Cummins QSB6.7-G31 vs Isuzu 6UZ1X
The Cummins QSB6.7-G31 and Isuzu 6UZ1X are both diesel generator engines in a similar power class. Both are rated at roughly 282 kVA. Displacement is 6.7 L versus 9.839 L. The table below compares their full specifications side by side.
| Specification | Cummins QSB6.7-G31 | Isuzu 6UZ1X |
|---|---|---|
| Headline rating | 281 kVA | 282 kVA |
| Standby (50 Hz) | 225 kWe | 225.7 kWe |
| Prime (50 Hz) | 180 kWe | 205.2 kWe |
| Standby (60 Hz) | — | 257.4 kWe |
| Prime (60 Hz) | — | 234 kWe |
| Displacement | 6.7 L | 9.839 L |
| Configuration | L6 | L6 |
| Cylinders | 6 | 6 |
| Rated speed | 1,500 RPM | 1,500 / 1,800 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | Euro Stage IIIA / U.S. EPA Tier 3 |
| Dry weight | — | — |
| Origin | China | Japan |
Choosing between Cummins QSB6.7-G31 and Isuzu 6UZ1X
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. The Isuzu 6UZ1X has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.