Caterpillar 3408 vs Cummins QSG12-G4
Compare Caterpillar 3408 and Cummins QSG12-G4 by recorded output, operating duty, frequency and engine specifications. Their listed displacements are 18 L and 11.8 L, respectively. Start with the same duty and frequency, then check each model’s source and package conditions. These records alone do not establish interchangeability.
| Specification | Caterpillar 3408 | Cummins QSG12-G4 |
|---|---|---|
| Standby electrical (50 Hz) | 365 kWe | 364 kWe |
| Prime electrical (50 Hz) | 330 kWe | 333 kWe |
| Standby electrical (60 Hz) | 440 kWe | 418 kWe |
| Prime electrical (60 Hz) | 400 kWe | 383 kWe |
| Displacement | 18 L | 11.8 L |
| Configuration | V8 | L6 |
| Cylinders | 8 | 6 |
| Recorded engine speed | 1,800 RPM | 1,500 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Recorded emissions classification | U.S. EPA Tier 2 | Unregulated |
| Dry weight | Not listed | 1,110 kg |
| Origin | United States | China |
Compare matching ratings
Read across a row to compare the same operating duty and frequency. kWe is electrical output; mechanical kW is power at the engine shaft. kVA is apparent electrical power and is shown only when kWe is missing, without converting it. “Not listed” means the record lacks that rating, not zero output. Continuous and prime duties are kept separate. Check source documents, units and site conditions before comparing values.
An emissions classification in the catalog is not proof of certification for your engine or installation. Confirm the exact model, applicable documents and generator configuration.
Caterpillar 3408: Review the model record and available supporting documents
Cummins QSG12-G4: Review the model record and available supporting documents
Choosing between Caterpillar 3408 and Cummins QSG12-G4
Use this comparison as an engineering shortlist, then confirm the complete generator package against load profile, voltage, 50/60 Hz frequency, duty class, emissions rules, cooling margin, altitude, ambient temperature, enclosure design, controller features, and alternator sizing.