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.
- Firman H08051
- Westinghouse WGen20000TFc
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 | Westinghouse WGen20000TFc |
|---|---|---|
| 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: 20000 W |
| Starting watts | 10000 W | Winner: Winner: 28000 W |
| Noise (lower limit) | Winner: Winner: 74 dB | 79 dB |
| Weight | Winner: Winner: 212 lbs | 557 lbs |
| Run time @50% load | Winner: Winner: 12 h | 10.5 h |
| Run time @25% load | Not available | 13 h |
| Fuel tank | 8 gal | 17.17 gal |
| Fuel gauge | Yes | Yes |
| Approx. dimensions (L × W × H) | 30.2 x 27.5 x 26.3 | 38 x 35 x 40.4 |
| Electrical | ||
| Voltage (AC) | 120/240 | 120/240 |
| Voltage (DC) | Not available | Not available |
| GFCI outlets | Yes | Yes |
| Covered outlets | Yes | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | 25 % | 5 % |
| Engine | ||
| Engine | Firman Max-Pro Series OHV 4-stroke, cast iron sleeve | 999 cc OHV V-Twin, cast iron sleeve |
| Alternator | Not available | Not available |
| Starting system | Recoil, Electric | Electric, Remote |
| Warranty | ||
| Warranty | 3 years | 3 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 8000 W | 20000 W |
| Starting watts | 10000 W | 28000 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 | 10.5 h |
| Run time @25% load | Not available | 13 h |
| Propane | Not available | Not available |
| Running watts | 7250 W | 18000 W |
| Starting watts | 9050 W | 25500 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 | 2.5 h |
| Run time @25% load | Not available | 3 h |
| Natural gas | Not available | Not available |
| Running watts | Not available | 16000 W |
| Starting watts | Not available | 22400 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 | false |
| Compliance | CARB, EPA | EPA, ANSI/PGMA G300-2023 |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | Bonded to frame | Bonded Neutral |
| UPC | 840876180518 | 850032657785 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 8000 | 20000 |
| Running Watts (Propane) | 7250 | 18000 |
| Running Watts (Natural Gas) | Not available | 16000 |
| Starting Watts (Gasoline) | 10000 | 28000 |
| Starting Watts (Propane) | 9050 | 25500 |
| Starting Watts (Natural Gas) | Not available | 22400 |
| Runtime @ 50% Load (Gasoline) | 12 | 10.5 |
| Runtime @ 50% Load (Propane) | 5 | 2.5 |
| Runtime @ 25% Load (Gasoline) | Not available | 13 |
| Runtime @ 25% Load (Propane) | Not available | 3 |
| 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) | 2x Duplex 120V 20A (5-20R) GFCI; 1x 120V 30A (L5-30R); 2x 120/240V 30A (L14-30R); 2x 120/240V 50A (14-50R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | OHV 4-stroke | 999 cc OHV V-Twin, cast iron sleeve |
| Engine Displacement | 439 | 999 |
| Cylinder Sleeve | Cast iron | Cast Iron Sleeve |
| Alternator Winding Material | Not available | Copper windings |
| Engine Oil Type | Not available | SAE 10W-30 |
| Runtime & fuel system | ||
| Runtime @ 25% Load (Gasoline) | Not available | 13 |
| Runtime @ 50% Load (Gasoline) | 12 | 10.5 |
| Runtime @ 50% Load (Propane) | 5 | 2.5 |
| Outlets & connections | ||
| Transfer Switch Compatibility | Not available | Yes |
| Controls & display | ||
| Display Type | Not available | VFT Display |
| Idle Control System | Not available | Low Idle Control |
| 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 | Wheels, Handles |
| Starting Components | Recoil, Electric | Electric start, Remote start |
| Fuel Connection Components | Propane hose | natural gas hose with NPT adapter, propane hose |
| Maintenance Components | Not available | Oil Bottle, Oil Funnel, Spark Plug Wrench |
| Documentation | Not available | User Manual |
| 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, battery, and wheel kit |
| Warranty & identification | ||
| Residential Warranty | Not available | 3 Year Limited |
| Commercial Warranty | 3 | 1 Year Limited |
| Part Number | Not available | WGen20000TFc |
| 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 Westinghouse WGen20000TFc is a 20,000-watt tri-fuel generator built for high-demand applications where fuel flexibility matters. Tri-fuel operation means you can run gasoline for peak output, natural gas for stationary backup, or propane for portable fuel options. This wattage class handles whole-house backup, large job sites, and RV power simultaneously without compromise. The tri-fuel design trades simplicity for adaptability, letting you choose the fuel source that matches your situation rather than locking you into one supply chain. |
- Most PowerfulWestinghouse WGen20000TFc20000W running
- QuietestFirman H0805174 dB
- Longest RuntimeFirman H0805112h at 50% load
Where to buy
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Firman H08051
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Westinghouse WGen20000TFc
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