The Cummins/Onan 4BTAA3.3-G12 is a 3.3 L 4-cylinder turbocharged & charge air cooled engine rated at 1800 rpm, producing up to 74 kW. It powers generator sets from Cummins/Onan, including the C40D6R and C60D6R. It holds 7.9 L (2.1 gal) of oil and 13 L (3.4 gal) of coolant.
Also known as: Cummins 4BTAA3.3-G12
Part of the Cummins/Onan 4BTAA3.3 engine family — 10 variants share parts & fitment.
| Oil capacity | 7.9 L |
|---|---|
| Coolant capacity | 13.0 L |
| Displacement | 3.3 L |
| Cylinders | 4 |
| Aspiration | Turbocharged & Charge Air Cooled |
| Rated speed | 1800 rpm |
| Gross power | 74 kW |
How to read your Cummins/Onan engine serial & model number →
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Fuel filter | Spin on fuel filters with water separator; 10-micron spin-on fuel filter element with water separator, Water-in-Fuel (WIF) sensor and WIF sensor harness | — | |||
| Oil filter | Spin on full flow filter | — | |||
| Oil | 7.9 l | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Valve clearance | Check | 2000 hr | First service — Valve clearance checks not required until 2,000 hours, twice the industry standard. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Coolant | 50% (Ethylene Glycol) : 50% (Water) | 13.0 l | Cooling system design: Jacket Water cooled |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Part # | Description | Category |
|---|---|---|
| PI144D1 | Alternator Model | alternator |
| UC274C | Alternator Model | alternator |
| UC274K | Alternator Model | alternator |
| V2403-M-E3BG | Engine Model | other_service |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
The Cummins/Onan 4BTAA3.3-G12 engine has an oil capacity of 7.9 liters.
The Cummins/Onan 4BTAA3.3-G12 has a displacement of 3.3 liters with 4 cylinders.
The Cummins/Onan 4BTAA3.3-G12 powers 2 generator set(s), including Cummins/Onan C40D6R, Cummins/Onan C60D6R.