Cummins 4B3.9-G12 vs Perkins 903-27
The Cummins 4B3.9-G12 and Perkins 903-27 are both diesel generator engines in a similar power class. Both are rated at roughly 38 kVA. Displacement is 3.9 L versus 2.7 L. The table below compares their full specifications side by side.
| Specification | Cummins 4B3.9-G12 | Perkins 903-27 |
|---|---|---|
| Headline rating | 38 kVA | 38 kVA |
| Standby (50 Hz) | 30 kWe | — |
| Prime (50 Hz) | 25 kWe | — |
| Standby (60 Hz) | 35 kWe | 30.3 kWe |
| Prime (60 Hz) | 28 kWe | 27.4 kWe |
| Displacement | 3.9 L | 2.7 L |
| Configuration | L4 | L3 |
| Cylinders | 4 | 3 |
| Rated speed | 1,500 / 1,800 RPM | 1,800 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | Unregulated |
| Dry weight | — | 341 kg |
| Origin | China | United Kingdom |
Choosing between Cummins 4B3.9-G12 and Perkins 903-27
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.