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  • Firman WT05571
  • Generac #8150 GP5500E
  • Model WT05571
    Model WT05571

    Firman 5,500W Tri-Fuel Generator

    5500W
    Running
    67 dB
    Noise
    View details
  • Model #8150 GP5500E
    Model #8150 GP5500E

    Generac 5,500W Gas Generator

    5500W
    Running
    0 dB
    Noise
    View details
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).
Generator Specifications Comparison
SpecificationFirman WT05571Generac #8150 GP5500E
General
Product type
Generator
Generator
Fuel
Tri-Fuel
Gasoline
InverterYesNo
Parallel capableYesNo
RV readyYesNo
Running watts
Winner: Winner: 5500 W
Winner: Winner: 5500 W
Starting watts
6850 W
Winner: Winner: 6875 W
Noise (lower limit)
Winner: Winner: 67 dB
0 dB
Weight
Winner: Winner: 131.4 lbs
163 lbs
Run time @50% load
Not available
Winner: Winner: 10.5 h
Run time @25% load
14.5 h
13.4 h
Fuel tank
5.3 gal
5.4 gal
Fuel gaugeYesYes
Approx. dimensions (L × W × H)
27.6 x 21.3 x 22.6
30 x 27 x 25
Electrical
Voltage (AC)
120/240
120/240
Voltage (DC)
12
Not available
GFCI outletsYesYes
Covered outletsYesYes
Automatic Voltage RegulationYesYes
THD
3 %
Not available
Engine
Engine
322 cc OHV 4-stroke, cast iron sleeve.
Generac OHV 4-stroke
Alternator
Not available
Not available
Starting system
Recoil, Electric
Recoil, Electric
Warranty
Warranty
3 years
2 years
Power by fuel
GasolineNot availableNot available
Running watts
5500 W
5500 W
Starting watts
6850 W
6875 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
10.5 h
Run time @25% load
14.5 h
Not available
Natural gasNot availableNot available
Running watts
4500 W
Not available
Starting watts
5500 W
Not available
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
PropaneNot availableNot available
Running watts
5000 W
Not available
Starting watts
6250 W
Not available
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
9.5 h
Not available
Other
Data center
Not available
Not available
Indicators
Not available
false
Compliance
EPA, ANSI/PGMA G300-2023
CARB, EPA
Security
Not available
Not available
Spark arrestorYesYes
Neutral
Bonded to frame
true
UPC
840876155714
696471104639
Core / High-priority specs
Running Watts (Gasoline)
5500
5500
Running Watts (Propane)
5000
Not available
Running Watts (Natural Gas)
4500
Not available
Starting Watts (Gasoline)
6850
6875
Starting Watts (Propane)
6250
Not available
Starting Watts (Natural Gas)
5500
Not available
Runtime @ 50% Load (Gasoline)
Not available
10.5
Runtime @ 25% Load (Gasoline)
14.5
Not available
Runtime @ 25% Load (Propane)
9.5
Not available
AC Outlet Types
1x Duplex 120V 20A (5-20R) GFCI; 1x 120V 30A (TT-30R); 1x 120/240V 30A (L14-30R); 1x 120/240V 50A (14-50R)
2x Duplex 120V 20A (5-20R) GFCI1x 120/240V 30A (L14-30R)
Electrical & power
Frequency
60
60
Engine & construction
Engine Type
OHV 4-stroke
OHV 4-stroke
Engine Displacement
322
298
Cylinder Sleeve
cast iron sleeve
Not available
Engine Oil Type
Not available
5W-30
Runtime & fuel system
Runtime @ 25% Load (Gasoline)
14.5
Not available
Runtime @ 50% Load (Gasoline)
Not available
10.5
Safety & compliance
Overload Protection System
Low oil and overload protection, CO monitoring
Low oil and overload protection
Low Oil ProtectionYesYes
Carbon Monoxide MonitoringYesYes
Included equipment
Mobility Components
Not available
Yes
Starting Components
Oil, funnel, tool kit, propane hose, and battery
Recoil, Electric
Included Accessories
Oil, funnel, tool kit, propane hose, and battery
Oil, Funnel, Tool Kit, Battery, and Wheel Kit
Warranty & identification
Commercial Warranty
3
2
Part Number
Not available
8150
Additional specs
Summary
The Firman WT05571 is a 5,500-watt tri-fuel generator that runs on gasoline, propane, or natural gas. On gasoline, it delivers 6,850 starting watts and 5,500 running watts, enough to power a full home electrical panel during an outage or run multiple job site tools simultaneously. On propane, output drops to 6,250 starting and 5,000 running watts. On natural gas, it falls to 5,500 starting and 4,500 running watts. This fuel flexibility means users can switch between sources based on availability, cost, or storage preference without buying multiple generators. The tri-fuel capability makes this unit valuable for homeowners in regions with natural gas infrastructure, RV owners who can refill propane at any campground, and contractors who need to adapt to job site fuel availability. The 3 percent THD rating protects laptops, televisions, and other sensitive electronics from voltage spikes that damage circuits. At 67 decibels, the noise level sits between a typical conversation and heavy traffic, making it suitable for residential neighborhoods but audible enough that neighbors will know it is running.
The Generac GP5500E is a 5,500 watt gasoline generator built to power whole house essentials during outages or on job sites. Its 6,875 starting watts handle motor driven appliances like well pumps and air conditioners that demand heavy inrush current. For homeowners and contractors who want reliable backup without crossing into stationary generator territory, the GP5500E delivers meaningful output with the refueling simplicity of gasoline.
  • Most Powerful
    Firman WT05571
    5500W running
  • Quietest
    Firman WT05571
    67 dB
  • Longest Runtime
    Generac #8150 GP5500E
    10.5h at 50% load
Where to buy
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Firman WT05571
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Generac #8150 GP5500E
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