| 1 | PPX | Pioneer Products Co. | 4/1947-1/1952; eliminated 7/1953 | | NAKINA |
| 2 | PPX | Pittsburg Provision & Packing Co. | 8/1920-7/1932 | | NAKINA |
| 3 | PPX | Pioneer Products Co. | Jan-52 | | NRHS |
| 4 | PPX | *PITTSBURG PROVISION & PACKING CO. | | | PWRC |
| 5 | PPX | *PIONEER PRODUCTS CO. | | | PWRC |
| 6 | PPX | Pelham Parkway Express | | US-NY | TRAFFIC |
| 7 | PPXA | P P X | | | SCAC4 |
| 8 | PPXC | PIPER TRANS LLC | | | SCAC4 |
| 9 | PPXN | PROMP TRANS INC | | | SCAC4 |
| 10 | PPXO | PROPACE TRANSPORT INC | | | SCAC4 |
| 11 | PPXR | PIPER TRANSPORTATION | | | SCAC4 |
