Haifeng Machinery

PSI 5.7L T vs Weichai WP4D77E300NG

The PSI 5.7L T and Weichai WP4D77E300NG are both natural gas generator engines in a similar power class. The Weichai WP4D77E300NG is the higher-output unit (86 kVA vs 81 kVA). Displacement is 5.74 L versus 4.5 L. The table below compares their full specifications side by side.

SpecificationPSI 5.7L TWeichai WP4D77E300NG
Headline rating81 kVA86 kVA
Standby (50 Hz)65 kWe69 kWe
Prime (50 Hz)—60 kWe
Standby (60 Hz)80 kWe69 kWe
Prime (60 Hz)—63 kWe
Displacement5.74 L4.5 L
ConfigurationV8L4
Cylinders84
Rated speed1,500 / 1,800 RPM1,500 / 1,800 RPM
FuelNatural GasNatural Gas
CoolingLiquid-CooledLiquid-Cooled
EmissionsU.S. EPA StationaryUnregulated
Dry weight196 kg—
OriginUnited StatesChina

Choosing between PSI 5.7L T and Weichai WP4D77E300NG

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 Weichai WP4D77E300NG has the higher headline kVA rating in this pair, but site conditions and duty cycle can still change the final recommendation.