12 40–45 kw bi-fuel (ng/lp) generator models side by side — power, phase, sound level, weight and fuel tank capacity, compiled from manufacturer specification sheets.
| Model | Standby | Phase | Sound | Weight | Fuel tank |
|---|---|---|---|---|---|
| Generac QT 3.9L 40kW | 40.0 kW | 1-phase or 3-phase | — | — | — |
| Olympian G40F3 | 40.0 kW | 3 | — | — | — |
| Cummins/Onan C40 N6 | 40.0 kW | 1 or 3 | 63.0 dBA | 1508.0 kg | — |
| Kohler KG40 | 40.0 kW | 3 | — | 807.0 kg | — |
| Generac XG04045 | 40.0 kW | 1 or 3 | 64.0 dBA | 689.0 kg | — |
| Cummins/Onan GGPB | 40.0 kW | 3-phase, 1-phase | — | 819.0 kg | 225.0 L |
| Cummins/Onan RS 40 | 40.0 kW | 1 | 63.0 dBA | 615.0 kg | — |
| Cummins/Onan RX 40 | 40.0 kW | 1 | 71.0 dBA | 567.0 kg | — |
| Generac QT040 | 40.0 kW | Single/Three | 73.0 dBA | — | — |
| Generac G40LG2 | 40.0 kW | 3 | — | 714.0 kg | — |
| Cummins/Onan 42GGFE | 42.0 kW | 1 or 3 | 66.3 dBA | 1160.0 kg | — |
| Kohler 48RCLC | 44.0 kW | 1Ø and 3Ø | 61.0 dBA | 767.0 kg | — |
Among 40–45 kW Bi-Fuel (NG/LP) generators in this comparison, the Kohler 48RCLC is quietest at 61.0 dBA.
Among 40–45 kW Bi-Fuel (NG/LP) generators in this comparison, the Cummins/Onan RX 40 is lightest at 567.0 kg dry weight.
Not every model reports every spec — blanks mean the source document didn't state that figure, not that the value is zero.