The Cummins/Onan X2.5-G2 is a 2.5 L 3-cylinder naturally aspirated engine rated at 1500 rpm. It powers generator sets from Cummins/Onan, including the X2.5 and X2.5 G2. It holds 8 L (2.1 gal) of oil and 11 L (2.9 gal) of coolant.
Also known as: Cummins X2.5-G2
Part of the Cummins/Onan X2.5 engine family — 3 variants share parts & fitment.
| Oil capacity | 8.0 L |
|---|---|
| Coolant capacity | 11.0 L |
| Displacement | 2.5 L |
| Cylinders | 3 |
| Aspiration | naturally aspirated |
| Rated speed | 1500 rpm |
How to read your Cummins/Onan engine serial & model number →
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Heavy Duty Dry replaceable element with restriction indicator | — | |||
| Fuel filter | Spin-on fuel filters with water separator | — | |||
| Oil filter | Spin-on full flow filter | — | |||
| Battery | 12-volt | — | |||
| Coolant | 50% ethylene glycol; 50% water | 11.0 l | — | ||
| Oil | 8.0 l | — |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Temperature | Limiting ambient temp.** (°C) | 50 | °C | ** @ 13 mm H20 |
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 | 11.0 l | Jacket Water After cooled cooling system design |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
The Cummins/Onan X2.5-G2 engine has an oil capacity of 8.0 liters.
The Cummins/Onan X2.5-G2 has a displacement of 2.5 liters with 3 cylinders.
The Cummins/Onan X2.5-G2 powers 2 generator set(s), including Cummins/Onan X2.5, Cummins/Onan X2.5 G2.