The Generator EngineEncyclopedia

Ford LSG635 vs Generac SG045

The Ford LSG635 and Generac SG045 are both natural gas generator engines in a similar power class. The Generac SG045 is the higher-output unit (56 kVA vs 51 kVA). Displacement is 3.5 L versus 4.43 L. The table below compares their full specifications side by side.

SpecificationFord LSG635Generac SG045
Headline rating51 kVA56 kVA
Standby (50 Hz)
Prime (50 Hz)
Standby (60 Hz)45 kWe
Prime (60 Hz)41 kWe41 kWe
Displacement3.5 L4.43 L
ConfigurationV6L4
Cylinders64
Rated speed1,800 RPM1,800 RPM
FuelNatural GasNatural Gas
CoolingLiquid-CooledLiquid-Cooled
EmissionsU.S. EPA StationaryU.S. EPA Stationary
Dry weight177 kg
OriginUnited StatesUnited States

Choosing between Ford LSG635 and Generac SG045

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 SG045 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.