Cummins QSJ2.4G vs Generac SG040
The Cummins QSJ2.4G and Generac SG040 are both natural gas generator engines in a similar power class. Both are rated at roughly 50 kVA. Displacement is 2.4 L versus 4.43 L. The table below compares their full specifications side by side.
| Specification | Cummins QSJ2.4G | Generac SG040 |
|---|---|---|
| Headline rating | 50 kVA | 50 kVA |
| Standby (50 Hz) | — | — |
| Prime (50 Hz) | — | — |
| Standby (60 Hz) | 40 kWe | 40 kWe |
| Prime (60 Hz) | — | 36 kWe |
| Displacement | 2.4 L | 4.43 L |
| Configuration | L4 | L4 |
| Cylinders | 4 | 4 |
| Rated speed | 1,800 RPM | 1,800 RPM |
| Fuel | Natural Gas | Natural Gas |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | U.S. EPA Stationary | U.S. EPA Stationary |
| Dry weight | — | — |
| Origin | United States | United States |
Choosing between Cummins QSJ2.4G and Generac SG040
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.