The Generac GP5500 5939 is part of the generator
test program at Consumer Reports. In our lab tests, generator
models like the GP5500 5939 are rated on multiple criteria, such as those listed below.
Ease of use:
Includes starting, transport (for portables), and helpful features such as fuel shutoff.
How much wattage models delivered and how well they handled surges in power demand over various loads.
Measured at 23 and 50 feet from the generator. We recommend hearing protection for standing close by the unit while it's running.
Features & Specs - Generac GP5500 5939
Claimed output (watts) Maximum wattage for continuous operation, as per the manufacturer.
Claimed output (watts)
Fuel type Gasoline, diesel fuel, propane, or (stationary models only) natural gas.
Weight (lbs.) The generator’s weight, to the nearest pound, when fully fueled. (Propane tanks are separate, and natural-gas models are fueled externally.) Weight for stationary models, which stay where installed, is "NA," for not applicable.
Fuel shutoff Lets you draw gas from the fuel system to keep it from leaking, or from fouling parts if it degrades during storage.
Low-oil shutoff Turns off the engine if the oil level is low, preventing damage.
Electric start Lets you start the engine with a switch or pushbutton rather than a pull cord.
Fuel gauge Indicates how much fuel is in a portable generator's tank.
Excellent generator, especially at this price point. With respect to complaints about noise, this unit actually has an excellent muffler .... Most of the noise is mechanical engine noise, not exhaust noise. Recommendation - after manufacturer's break-in period using traditional 30W engine oil, switch to a high-quality synthetic 10W30 (I used Amsoil ASE). The engine noise difference is amazing - subjectively about 50% less noisy using the synthetic oil!
How long have you owned it:
Yes, I would recommend this to a friend.
By Kim & John
(10 of 11 customers found this review helpful)
An addendum to my 10/4/2012 review entitled Not for use with sensitive electronics<br /><br />One thing I forgot to mention when referreing to Dirty Power put out by this generator (This is rated at 23-28% Total Harmonic Distorion, while the recommendation fo relectronics is 5% max THD): <br /><br />Back in the day when heating control systems were just thermostat controlled switches, how clean or pure the power was did not cause as much of an issue. However, most modern heating systems have electronic controls. Some of these will simply not run on dirty power. If you are relying on this to run your heating system during a power outage, be sure to check if your system will actually run on this. A call to the heating system control manufacturer may be in order, or plug it in and try it out.
How long have you owned it:
No, I would not recommend this to a friend.
from Columbus, OH
(4 of 6 customers found this review helpful)
Needs an outside enclosure
The power goes out when the weather is bad meaning, it's raining or snowing outside. If you place the generator out in the rain or snow you will ruin it. In an attached garage, with the garage doors open, a running generators exhaust will migrate into the home. So the only practical solution is to have an outside enclosure for the generator.