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.
- DuroStar DS4000S
- Firman W03386
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 | DuroStar DS4000S | Firman W03386 |
|---|---|---|
| General | ||
| Product type | Generator | Generator |
| Fuel | Gasoline | Gasoline |
| Inverter | No | Yes |
| Parallel capable | No | Yes |
| RV ready | No | Yes |
| Running watts | Winner: Winner: 3300 W | Winner: Winner: 3300 W |
| Starting watts | Winner: Winner: 4000 W | 3650 W |
| Noise (lower limit) | 69 dB | Winner: Winner: 58 dB |
| Weight | 92 lbs | Winner: Winner: 91 lbs |
| Run time @50% load | Winner: Winner: 12 h | Not available |
| Run time @25% load | 26 h | 9 h |
| Fuel tank | 4 gal | 1.8 gal |
| Fuel gauge | Yes | No |
| Approx. dimensions (L × W × H) | 23 x 18 x 17.5 | 23.2 x 17.8 x 17.9 |
| Electrical | ||
| Voltage (AC) | 120 | 120 |
| Voltage (DC) | Not available | 12 |
| GFCI outlets | No | No |
| Covered outlets | No | Yes |
| Automatic Voltage Regulation | Yes | Yes |
| THD | Not available | <3% % |
| Engine | ||
| Engine | DuroStar OHV 4-stroke | 193 cc OHV 4-stroke, cast iron sleeve. |
| Alternator | Not available | Not available |
| Starting system | Recoil | Recoil, Electric, Remote |
| Warranty | ||
| Warranty | 3 years | 3 years |
| Power by fuel | ||
| Gasoline | Not available | Not available |
| Running watts | 3300 W | 3300 W |
| Starting watts | 4000 W | 3650 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 | Not available |
| Run time @25% load | 26 h | 9 h |
| Other | ||
| Data center | Not available | Not available |
| Indicators | true | true |
| Compliance | CARB, EPA | CARB, EPA |
| Security | Not available | Not available |
| Spark arrestor | Yes | Yes |
| Neutral | Floating | Floating |
| UPC | 811640011840 | 840876133866 |
| Core / High-priority specs | ||
| Running Watts (Gasoline) | 3300 | 3300 |
| Starting Watts (Gasoline) | 4000 | 3650 |
| Runtime @ 50% Load (Gasoline) | 12 | Not available |
| Runtime @ 25% Load (Gasoline) | 26 | 9 |
| AC Outlet Types | 1x Duplex 120V 20A (5-20R); 1x 120V 30A (L5-30R) | 1x Duplex 120V 20A (5-20R); 1x 120V 30A (TT-30R) |
| Electrical & power | ||
| Frequency | 60 | 60 |
| Engine & construction | ||
| Engine Type | OHV 4-stroke | OHV 4-stroke |
| Engine Displacement | 208 | 193 |
| Cylinder Sleeve | Not available | cast iron sleeve |
| Engine Oil Type | 10W-30 | See 'Add Engine Oil' Section |
| Runtime & fuel system | ||
| Runtime @ 25% Load (Gasoline) | 26 | 9 |
| Runtime @ 50% Load (Gasoline) | 12 | 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 | ||
| Included Accessories | Funnel and tool kit | Oil, funnel, tool kit, key fob, battery charger, battery charging cables, and battery |
| Warranty & identification | ||
| Commercial Warranty | Not available | 3 |
| Additional specs | ||
| Summary | The DuroStar DS4000S is a 3,300-watt gasoline generator built around a DuroStar OHV 4-stroke engine that delivers 4,000 peak watts for startup surges. This wattage range powers essential household appliances, power tools, and small job site equipment simultaneously. A single person can operate it because the recoil starting system requires only manual pull-cord engagement, though the 92-pound weight means transport over distance demands planning. The 4-gallon fuel tank runs 26 hours at 25 percent load or 12 hours at 50 percent load, making it suitable for extended outages or multi-day outdoor use without constant refueling. EPA and CARB compliance clears this unit for all 50 states. | The Firman W03386 is a 3,300-watt inverter generator built for RV camping, emergency backup, and light job site work. Its 3,650-watt peak capacity handles startup surges from air conditioning units, refrigerators, and power tools without strain. Because the unit runs on gasoline with a 1.8-gallon tank, users get up to 9 hours of runtime at 25% load before refueling. The inverter topology and sub-3% THD output means laptops, smartphones, and sensitive electronics charge safely without voltage spikes that damage circuitry. At 58 dB, it operates at conversational volume, making it acceptable for residential neighborhoods and campgrounds where noise restrictions apply. This is a mid-sized workhorse for users who need portable power without the weight penalty of larger stationary units. |
- Most PowerfulDuroStar DS4000S3300W running
- QuietestFirman W0338658 dB
- Longest RuntimeDuroStar DS4000S12h at 50% load
Where to buy
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DuroStar DS4000S
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Firman W03386
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