Compare Generators Side-by-Side
Select up to 4 generators to compare specs, power output, noise levels, runtime and more. Your compare URL is shareable.
- Cummins Onan P2500i
- Genmax GM3500iAED
Quick charts
Each chart uses its own Y-axis scale (so numbers are comparable within a chart).
Running watts
W
Starting watts
W
Noise
dB
Runtime @50%
h
Running watts by fuel
Shows how output changes across gasoline/propane/natural gas (when available).
| Specification | Cummins Onan P2500i | Genmax GM3500iAED |
|---|---|---|
| General | ||
| Product type | Generator | Generator |
| Fuel | Gasoline | Dual-Fuel |
| Inverter | Yes | Yes |
| Parallel capable | Yes | Yes |
| RV ready | No | No |
| Running watts | 2200 W | Winner: Winner: 3200 W |
| Starting watts | 2500 W | Winner: Winner: 3500 W |
| Noise (lower limit) | Winner: Winner: 52 dB | 62 dB |
| Weight | Winner: Winner: 48 lbs | 56.2 lbs |
| Run time @50% load | Winner: Winner: 8 h | Not available |
| Run time @25% load | 10 h | 9 h |
| Fuel tank | 1 gal | 1.7 gal |
| Fuel gauge | Yes | Yes |
| Approx. dimensions (L × W × H) | 19.8 x 10.5 x 18.3 | 20.9 x 12.2 x 19.7 |
| Electrical | ||
| Voltage (AC) | 120 | 120 |
| Voltage (DC) | 12 | 5 |
| GFCI outlets | No | No |
| Covered outlets | Yes | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | <3% % | ≤3% % |
| Engine | ||
| Engine | 98 cc Ducar OHV 4-stroke engine | 145 cc OHV 4-stroke |
| Alternator | Not available | Not available |
| Starting system | Recoil | Recoil, Electric, Remote |
| Warranty | ||
| Warranty | 3 years | 1 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 2200 W | 3200 W |
| Starting watts | 2500 W | 3500 W |
| Running amps (120V) | Not available | Not available |
| Running amps (240V) | Not available | Not available |
| Peak amps (120V) | Not available | Not available |
| Peak amps (240V) | Not available | Not available |
| Run time @50% load | 8 h | Not available |
| Run time @25% load | 10 h | 8 h |
| Propane | Not available | Not available |
| Running watts | Not available | 2800 W |
| Starting watts | Not available | 3100 W |
| Running amps (120V) | Not available | Not available |
| Running amps (240V) | Not available | Not available |
| Peak amps (120V) | Not available | Not available |
| Peak amps (240V) | Not available | Not available |
| Run time @50% load | Not available | Not available |
| Run time @25% load | Not available | 16 h |
| Other | ||
| Data center | Not available | Not available |
| Indicators | true | true |
| Compliance | CARB, EPA | EPA, ANSI/PGMA G300-2023 |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | Floating | true |
| UPC | 690781007918 | 713424639021 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 2200 | 3200 |
| Running Watts (Propane) | Not available | 2800 |
| Starting Watts (Gasoline) | 2500 | 3500 |
| Starting Watts (Propane) | Not available | 3100 |
| Runtime @ 50% Load (Gasoline) | 8 | Not available |
| Runtime @ 25% Load (Gasoline) | 10 | 8 |
| Runtime @ 25% Load (Propane) | Not available | 16 |
| AC Outlet Types | 1x Duplex 120V 20A (5-20R) | 1x Duplex 120V 20A (5-20R) 1x 120V 30A (L5-30R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | Ducar OHV 4-stroke | OHV 4-stroke |
| Engine Displacement | 98 | 145 |
| Engine Oil Type | SAE 10W30 | 10W-30 |
| Runtime & fuel system | ||
| Runtime @ 25% Load (Gasoline) | 10 | 8 |
| Runtime @ 50% Load (Gasoline) | 8 | Not available |
| Safety & compliance | ||
| Overload Protection System | Low oil and overload protection | Not available |
| Low Oil Protection | Yes | Yes |
| Carbon Monoxide Monitoring | No | Yes |
| Included equipment | ||
| Included Accessories | Oil, funnel, and tool kit | Funnel, tool kit, key fob, propane hose, RV adapter, and battery |
| Additional specs | ||
| Summary | The Cummins Onan P2500i is a 2200-watt inverter generator built for users who need portable power without sacrificing runtime or noise control. At 48 pounds and measuring 19.8 by 10.5 by 18.3 inches, this unit bridges the gap between true portability and practical capacity. It can run a microwave, small refrigerator, or circular saw continuously, making it suitable for camping trips, job sites, tailgating, and emergency backup. The 1-gallon fuel tank delivers 10 hours at 25 percent load and 8 hours at 50 percent load, meaning most users refuel once per day rather than multiple times.
The inverter topology produces clean power with less than 3 percent THD, which protects laptops, phone chargers, and sensitive electronics from voltage spikes. Cummins backs this unit with a 3-year warranty, longer than the 2.4-year average for comparable inverter generators. The 52 dBA noise level sits between a normal conversation and light traffic, allowing operation in noise-restricted campgrounds and residential neighborhoods without drawing complaints. | The Genmax GM3500iAED is a 3,200-watt dual-fuel inverter generator that runs on gasoline or propane. At 56.2 lbs, it handles essential household loads like refrigerators and small power tools while remaining portable enough for camping or job sites. The 62 dB noise level keeps it residential-friendly. |
- Most PowerfulGenmax GM3500iAED3200W running
- QuietestCummins Onan P2500i52 dB
- Longest RuntimeCummins Onan P2500i8h at 50% load
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Cummins Onan P2500i
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