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.
- Generac #8251 GP2500i
- Genmax GM3300i
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 | Generac #8251 GP2500i | Genmax GM3300i |
|---|---|---|
| General | ||
| Product type | Generator | Generator |
| Fuel | Gasoline | Gasoline |
| Inverter | Yes | Yes |
| Parallel capable | Yes | Yes |
| RV ready | No | Yes |
| Running watts | 2200 W | Winner: Winner: 3000 W |
| Starting watts | 2500 W | Winner: Winner: 3300 W |
| Noise (lower limit) | 0 dB | Winner: Winner: 62 dB |
| Weight | 48 lbs | Winner: Winner: 47.4 lbs |
| Run time @50% load | Winner: Winner: 4.5 h | Winner: Winner: 4.5 h |
| Run time @25% load | 8 h | 6 h |
| Fuel tank | 1 gal | 1 gal |
| Fuel gauge | No | No |
| Approx. dimensions (L × W × H) | 19.7 x 11.4 x 17.9 | 18.9 x 11.4 x 17.3 |
| Electrical | ||
| Voltage (AC) | 120 | 120 |
| Voltage (DC) | 12 | 5 |
| GFCI outlets | No | No |
| Covered outlets | Yes | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | Not available | Not available |
| Engine | ||
| Engine | 98 cc OHV 4-stroke | 145 cc Dinking OHV 4-stroke |
| Alternator | Not available | Not available |
| Starting system | Recoil | Recoil |
| Warranty | ||
| Warranty | 3 years | 1 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 2200 W | 3000 W |
| Starting watts | 2500 W | 3300 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 | 4.5 h | 4.5 h |
| Run time @25% load | 8 h | 6 h |
| Other | ||
| Data center | Not available | Not available |
| Indicators | true | true |
| Compliance | EPA, ANSI/PGMA G300-2023 | EPA, ANSI/PGMA G300-2023 |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | Not available | Floating |
| UPC | 696471003946 | 768494056087 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 2200 | 3000 |
| Starting Watts (Gasoline) | 2500 | 3300 |
| Runtime @ 50% Load (Gasoline) | 4.5 | 4.5 |
| Runtime @ 25% Load (Gasoline) | 8 | 6 |
| AC Outlet Types | 1x Duplex 120V 20A (5-20R) | 1x Duplex 120V 20A (5-20R) 1x 120V 30A (TT-30R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | 98 cc OHV 4-stroke | Dinking OHV 4-stroke |
| Engine Displacement | 98 | 145 |
| Engine Oil Type | 10W-30 | 10W-30 |
| Runtime & fuel system | ||
| Runtime @ 25% Load (Gasoline) | 8 | 6 |
| Runtime @ 50% Load (Gasoline) | 4.5 | 4.5 |
| Safety & compliance | ||
| Overload Protection System | Low oil and overload protection | Low oil and overload protection, CO monitoring |
| Low Oil Protection | Yes | Yes |
| Carbon Monoxide Monitoring | Yes | Yes |
| Included equipment | ||
| Starting Components | Recoil | Not available |
| Included Accessories | Oil, funnel, tool kit, and battery charging cables | Funnel and tool kit |
| Warranty & identification | ||
| Commercial Warranty | 3 | Not available |
| Part Number | 82512 | GE-3300A |
| Additional specs | ||
| Summary | The Generac GP2500i is a 2200-watt inverter generator built for portable backup power and recreational use. At 48 pounds, it moves easily between campsites, job sites, and emergency situations. The inverter technology means laptops, phones, and sensitive tools run safely because the power output stays stable. This unit runs on gasoline and delivers 2500 starting watts, so it can handle the initial surge when motors kick on. | The Genmax GM3300i is a 3000-watt gasoline inverter generator built for portability and clean power. At 47.4 lbs, it moves easily between campsites, job sites, and homes. The 3300-watt peak output handles startup surges on power tools and appliances, while the inverter technology protects laptops and phones from voltage spikes. |
- Most PowerfulGenmax GM3300i3000W running
- QuietestGenmax GM3300i62 dB
- Longest RuntimeGenerac #8251 GP2500i4.5h at 50% load
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Generac #8251 GP2500i
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Genmax GM3300i
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