Caterpillar CG18 vs Mesa GX22
The Caterpillar CG18 and Mesa GX22 are both natural gas generator engines in a similar power class. Both are rated at roughly 612 kVA. Displacement is 18.1 L versus 21.9 L. The table below compares their full specifications side by side.
| Specification | Caterpillar CG18 | Mesa GX22 |
|---|---|---|
| Headline rating | 625 kVA | 598 kVA |
| Standby (50 Hz) | — | 478 kWe |
| Prime (50 Hz) | — | — |
| Standby (60 Hz) | 500 kWe | 540 kWe |
| Prime (60 Hz) | — | 491 kWe |
| Displacement | 18.1 L | 21.9 L |
| Configuration | L6 | V12 |
| Cylinders | 6 | 12 |
| Rated speed | 1,800 RPM | 1,500 / 1,800 RPM |
| Fuel | Natural Gas | Natural Gas |
| Cooling | Liquid-Cooled | Liquid-Cooled |
| Emissions | U.S. EPA Stationary | U.S. EPA Stationary |
| Dry weight | — | — |
| Origin | United States | United States |
Choosing between Caterpillar CG18 and Mesa GX22
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 CG18 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.