The Generator EngineEncyclopedia

Cummins GTA28 vs Generac SG500

The Cummins GTA28 and Generac SG500 are both natural gas generator engines in a similar power class. Both are rated at roughly 625 kVA. Displacement is 28 L versus 25.8 L. The table below compares their full specifications side by side.

SpecificationCummins GTA28Generac SG500
Headline rating625 kVA625 kVA
Standby (50 Hz)
Prime (50 Hz)
Standby (60 Hz)500 kWe500 kWe
Prime (60 Hz)455 kWe
Displacement28 L25.8 L
ConfigurationV12V12
Cylinders1212
Rated speed1,800 RPM1,800 RPM
FuelNatural GasNatural Gas
CoolingLiquid-CooledLiquid-Cooled
EmissionsU.S. EPA StationaryUnregulated
Dry weight
OriginUnited StatesUnited States

Choosing between Cummins GTA28 and Generac SG500

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.