One of the most critical aspects of maintaining a diesel generator is monitoring and managing the engine oil capacity. Using the correct amount and type of engine oil ensures smooth operation, prevents engine wear, and extends the generator’s lifespan.
Different generators come in varying sizes and power ratings, from small portable units to large industrial sets, and each has its own oil capacity requirements.
Diesel Generator Engine Oil Capacity
Portable Generators
| Generator Type / Model | Engine Displacement (cc/L) | Oil Capacity (Liters) | Oil Capacity (Quarts) |
|---|---|---|---|
| Honda EM5000SX | 389 cc | 1.1 L | 1.2 qt |
| Honda EB10000 | 688 cc | 1.9 L | 2.0 qt |
| Generac XD5000E | 435 cc | 1.6 L | 1.7 qt |
| Yanmar L100V | 435 cc | 1.6 L | 1.7 qt |
| Yamaha EF2000iS | 79 cc | 0.4 L | 0.4 qt |
| Yamaha EF7200DE | 357 cc | 1.3 L | 1.4 qt |
| Briggs & Stratton 30675 Q6500 | 420 cc | 1.4 L | 1.5 qt |
| Champion 3500-Watt | 224 cc | 0.6 L | 0.6 qt |
| Westinghouse WGen7500 | 420 cc | 1.1 L | 1.2 qt |
| DuroMax XP12000EH | 457 cc | 1.5 L | 1.6 qt |
| Wen 5613K | 389 cc | 1.1 L | 1.2 qt |
| Pulsar PG10000 | 420 cc | 1.1 L | 1.2 qt |
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Standby Generators
| Generator Type / Model | Engine Displacement (cc/L) | Oil Capacity (Liters) | Oil Capacity (Quarts) |
|---|---|---|---|
| Generac Protector QS 20kW | 2.2 L | 5.7 L | 6.0 qt |
| Generac Industrial 150kW | 8.9 L | 27.0 L | 28.5 qt |
| Cummins Onan QD 6000 | 719 cc | 2.0 L | 2.1 qt |
| Cummins Onan QD 12500 | 1.6 L | 5.7 L | 6.0 qt |
| Kohler 30REOZK | 2.9 L | 6.6 L | 7.0 qt |
| Kohler 200REOZVB | 8.9 L | 27.0 L | 28.5 qt |
| Briggs & Stratton 20kW | 1.0 L | 4.0 L | 4.2 qt |
| Guardian 22kW | 2.4 L | 6.0 L | 6.3 qt |
| Kohler 14RESA | 725 cc | 1.9 L | 2.0 qt |
| Cummins RS50 | 3.9 L | 9.5 L | 10.0 qt |
| Generac Centurion 35kW | 3.9 L | 10.0 L | 10.6 qt |
| Eaton 40kW | 4.5 L | 12.0 L | 12.7 qt |
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Industrial Generators
| Generator Type / Model | Engine Displacement (cc/L) | Oil Capacity (Liters) | Oil Capacity (Quarts) |
|---|---|---|---|
| Cummins KTA19-G3 | 19 L | 50.0 L | 52.8 qt |
| Cummins QSK60 | 60 L | 230.0 L | 243.0 qt |
| Caterpillar C1.5 | 1.5 L | 6.5 L | 6.9 qt |
| Caterpillar C7.1 | 7.1 L | 25.0 L | 26.4 qt |
| Caterpillar C15 | 15.2 L | 42.0 L | 44.4 qt |
| Caterpillar 3516B | 69 L | 250.0 L | 264.0 qt |
| Perkins 403A-11G | 1.1 L | 4.9 L | 5.2 qt |
| Perkins 1104A-44TG2 | 4.4 L | 8.3 L | 8.8 qt |
| Perkins 4016-61TRG3 | 61 L | 177.0 L | 187.0 qt |
| John Deere 6068HF285 | 6.8 L | 24.0 L | 25.4 qt |
| John Deere 6135HF485 | 13.5 L | 40.0 L | 42.3 qt |
| Detroit Diesel Series 60 | 14.0 L | 36.0 L | 38.0 qt |
| Scania DC16 084A | 16.4 L | 45.0 L | 47.6 qt |
| Baudouin 6M26.3 | 15.9 L | 40.0 L | 42.3 qt |
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Marine Generators
| Generator Type / Model | Engine Displacement (cc/L) | Oil Capacity (Liters) | Oil Capacity (Quarts) |
|---|---|---|---|
| Yanmar 6EY18AL | 18 L | 50.0 L | 52.8 qt |
| Cummins Onan MDKDL | 2.5 L | 7.0 L | 7.4 qt |
| Cummins Onan MDKBR | 3.9 L | 10.0 L | 10.6 qt |
| Westerbeke 8.0 EDT D-NET | 1.8 L | 5.0 L | 5.3 qt |
| Northern Lights M843NK | 2.2 L | 6.5 L | 6.9 qt |
| Fischer Panda 8000i | 1.3 L | 4.5 L | 4.8 qt |
| Kohler 9EKOZD | 1.4 L | 5.2 L | 5.5 qt |
| Onan e-QD MDKAV | 2.0 L | 6.0 L | 6.3 qt |
Heavy-Duty Generators
| Generator Type / Model | Engine Displacement (cc/L) | Oil Capacity (Liters) | Oil Capacity (Quarts) |
|---|---|---|---|
| Mitsubishi S6R | 22 L | 56.0 L | 59.0 qt |
| Mitsubishi S16R | 65 L | 180.0 L | 190.0 qt |
| Volvo Penta TAD1641GE | 16.1 L | 48.0 L | 50.7 qt |
| Volvo Penta D13 | 12.8 L | 33.0 L | 34.9 qt |
| Doosan DP158LD | 14.6 L | 36.0 L | 38.0 qt |
| Doosan P180LE-1 | 18 L | 48.0 L | 50.7 qt |
| MTU 16V4000 | 76.3 L | 260.0 L | 274.7 qt |
| MTU 20V4000 | 95.3 L | 300.0 L | 317.0 qt |
| Cummins QST30-G5 | 30.5 L | 154.0 L | 162.8 qt |
| Perkins 2806A-E18TAG2 | 18.1 L | 55.0 L | 58.1 qt |
| Baudouin 12M33.2 | 39.2 L | 110.0 L | 116.2 qt |
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Compact Generators
| Generator Type / Model | Engine Displacement (cc/L) | Oil Capacity (Liters) | Oil Capacity (Quarts) |
|---|---|---|---|
| Deutz BF4M2011 | 4.0 L | 7.0 L | 7.4 qt |
| Deutz BF6M1013EC | 7.2 L | 18.0 L | 19.0 qt |
| Deutz TCD2015 V08 | 15.9 L | 42.0 L | 44.4 qt |
