55 40–45 kw diesel 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 |
|---|---|---|---|---|---|
| Caterpillar D40-6 | 40.0 kW | Single | — | — | — |
| Caterpillar D40 | 40.0 kW | 3 phase | — | 306.0 kg | 4.4 L |
| Perkins 1103A-33TG1 | 40.0 kW | — | 88.2 dBA | 420.0 kg | — |
| MTU 4R0113 DS40 | 40.0 kW | 3 | 80.5 dBA | 943.0 kg | — |
| MTU MTU 4R0113 DS40 | 40.0 kW | — | 80.5 dBA | 943.0 kg | — |
| Cummins/Onan C40 D6 | 40.0 kW | 1/3 | — | 622.0 kg | 200.0 L |
| Cummins/Onan 40.0DDB-515R | 40.0 kW | — | — | — | — |
| Kohler 40EOZ | 40.0 kW | 1 and 3 | — | 1000.0 kg | — |
| Kohler 40EFOZ | 40.0 kW | 1 and 3 | — | 1052.0 kg | — |
| Kohler 40EKOZD | 40.0 kW | 1 | — | 551.0 kg | — |
| Cummins/Onan 40 DGBC | 40.0 kW | 1 or 3 | — | — | — |
| Cummins/Onan MDDC | 40.0 kW | 1 | 72.0 dBA | 1320.0 kg | — |
| FG Wilson P50E1 | 40.0 kW | — | 98.0 dBA | 850.0 kg | 250.0 L |
| Cummins/Onan DGBC | 40.0 kW | 3-phase | — | 757.0 kg | 24.0 L |
| Cummins/Onan DGCA | 40.0 kW | three-phase | — | 780.0 kg | 24.0 L |
| Cummins/Onan DGDA | 40.0 kW | 1 or 3 | 70.0 dBA | 1141.0 kg | 25.0 L |
| Iveco/FPT GE NEF 45M | 40.0 kW | — | — | — | — |
| Iveco/FPT GS NEF 45M | 40.0 kW | — | — | — | — |
| Cummins/Onan DGCB | 40.0 kW | three-phase | 67.0 dBA | 97.0 kg | 25.0 L |
| Emsa E BD XX 0050 | 40.0 kW | — | — | 1105.0 kg | 101.0 L |
| Kohler 40REOZJ | 40.0 kW | 3 | — | — | — |
| Cummins/Onan C40D6R | 40.0 kW | Wye, 3-phase | — | 1490.0 kg | — |
| Generac Guardian Liquid-cooled 40 kW Generator | 40.0 kW | single-phase | — | — | — |
| Cummins/Onan DGAE | 40.0 kW | I,3 | — | — | — |
| Cummins/Onan DEG-515R | 40.0 kW | 1 | — | — | — |
| Cummins/Onan 36 DGBC | 40.0 kW | Three | — | — | 197.0 L |
| SDMO JS40UCM | 40.0 kW | 1 | — | — | — |
| FG Wilson P50-3_50Hz | 40.0 kW | Three-phase | — | 341.0 kg | 143.0 L |
| Olympian GEP50-7 | 40.0 kW | — | — | 871.0 kg | 219.0 L |
| Kohler 45 REOZT4 | 40.0 kW | 3 | 67.0 dBA | 1769.0 kg | 293.0 L |
| SDMO JM40UC | 40.0 kW | 3 | 71.0 dBA | 780.0 kg | — |
| Kohler 40 REOZK4 | 40.0 kW | — | 68.0 dBA | 1442.0 kg | 293.0 L |
| Westquip WQ40T4H | 40.0 kW | 1,3,3 | — | 625.0 kg | — |
| Aurora Generators AGi40H | 40.0 kW | — | — | 173.0 kg | 45.0 L |
| SDMO J40U | 40.0 kW | 3 | 72.0 dBA | 820.0 kg | — |
| Generac SD040 | 40.0 kW | Three-Phase | 75.0 dBA | 790.0 kg | 211.0 L |
| Simson-Maxwell SDW55 T6-T2 | 40.0 kW | 1 | — | 762.3 kg | 322.1 L |
| Northern Lights M40C3F | 40.0 kW | 3ph,1ph | — | 680.0 kg | — |
| Caps CP50-TP1 | 40.0 kW | 3 | 65.0 dBA | 986.0 kg | 160.0 L |
| Kohler 40EORZD | 40.0 kW | — | — | — | — |
| Perkins 1103C-33TG2 | 41.0 kW | — | — | — | — |
| Perkins 1103C-33TG3 | 41.0 kW | — | — | — | — |
| Cummins/Onan 4BTAA3.3-G18 | 42.0 kW | — | — | 333.0 kg | — |
| Mitsubishi MDG40 | 42.0 kW | 1-3 switchable | — | — | — |
| Kohler 40REOZK | 42.0 kW | — | — | 787.0 kg | — |
| Kohler 40REOZT | 42.0 kW | — | — | — | — |
| Generac MMG45IF4 | 44.0 kW | 1 or 3 | 66.0 dBA | 1290.0 kg | 379.0 L |
| Emsa E BD XX 0055 | 44.0 kW | — | — | 1113.0 kg | 101.0 L |
| FG Wilson P55-3 | 44.0 kW | 3 | 56.7 dBA | 797.0 kg | 145.0 L |
| FG Wilson P55-1 | 44.0 kW | 3 | — | 863.0 kg | 219.0 L |
| FG Wilson P55-2 | 44.0 kW | 3 | — | 957.0 kg | 219.0 L |
| MTU 4R0113 DS55 | 44.0 kW | 3 | 77.6 dBA | 943.0 kg | — |
| Kubota V2403-M-T-E3B | 44.0 kW | Counterclockwise Viewed on Flywheel | — | 1960.0 kg | — |
| Olympian GEP55-3 | 44.0 kW | 3 | — | 863.0 kg | 219.0 L |
| Morse GCRS-40-40 | 44.5 kW | 3 | — | — | 159.0 L |
Among 40–45 kW Diesel generators in this comparison, the FG Wilson P55-3 is quietest at 56.7 dBA.
Among 40–45 kW Diesel generators in this comparison, the Cummins/Onan DGCB is lightest at 97.0 kg dry weight.
Among 40–45 kW Diesel generators in this comparison, the Generac MMG45IF4 has the largest fuel tank at 379.0 L.
Not every model reports every spec — blanks mean the source document didn't state that figure, not that the value is zero.