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  • Firman T08072
  • Genmax GM15000ET
  • Model T08072
    Model T08072

    Firman 8,000W Tri-Fuel Generator

    8000W
    Running
    74 dB
    Noise
    View details
  • Model GM15000ET
    Model GM15000ET

    Genmax 13,000W Tri-Fuel Generator

    13000W
    Running
    76 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 T08072Genmax GM15000ET
General
Product type
Generator
Generator
Fuel
Tri-Fuel
Tri-Fuel
InverterNoNo
Parallel capableNoNo
RV readyYesYes
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: 213 lbs
242 lbs
Run time @50% load
Winner: Winner: 12 h
11 h
Run time @25% load
12 h
Not available
Fuel tank
8 gal
10.5 gal
Fuel gaugeYesYes
Approx. dimensions (L × W × H)
29.8 x 27.5 x 26.1
28 x 31.6 x 28.7
Electrical
Voltage (AC)
120/240
120/240
Voltage (DC)
Not available
12
GFCI outletsYesNo
Covered outletsYesYes
Automatic Voltage RegulationYesYes
THD
Not available
23 %
Engine
Engine
439 cc OHV 4-stroke.
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
GasolineNot availableNot 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
Natural gasNot availableNot available
Running watts
5500 W
12000 W
Starting watts
6900 W
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
PropaneNot availableNot 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
Not available
Not available
Run time @25% load
Not available
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 arrestorYesYes
Neutral
Bonded to frame.
Floating
UPC
840876180723
760790901382
Core / High-priority specs
Running Watts (Gasoline)
8000
11000
Running Watts (Propane)
7250
13000
Running Watts (Natural Gas)
5500
12000
Starting Watts (Gasoline)
10000
15000
Starting Watts (Propane)
9050
13000
Starting Watts (Natural Gas)
6900
12000
Runtime @ 50% Load (Gasoline)
12
11
AC Outlet Types
1x Duplex 120V 20A (5-20R) GFCI; 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
439 cc OHV 4-stroke
OHV 4-stroke
Engine Displacement
439
520
Cylinder Sleeve
Cast iron sleeve
Not available
Engine Oil Type
Not available
SAE 10W/30
Runtime & fuel system
Runtime @ 50% Load (Gasoline)
12
11
Safety & compliance
Overload Protection System
Low oil and overload protection.
Low oil and overload protection
Low Oil ProtectionYesYes
Carbon Monoxide MonitoringYesYes
Included equipment
Mobility Components
Yes
Not available
Starting Components
Not available
Recoil starter; Electric starter; Remote starter
Included Accessories
Oil, funnel, tool kit, natural gas hose with NPT adapter, 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 T08072 is an 8,000-watt tri-fuel generator built for users who need flexibility across fuel sources and sustained power output. Running on gasoline, propane, or natural gas, this unit delivers 10,000 peak watts on startup, enough to handle simultaneous demands like air compressors, power tools, and household appliances. The tri-fuel capability means users can switch fuels based on availability and cost, a significant advantage for job sites, RV travel, or emergency backup where fuel supply chains vary. On gasoline, the T08072 runs at full 8,000 watts. On propane, output drops to 7,250 watts. On natural gas, it falls to 5,500 watts. This tiered output reflects the energy density of each fuel type and shapes what users can realistically power during extended outages or remote work. The 8-gallon tank delivers 12 hours of runtime at both 25% and 50% load on gasoline, meaning users can operate a moderate load overnight without refueling. For job sites and backup power scenarios, this runtime eliminates mid-shift fuel stops.
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 Powerful
    Genmax GM15000ET
    13000W running
  • Quietest
    Firman T08072
    74 dB
  • Longest Runtime
    Firman T08072
    12h at 50% load
Where to buy
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Firman T08072
Store links
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Genmax GM15000ET
Store links
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