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 WH03662OF
- Powerhorse s10500id
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 WH03662OF | Powerhorse s10500id |
|---|---|---|
| General | ||
| Product type | Generator | Generator |
| Fuel | Dual-Fuel | Dual-Fuel |
| Inverter | Yes | Yes |
| Parallel capable | Yes | Yes |
| RV ready | Yes | No |
| Running watts | 3650 W | Winner: Winner: 8300 W |
| Starting watts | 4500 W | Winner: Winner: 10500 W |
| Noise (lower limit) | 69 dB | Winner: Winner: 62 dB |
| Weight | Winner: Winner: 119 lbs | 209.5 lbs |
| Run time @50% load | Not available | Winner: Winner: 12 h |
| Run time @25% load | 25 h | Not available |
| Fuel tank | 6 gal | 7.13 gal |
| Fuel gauge | Yes | Yes |
| Approx. dimensions (L × W × H) | 24.5 x 24.1 x 23 | 30 x 26.3 x 28.8 |
| Electrical | ||
| Voltage (AC) | 120 | 120/240V |
| Voltage (DC) | 12 | 5V |
| GFCI outlets | No | Yes |
| Covered outlets | Yes | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | <3% % | <3% % |
| Engine | ||
| Engine | 208 cc OHV 4-stroke, cast iron sleeve | 457 cc OHV 4-stroke |
| Alternator | Not available | Not available |
| Starting system | Recoil, Electric | Recoil, Electric, Remote |
| Warranty | ||
| Warranty | 3 years | 2 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 3650 W | 8300 W |
| Starting watts | 4500 W | 10500 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 | 12 h |
| Run time @25% load | 25 h | Not available |
| Propane | Not available | Not available |
| Running watts | 3300 W | 7500 W |
| Starting watts | 4100 W | 9450 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 | 6 h |
| Run time @25% load | 19 h | Not available |
| Other | ||
| Data center | Not available | Not available |
| Indicators | true | true |
| Compliance | CARB, EPA, ANSI/PGMA G300-2023 | EPA, ANSI/PGMA G300-2023 |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | Floating | true |
| UPC | 840876136621 | 840321764003 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 3650 | 8300 |
| Running Watts (Propane) | 3300 | 7500 |
| Starting Watts (Gasoline) | 4500 | 10500 |
| Starting Watts (Propane) | 4100 | 9450 |
| Runtime @ 50% Load (Gasoline) | Not available | 12 |
| Runtime @ 50% Load (Propane) | Not available | 6 |
| Runtime @ 25% Load (Gasoline) | 25 | Not available |
| Runtime @ 25% Load (Propane) | 19 | Not available |
| AC Outlet Types | 1x Duplex 120V 20A (5-20R); 1x 120V 30A (L5-30R); 1x 120V 50A (14-50R) | 1x Duplex 120V 20A (L5-20R) GFCI; 1x 120/240V 30A (L14-30R); 1x 120/240V 50A (14-50R); 1x 120/240V 50A (10-50R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | OHV 4-stroke | OHV 4-stroke |
| Engine Displacement | 208 | 457 |
| Runtime & fuel system | ||
| Runtime @ 25% Load (Gasoline) | 25 | Not available |
| Runtime @ 50% Load (Gasoline) | Not available | 12 |
| Runtime @ 50% Load (Propane) | Not available | 6 |
| Safety & compliance | ||
| Overload Protection System | Not available | Low oil and overload protection |
| Low Oil Protection | Yes | Yes |
| Carbon Monoxide Monitoring | Yes | Yes |
| Included equipment | ||
| Starting Components | Not available | Recoil, Electric, Remote |
| Included Accessories | Oil, funnel, tool kit, propane hose, RV adapter, battery charging cables, battery, and wheel kit | Funnel, tool kit, key fob, propane hose, and battery |
| Warranty & identification | ||
| Commercial Warranty | 3 | Not available |
| Additional specs | ||
| Summary | The Firman WH03662OF is a 3,650-watt dual-fuel inverter generator built for both home backup and job site work. On gasoline, it delivers 4,500 starting watts and 3,650 running watts. On propane, output drops to 4,100 starting and 3,300 running watts. This wattage range powers most household appliances, mid-size power tools, and multiple devices simultaneously. The dual-fuel option gives users flexibility during fuel shortages or when propane's longer shelf life matters.
Because the WH03662OF runs at 69 dBA, placement within 20 to 30 feet of living spaces remains practical for residential use. The inverter produces less than 3% THD, which protects laptops, TVs, and other sensitive electronics from voltage spikes. A 6-gallon tank delivers 25 hours of runtime at 25% load on gasoline and 19 hours on propane. At 50% load, runtime drops to zero hours, meaning users refuel frequently under moderate-to-heavy demand. | The Powerhorse s10500id is a dual-fuel inverter generator delivering 10,500 surge watts and 8,300 rated watts, suitable for emergency home backup, RVs, and worksites. |
- Most PowerfulPowerhorse s10500id8300W running
- QuietestPowerhorse s10500id62 dB
- Longest RuntimePowerhorse s10500id12h at 50% load
Where to buy
Prices can change. We update these automatically.
Firman WH03662OF
Store links
No links yet.
Powerhorse s10500id
Store links
No links yet.
Disclosure: Some links may be affiliate links. Specs and comparisons are never hidden.