Overview#
The Cat C4.4 is an 80-kilowatt diesel generator set that occupies the mid-range of Caterpillar's compact generator lineup. Powered by the Cat C4.4 turbocharged inline-4 engine with 4.4 liters of displacement and direct injection, it delivers enough power for medium commercial facilities, retail centers, and telecommunications infrastructure while maintaining a compact footprint under 2,250 pounds.
With both standby (80 kW) and prime (72 kW) ratings available, the C4.4 serves double duty — emergency backup for commercial buildings and continuous prime power for construction sites or off-grid installations. The 100 kVA standby rating at 0.8 power factor places it in the sweet spot for facilities that need reliable backup without stepping up to Cat's larger six-cylinder platforms.
The 80 kW commercial sweet spot#
80 kW covers a substantial commercial load profile: HVAC systems, lighting, elevators in low-rise buildings, data closets, and essential process equipment. The C4.4's motor starting capability of 311 skVA at 208V means it can handle inrush current from multiple HVAC compressor starts without excessive voltage dip, reducing the need for soft starters or load sequencing in many installations.
The mechanical governor and direct injection system keep the engine straightforward for field service, while the 17.25:1 compression ratio provides reliable cold-start capability. At 73.6 inches long and only 33.1 inches wide, the C4.4 has a notably narrow profile that fits tight equipment rooms and pad-mounted installations where site space is constrained.
Our service experience#
The C4.4 is a workhorse in our commercial accounts across Northern California. We see it most often at medium retail locations, small office parks, and telecom cell sites where 60-100 kW covers the critical load. The turbocharged inline-4 is a proven platform — the same basic engine architecture powers Cat's compact construction equipment — and parts availability is excellent through the Cat dealer network. We recommend quarterly exercise under load and annual fuel system inspection for standby installations, with particular attention to fuel quality on units that sit idle for extended periods.
