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Generac SG625 vs Waukesha VGF36GSI/GSID (L36GSI/GSID)

The Generac SG625 and Waukesha VGF36GSI/GSID (L36GSI/GSID) are both natural gas generator engines in a similar power class. Both are rated at roughly 778 kVA. Displacement is 33.9 L versus 36 L. The table below compares their full specifications side by side.

SpecificationGenerac SG625Waukesha VGF36GSI/GSID (L36GSI/GSID)
Headline rating781 kVA775 kVA
Standby (50 Hz)
Prime (50 Hz)
Standby (60 Hz)625 kWe620 kWe
Prime (60 Hz)560 kWe
Displacement33.9 L36 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 Generac SG625 and Waukesha VGF36GSI/GSID (L36GSI/GSID)

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 Generac SG625 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.