Cummins QSB5.9-G31 vs Detroit Diesel 8V71
The Cummins QSB5.9-G31 and Detroit Diesel 8V71 are both diesel generator engines in a similar power class. Both are rated at roughly 156 kVA. Displacement is 5.9 L versus 9.3 L. The table below compares their full specifications side by side.
| Specification | Cummins QSB5.9-G31 | Detroit Diesel 8V71 |
|---|---|---|
| Headline rating | 156 kVA | 156 kVA |
| Standby (50 Hz) | 125 kWe | 125 kWe |
| Prime (50 Hz) | 100 kWe | 113 kWe |
| Standby (60 Hz) | — | 150 kWe |
| Prime (60 Hz) | — | 135 kWe |
| Displacement | 5.9 L | 9.3 L |
| Configuration | L6 | V8 |
| Cylinders | 6 | 8 |
| Rated speed | 1,500 RPM | 1,500 / 1,800 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | Unregulated |
| Dry weight | — | — |
| Origin | China | United States |
Choosing between Cummins QSB5.9-G31 and Detroit Diesel 8V71
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.