Generac GP6500 COsense provides reliable power with carbon monoxide sensor
Whether your priority is emergency power or powering your job site, it's always generator season. With hurricane season on the horizon, our team's construction demands aren't slowing down, and we're taking a deeper look at what the Generac GP6500 COsense portable generator has to offer.
advantage
- COsense monitors carbon monoxide levels and automatically shuts off if levels get too high
- 4 x 120V outlets and 1 x 120/240V outlet
- solid frame construction
- $799 price tag offers excellent value at this power level and CO sensing
shortcoming
- Incorrect positioning will cause the CO sensor to trip when not dangerous (common to all CO induction generators)
- Not recommended for sensitive electronics
recommend
Get your money's worth with the Generac GP6500 COsense Portable Generator. Its 6500-watt operating capacity provides plenty of versatility for emergency power and jobsite power, while its COsense unit prevents carbon monoxide build-up. Of course, there are some great options for other models, but you need to start pumping up the $799 price a lot.
feel the same
The standout feature of this Generac 6500 Watt generator is COsense. It's a sensor that detects carbon monoxide levels, alerts you to dangerous levels and automatically shuts off the engine.

Every year, people who use generators think they can run as long as they have an open door or window, but that's not enough. Even certain areas of the workplace can become gathering points. Unfortunately, this is a mistake with potentially fatal consequences.
With COsense, you get faster detection than typical home CO detectors, allowing for quick engine shutdowns.

Sometimes this can work against you even if you set up your generator in a location where it can run safely. Pay attention to which direction the wind is blowing and make sure the exhaust is blowing away from the sensor and not towards it to avoid unplanned shutdowns.
strength
The Generac GP6500 COsense uses a Generac 389cc overhead valve engine delivering 6500 continuous operating watts. Generac's PowerRush Advanced Technology handles the inrush current, boosting it to a starting 8125 watts.

The big question is what that power means to you. Of course, every situation is different.
If you want an electrician to set up a direct hookup for your house, there is enough power to run most single unit central air units (3000 – 5000 watts) and leave some room for your fridge and a few other things.
In fact, anything that plugs into a standard 120V outlet is fair game. It's just a matter of how many of these items you can use at one time. Even 240V products up to 27 amps will do the job.
Basically, 6500 watts of continuous running power gives you a lot of versatility, but nowhere near what you need from a whole house generator.
Check out this article to learn how to determine your power needs.
run
After "What can I run?" is usually followed by "How long will it run?" when we receive questions about generators. As far as our answer goes, the Generac GP6500 COsense is no different – it depends on what you're running.
At 50 percent capacity (3350 watts), the unit's 6.9 gallon fuel tank will run the engine for about 10 1/2 hours. If you're considering emergency power, that's just under 16 gallons of fuel per day.
If you run more watts you will get less run time, if you run less you will get more run time.
noise level
Technically, there is no standard in the US that we know of for testing generator noise levels. To complicate any test, putting a load on the generator means we have to run some kind of equipment and increase the noise level.
That said, we still ran some tests. We measured 3 feet from the front to capture the brief sound you might hear when starting up. We then measured a safe working distance of 20 feet.
Keep in mind that your alternator probably runs between idle and half throttle most of the time, just picking up speed to handle the inrush current.
3 feet | 20 feet | |
idle | 90 decibels | 76 decibels |
50% throttle | 94 decibels | 81 decibels |
100% throttle | 98 decibels | 89 decibels |
Just for the kick, we ran another test to see how close you can get to 85 decibels at idle — the limit when OSHA hearing protection regulations were in effect. For this model, it's 7 1/2 feet.
connect
Obviously, you can only run the plugs you own. Here are the connections you get on the Generac GP6500 COsense:
- 2 x 120V, 20A 5-20R GFCI duplex (4 outlets total)
- 1 x 120/240V, 30A L14-30R Twist Lock
There aren't any USB or 12V outlets to connect directly to the generator, but that's okay. You typically use these devices inside, while the generator will be outside.

Pro tip: Make sure the extension cord you're using is suitable for the equipment you're running. Check out this article for help choosing the best gauge and length.
transportation
The frame of the generator is made of 1 1/4 inch steel pipe for sufficient rigidity and strength. The 9 1/2" never-flat wheels let you roll easily on most surfaces. While they sink a little on wet ground, they are effective on hard surfaces and firm ground.
The handle mount may seem a bit odd at first. Everything in us wants to mount it upside down based on first impressions. However, when you install it properly, it folds up. Its position means you have to bend slightly to grab the bar, but it puts the unit at a comfortable roll height and angle.
Additional features
- Timer display on control panel helps you track maintenance intervals
- Low oil shutdown prevents major engine damage
- Outlet covers help keep out the elements
- Fuel shutoff valve (we like it metal instead of plastic)

missing features
- Electric start (available on GP6500 without COsense)
- Not recommended for sensitive electronics (THD – Total Harmonic Distortion – more than 5%)
- automatic choke

One concern I have is the choke lever. Its shape and plastic construction make it a risk of breaking. It's easily accessible and still usable, but may require thicker levers or a sturdier design.
price
The Generac GP6500 COsense is attractively priced at $799. Here are a few other models with similar operating power and CO sensors:
- Champion 100593 with CO Shield (6250 running watts): $749
- Generac GP6500 with COsense 7680: $799
- Ryobi RY906500S with CO Shutdown: $799
- DeWalt DXGNR6500 with CO protection: $899
If you're looking for a CARB-compliant model, check out the $849 GP6500 7683. It's the same generator, but California friendly.
the bottom line
Get your money's worth with the Generac GP6500 COsense Portable Generator. Its 6500-watt operating capacity provides plenty of versatility for emergency power and jobsite power, while its COsense unit prevents carbon monoxide build-up. Of course, there are some great options for other models, but you need to start pumping up the $799 price a lot.
Generac Portable Generator Specifications
- Model: Generac GP6500
- Operating power: 6500 W
- Starting wattage: 8125 W
- AC voltage: 120/240 VAC
- AC Frequency: 60 Hz
- 120/240 VAC Amperage: 54.2/27.1
- Engine Displacement: 389cc
- Length: 27.2 inches
- Width: 27 inches
- Height: 26.5 inches
- Weight: 172 lbs.
- Warranty: 3 Year Residential/1 Year Commercial
- Price: $799
Check out more Generac products by visiting their website.