old 8-ply tire." That's why the industry also uses load range letters — same information, newer label:
| Ply rating | Load range | Typical max pressure |
|---|---|---|
| 6PR | C | ~50 psi |
| 8PR | D | ~65 psi |
| 10PR | E | ~80 psi |
| 12PR | F | ~95 psi |
| 14PR | G | ~110 psi |
Why Texas trailer buyers see PR so often
Import trailer tire catalogs — and most Chinese-manufactured lines — still label by PR. When a spec sheet says ST235/80R16-14PR, that's a load range G tire at ~110 psi: heavy gooseneck and equipment-trailer territory.
Picking the right rating
- Match the trailer certification plate minimum — or go one step up if the trailer runs loaded at GVWR every day.
- Higher PR needs matching hardware: wheels rated for the pressure and high-pressure valve stems.
- Full capacity only exists at full rated pressure, checked cold.
Always verify against the tire's own sidewall marking and the manufacturer's load/inflation table.
Stocking dealer? We carry 6PR through 14PR trailer tires in the Dallas warehouse with live stock status — tier pricing here.