Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4717489 | Heavy duty diesel engine oil blend | — | 1988-01-05 |
| 4402841 | Extended service 5W-40 motor oil | — | 1983-09-06 |
| 4234409 | Process for the production of lubricating blend stocks | John H. Steffens | 1980-11-18 |