Cat 5,500W Gas Generator Review

Summary

The Cat RP5500 is a gasoline powered generator built for serious mid-range power delivery. With 5,500 running watts and 6,875 starting watts, this unit can handle simultaneous loads that go well beyond basic electronics. Think a refrigerator, a sump pump, a window AC unit, and several lights running at the same time. That starting watt surge of 6,875 watts also gives it the headroom to kick on motor driven appliances that demand a spike of power at startup, like a well pump or a large shop tool.

Cat brings its heavy equipment reputation into the portable generator space with this model, and the RP5500 reflects that industrial DNA. This is not a lightweight camping companion. It is a workhorse geared toward homeowners who need real backup power during outages and job site operators who need to run corded tools without worrying about capacity. The 7.9 gallon fuel tank and solid runtime numbers reinforce that this generator is built for sustained operation, not just quick bursts.

Power & Runtime

Running on gasoline, the RP5500 draws from the most widely accessible fuel source available, which matters during emergencies when specialty fuels can be hard to find. At 50% load, the generator runs for 15 hours on a single 7.9 gallon tank. That translates to roughly half a gallon per hour at moderate demand, meaning a homeowner running essential circuits overnight can sleep through the night without getting up to refuel. For a full day of operation at moderate draw, one refueling stop around midday keeps everything running.

Because the unit includes automatic voltage regulation, the power output stays clean and stable even as the load fluctuates. AVR actively corrects voltage sags and spikes, which is critical when running sensitive electronics like laptops, LED TVs, or phone chargers alongside heavier loads. Dirty power destroys circuit boards. AVR prevents that. No noise level data is listed for this model, so prospective buyers should plan to hear it running at a typical open frame generator volume and place it a reasonable distance from living or sleeping areas.

Outlets

The RP5500 comes with four NEMA 5-20R outlets, each delivering 120V at 20 amps. These are standard three prong household receptacles, the same type found on every wall in a typical American home. That means you can plug in extension cords, power strips, refrigerators, fans, lamps, and most corded power tools without any adapters. Having four of them available at once allows users to distribute loads across multiple circuits rather than daisy chaining everything off a single outlet, which reduces the risk of tripping a breaker.

The single L14-30R twist lock outlet delivers 120/240V at 30 amps. This is the connection point for heavier applications. A transfer switch hookup runs through this outlet, giving homeowners the ability to feed power directly into their home's breaker panel during an outage. It also supports 240V equipment like certain welders or large stationary tools. The twist lock design prevents accidental disconnection under vibration or load, which is a practical safety advantage on active job sites.

Portability

At 178 pounds, the Cat RP5500 is a heavy machine. Moving it solo is not realistic for most people without wheels or a second pair of hands. Loading it into a truck bed or hauling it down basement stairs requires planning and physical effort. This weight is a genuine drawback for anyone who expects to relocate the generator frequently or store it in tight spaces that require lifting.

The physical footprint of 32.9 by 27.4 by 24.7 inches means this generator occupies roughly the same floor space as a large rolling toolbox. It will fit in a truck bed or a garage corner without much trouble, but it is not something you tuck into a closet. For storage, users should account for clearance around the unit for ventilation and easy access to the fuel cap and outlets. The dimensions are manageable for stationary or semi-stationary use, but anyone planning to transport this unit regularly should factor in the weight as a real logistical consideration.

Features

The recoil starting system is a manual pull start, which means there are no batteries to maintain or electrical components that can fail in storage. Pull the cord and the engine fires. It is simple and reliable, though it does require some physical effort, and cold weather starts may take a few extra pulls. Users who prefer push button convenience will find this less appealing, but the tradeoff is zero dependency on a charged battery.

Safety runs deep on this unit. All outlets are covered, protecting receptacles from rain, dust, and debris when not in use. The GFCI protected outlets monitor for ground faults in real time and cut power instantly if a dangerous current leak is detected, which is especially important when operating outdoors on wet ground. A built in spark arrestor makes the RP5500 safe to use in wooded or dry brush areas where an errant spark could start a fire, and it meets both CARB and EPA compliance standards, so it is legal to purchase and operate in all 50 states including California. The fuel gauge lets users check remaining fuel at a glance without opening the tank cap, a small but valuable convenience during extended runs. Cat backs the RP5500 with a 2 year warranty, covering defects in materials and workmanship for a defined ownership window.

Recommended Audiences

• Shoppers who prefer gasoline powered generators for their fuel availability and straightforward operation
• Homeowners needing whole house or job site backup power capable of running multiple heavy appliances and tools simultaneously
• Noise sensitive users or those in campground environments who should note that no decibel rating is listed and may want to confirm sound levels before purchasing
• DIY enthusiasts and hobbyists needing reliable portable power for workshops, outdoor projects, and occasional emergency use