Caterpillar C3.3 vs Doosan DB58
The Caterpillar C3.3 and Doosan DB58 are both diesel generator engines in a similar power class. Both are rated at roughly 65 kVA. Displacement is 3.3 L versus 5.8 L. The table below compares their full specifications side by side.
| Specification | Caterpillar C3.3 | Doosan DB58 |
|---|---|---|
| Headline rating | 65 kVA | 64 kVA |
| Standby (50 Hz) | 52 kWe | 51.3 kWe |
| Prime (50 Hz) | 48 kWe | 48 kWe |
| Standby (60 Hz) | 60 kWe | — |
| Prime (60 Hz) | 55 kWe | — |
| Displacement | 3.3 L | 5.8 L |
| Configuration | L4 | L6 |
| Cylinders | 4 | 6 |
| Rated speed | 1,500 / 1,800 RPM | 1,500 RPM |
| Fuel | Diesel | Diesel |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | Unregulated | U.S. EPA Tier 1 |
| Dry weight | — | — |
| Origin | United States | South Korea |
Choosing between Caterpillar C3.3 and Doosan DB58
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 Caterpillar C3.3 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.