| Mahindra Powerol 40 kVA | 3.0 L | 8.0 L | 8.5 qt |
| Mahindra Powerol 160 kVA | 8.2 L | 24.0 L | 25.4 qt |
| Lister Petter TR2 | 1.0 L | 3.6 L | 3.8 qt |
| Lister Petter TR3 | 1.5 L | 5.4 L | 5.7 qt |
| Kubota D1105 | 1.1 L | 5.1 L | 5.4 qt |
| Kubota V3600 | 3.6 L | 13.2 L | 13.9 qt |
| Isuzu 4LE2 | 2.2 L | 8.5 L | 9.0 qt |
| Hatz 4H50TIC | 2.0 L | 6.7 L | 7.1 qt |
| Kirloskar EA16 | 1.6 L | 5.5 L | 5.8 qt |
Note: Oil capacities may vary slightly depending on specific configurations and whether the oil filter is included.
Factors Affecting Oil Capacity
1. Engine Size and Displacement
Larger displacement engines naturally hold more oil. For example, a portable Honda generator may only need 1.1 liters, while an industrial Perkins engine can require over 170 liters.
2. Power Output
Higher power output engines typically consume more oil because they operate under heavier loads and generate more heat.
3. Cooling System
Air-cooled generators generally have lower oil capacity, while water-cooled engines, common in large units, require larger oil reservoirs.
4. Operating Conditions
Generators running in dusty, hot, or humid environments may need more frequent oil changes, though capacity itself remains the same.
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Recommended Oil Types for Diesel Generators
While the oil capacity differs across models, most manufacturers recommend using high-quality heavy-duty diesel engine oils that meet API CI-4, CJ-4, CK-4, or ACEA standards. Commonly used viscosities include:
- 15W-40: The most widely recommended oil for medium to large diesel engines.
- 10W-30: Suitable for smaller generators and colder climates.
- 5W-40 Synthetic: Provides excellent cold start protection and extended drain intervals.
Maintenance Tips for Diesel Generator Oil
- Check oil levels before every operation to avoid running with low oil.
- Change oil and filters regularly according to manufacturer intervals (typically every 100–250 hours).
- Use genuine filters and recommended oil to prevent sludge buildup.
- Keep records of oil changes for long-term maintenance and warranty claims.
FAQs
How much oil does a diesel generator take?
The oil capacity of a diesel generator varies widely depending on the size and engine type. Small portable units may require just 1–2 liters, while large industrial generators can hold anywhere from 20 to over 200 liters of oil. Always check the manufacturer’s manual for the exact specification.
Can I use 15W-40 in a diesel generator?
Yes. 15W-40 engine oil is the most commonly recommended grade for diesel generators, especially for medium and large engines. It provides excellent lubrication, wear protection, and stability under high temperatures. However, for colder climates or smaller engines, 10W-30 or synthetic 5W-40 may be more suitable.
How much oil does a 7 kVA generator hold?
A 7 kVA diesel generator typically holds between 3 to 6 liters of engine oil, depending on the brand and engine design. For instance, smaller models with single-cylinder engines require less oil, while multi-cylinder units at the same kVA rating may need more.
How many litres of diesel generator?
If you’re asking about engine oil capacity, it ranges from 1 liter in portable models to over 180 liters in industrial sets. If the question refers to fuel tank size, diesel generators can have tanks ranging from 10 liters in small portables to thousands of liters in industrial standby units.
How much oil does a 5 kVA diesel generator hold?
A 5 kVA diesel generator usually holds about 2 to 4 liters of oil. The exact capacity depends on the engine displacement and cooling system. It’s important to avoid overfilling, as excess oil can cause foaming and damage seals.
How much oil does a Onan 7500 diesel generator hold?
The Cummins Onan 7500 Quiet Diesel Generator holds approximately 3.0 liters (3.2 quarts) of engine oil. Always use high-quality oil that meets API CI-4 or CJ-4 standards and follow the recommended change intervals (usually every 150–200 hours of operation).
Final Thoughts
The diesel generator engine oil capacity varies widely depending on the brand, size, and application, from less than 2 liters in portable units to over 180 liters in massive industrial engines. Keeping track of the correct oil level and using the right oil type ensures your generator performs reliably whenever you need it most.
