Cummins Onan generators need regular oil changes.
All of these model use SAE30 or 15W-40 oil.
The oil capacity of each model is:
- 2500 – .5 qt
- 2800 – .6 qt
- 4000 – 1.6 qt
- 5500 – 2 qt
- 3600 – 1.6 qt
- 6500 – 2 qt
- 8000 – 3 qt
- 10k – 5.9 qt
- 12500 – 5.9 qt
The oil should changed every 100 hours or once a year.
