The Generator EngineEncyclopedia

Generac SG275 vs PSI 18L

The Generac SG275 and PSI 18L are both natural gas generator engines in a similar power class. Both are rated at roughly 341 kVA. Displacement is 14.2 L versus 18.3 L. The table below compares their full specifications side by side.

SpecificationGenerac SG275PSI 18L
Headline rating344 kVA338 kVA
Standby (50 Hz)270 kWe
Prime (50 Hz)
Standby (60 Hz)275 kWe350 kWe
Prime (60 Hz)248 kWe
Displacement14.2 L18.3 L
ConfigurationL6V10
Cylinders610
Rated speed1,800 RPM1,500 / 1,800 RPM
FuelNatural GasNatural Gas
CoolingLiquid-CooledLiquid-Cooled
EmissionsU.S. EPA StationaryU.S. EPA Stationary
Dry weight
OriginUnited StatesUnited States

Choosing between Generac SG275 and PSI 18L

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 SG275 has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.