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Select up to 4 generators to compare specs, power output, noise levels, runtime and more. Your compare URL is shareable.
- Firman H08051
- Genmax GM15000ET
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 | Firman H08051 | Genmax GM15000ET |
|---|---|---|
| General | ||
| Product type | Generator | Generator |
| Fuel | Dual-Fuel | Tri-Fuel |
| Inverter | No | No |
| Parallel capable | No | No |
| RV ready | Yes | Yes |
| Running watts | 8000 W | Winner: Winner: 13000 W |
| Starting watts | 10000 W | Winner: Winner: 15000 W |
| Noise (lower limit) | Winner: Winner: 74 dB | 76 dB |
| Weight | Winner: Winner: 212 lbs | 242 lbs |
| Run time @50% load | Winner: Winner: 12 h | 11 h |
| Run time @25% load | Not available | Not available |
| Fuel tank | 8 gal | 10.5 gal |
| Fuel gauge | Yes | Yes |
| Approx. dimensions (L × W × H) | 30.2 x 27.5 x 26.3 | 28 x 31.6 x 28.7 |
| Electrical | ||
| Voltage (AC) | 120/240 | 120/240 |
| Voltage (DC) | Not available | 12 |
| GFCI outlets | Yes | No |
| Covered outlets | Yes | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | 25 % | 23 % |
| Engine | ||
| Engine | Firman Max-Pro Series OHV 4-stroke, cast iron sleeve | 520 cc OHV 4-stroke |
| Alternator | Not available | Not available |
| Starting system | Recoil, Electric | Recoil, Electric, Remote |
| Warranty | ||
| Warranty | 3 years | 1 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 8000 W | 11000 W |
| Starting watts | 10000 W | 15000 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 | 12 h | 11 h |
| Run time @25% load | Not available | Not available |
| Propane | Not available | Not available |
| Running watts | 7250 W | 13000 W |
| Starting watts | 9050 W | 13000 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 | 5 h | Not available |
| Run time @25% load | Not available | Not available |
| Natural gas | Not available | Not available |
| Running watts | Not available | 12000 W |
| Starting watts | Not available | 12000 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 | Not available |
| Other | ||
| Data center | Not available | Not available |
| Indicators | false | true |
| Compliance | CARB, EPA | EPA, ANSI/PGMA G300-2023 |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | Bonded to frame | Floating |
| UPC | 840876180518 | 760790901382 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 8000 | 11000 |
| Running Watts (Propane) | 7250 | 13000 |
| Running Watts (Natural Gas) | Not available | 12000 |
| Starting Watts (Gasoline) | 10000 | 15000 |
| Starting Watts (Propane) | 9050 | 13000 |
| Starting Watts (Natural Gas) | Not available | 12000 |
| Runtime @ 50% Load (Gasoline) | 12 | 11 |
| Runtime @ 50% Load (Propane) | 5 | Not available |
| AC Outlet Types | 1x Duplex 120V 20A (5-20R); 1x 120V 30A (L5-30R); 1x 120/240V 30A (L14-30R); 1x 120/240V 50A (14-50R) | AC outlets3x Duplex 120V 20A (5-20R)1x 120/240V 30A (L14-30R)1x 120/240V 50A (14-50R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | OHV 4-stroke | OHV 4-stroke |
| Engine Displacement | 439 | 520 |
| Cylinder Sleeve | Cast iron | Not available |
| Engine Oil Type | Not available | SAE 10W/30 |
| Runtime & fuel system | ||
| Runtime @ 50% Load (Gasoline) | 12 | 11 |
| Runtime @ 50% Load (Propane) | 5 | Not available |
| Safety & compliance | ||
| Overload Protection System | Low oil and overload protection | Low oil and overload protection |
| Low Oil Protection | Yes | Yes |
| Carbon Monoxide Monitoring | No | Yes |
| Included equipment | ||
| Mobility Components | Wheel kit | Not available |
| Starting Components | Recoil, Electric | Recoil starter; Electric starter; Remote starter |
| Fuel Connection Components | Propane hose | Not available |
| Included Accessories | Oil, funnel, tool kit, propane hose, battery, and wheel kit | Oil, funnel, tool kit, key fob, battery charger, natural gas hose with NPT adapter, propane hose, cover, neutral bonding plug, battery, and wheel kit |
| Warranty & identification | ||
| Commercial Warranty | 3 | 1 |
| Additional specs | ||
| Summary | The Firman H08051 is an 8,000-watt dual-fuel generator built to power job sites, homes during outages, and RV setups. Running on gasoline, it delivers 8,000 watts continuously and 10,000 watts at startup, enough to run a refrigerator, microwave, and multiple power tools at once. Switch to propane and the output drops to 7,250 watts running and 9,050 watts starting, a trade-off for fuel flexibility and longer shelf life. The 439cc cast-iron engine is engineered for durability in commercial and residential use. At 212 pounds, this is a stationary or semi-portable unit, not a grab-and-go machine. | The Genmax GM15000ET is a 13,000-watt tri-fuel generator built for serious power demands. With 13,000 running watts and 15,000 starting watts, this unit can handle whole-house backup scenarios, including central air conditioning, refrigerators, well pumps, and multiple circuits running simultaneously. Because it runs on gasoline, propane, or natural gas, owners gain real flexibility during emergencies when one fuel source might be unavailable or during extended outages when tapping into a home natural gas line eliminates refueling trips entirely. |
- Most PowerfulGenmax GM15000ET13000W running
- QuietestFirman H0805174 dB
- Longest RuntimeFirman H0805112h at 50% load
Where to buy
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Firman H08051
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Genmax GM15000ET
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