Cummins 4BTA3.9-G2 vs Yuchai YC4D105-D34
The Cummins 4BTA3.9-G2 and Yuchai YC4D105-D34 are both diesel generator engines in a similar power class. Both are rated at roughly 81 kVA. Displacement is 3.9 L versus 4.75 L. The table below compares their full specifications side by side.
| Specification | Cummins 4BTA3.9-G2 | Yuchai YC4D105-D34 |
|---|---|---|
| Headline rating | 81 kVA | 80 kVA |
| Standby (50 Hz) | 65 kWe | 64 kWe |
| Prime (50 Hz) | 52 kWe | 60 kWe |
| Standby (60 Hz) | 75 kWe | — |
| Prime (60 Hz) | 60 kWe | — |
| Displacement | 3.9 L | 4.75 L |
| Configuration | L4 | L4 |
| Cylinders | 4 | 4 |
| Rated speed | 1,500 / 1,800 RPM | 1,500 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | China National Stage III / Unregulated |
| Dry weight | — | — |
| Origin | China | China |
Choosing between Cummins 4BTA3.9-G2 and Yuchai YC4D105-D34
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 4BTA3.9-G2 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.