Niigata 18V28AGS vs Wärtsilä 12V34SG
The Niigata 18V28AGS and Wärtsilä 12V34SG are both natural gas generator engines in a similar power class. Both are rated at roughly 7,400 kVA. Displacement is 432 L versus 435.9 L. The table below compares their full specifications side by side.
| Specification | Niigata 18V28AGS | Wärtsilä 12V34SG |
|---|---|---|
| Headline rating | 7,500 kVA | 7,300 kVA |
| Standby (50 Hz) | — | — |
| Prime (50 Hz) | 6,000 kWe | 5,840 kWe |
| Standby (60 Hz) | — | — |
| Prime (60 Hz) | — | 5,580 kWe |
| Displacement | 432 L | 435.9 L |
| Configuration | V18 | V12 |
| Cylinders | 18 | 12 |
| Rated speed | 750 RPM | 750 / 900 RPM |
| Fuel | Natural Gas | Natural Gas |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | Unregulated |
| Dry weight | — | — |
| Origin | Japan | Finland |
Choosing between Niigata 18V28AGS and Wärtsilä 12V34SG
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 Niigata 18V28AGS has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.