Generac SG625 vs PSI 40L
The Generac SG625 and PSI 40L are both natural gas generator engines in a similar power class. Both are rated at roughly 797 kVA. Displacement is 33.9 L versus 39.23 L. The table below compares their full specifications side by side.
| Specification | Generac SG625 | PSI 40L |
|---|---|---|
| Headline rating | 781 kVA | 813 kVA |
| Standby (50 Hz) | — | 650 kWe |
| Prime (50 Hz) | — | 585 kWe |
| Standby (60 Hz) | 625 kWe | 800 kWe |
| Prime (60 Hz) | — | 725 kWe |
| Displacement | 33.9 L | 39.23 L |
| Configuration | V12 | V12 |
| Cylinders | 12 | 12 |
| Rated speed | 1,800 RPM | 1,500 / 1,800 RPM |
| Fuel | Natural Gas | Natural Gas |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | U.S. EPA Stationary | U.S. EPA Stationary |
| Dry weight | — | 3390 kg |
| Origin | United States | United States |
Choosing between Generac SG625 and PSI 40L
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 PSI 40L has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.