The Generator EngineEncyclopedia

Cummins C650N6 vs Generac SG625

The Cummins C650N6 and Generac SG625 are both natural gas generator engines in a similar power class. Both are rated at roughly 797 kVA. Displacement is 50.3 L versus 33.9 L. The table below compares their full specifications side by side.

SpecificationCummins C650N6Generac SG625
Headline rating813 kVA781 kVA
Standby (50 Hz)
Prime (50 Hz)
Standby (60 Hz)650 kWe625 kWe
Prime (60 Hz)
Displacement50.3 L33.9 L
ConfigurationV16V12
Cylinders1612
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 C650N6 and Generac SG625

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 C650N6 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.