Cummins QSB3.9-G35 vs John Deere 4045TF285
The Cummins QSB3.9-G35 and John Deere 4045TF285 are both diesel generator engines in a similar power class. Both are rated at roughly 79 kVA. Displacement is 3.9 L versus 4.5 L. The table below compares their full specifications side by side.
| Specification | Cummins QSB3.9-G35 | John Deere 4045TF285 |
|---|---|---|
| Headline rating | 79 kVA | 78 kVA |
| Standby (50 Hz) | 63 kWe | — |
| Prime (50 Hz) | 50 kWe | — |
| Standby (60 Hz) | — | 62 kWe |
| Prime (60 Hz) | — | 56 kWe |
| Displacement | 3.9 L | 4.5 L |
| Configuration | L4 | L4 |
| Cylinders | 4 | 4 |
| Rated speed | 1,500 RPM | 1,800 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | U.S. EPA Tier 3 |
| Dry weight | — | — |
| Origin | China | United States |
Choosing between Cummins QSB3.9-G35 and John Deere 4045TF285
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 Cummins QSB3.9-G35 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.