The Generator EngineEncyclopedia

Cummins GTA855E vs Generac SG250

The Cummins GTA855E and Generac SG250 are both natural gas generator engines in a similar power class. Both are rated at roughly 313 kVA. Displacement is 14 L versus 14.2 L. The table below compares their full specifications side by side.

SpecificationCummins GTA855EGenerac SG250
Headline rating313 kVA313 kVA
Standby (50 Hz)
Prime (50 Hz)
Standby (60 Hz)250 kWe
Prime (60 Hz)250 kWe225 kWe
Displacement14 L14.2 L
ConfigurationL6L6
Cylinders66
Rated speed1,800 RPM1,800 RPM
FuelNatural GasNatural Gas
CoolingLiquid-CooledLiquid-Cooled
EmissionsU.S. EPA StationaryU.S. EPA Stationary
Dry weight
OriginUnited StatesUnited States

Choosing between Cummins GTA855E and Generac SG250

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.