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Select up to 4 generators to compare specs, power output, noise levels, runtime and more. Your compare URL is shareable.

  • Firman P03503
  • Yamaha EF5500DE
  • Model P03503
    Model P03503

    Firman 3,550W Gas Generator

    3550W
    Running
    67 dB
    Noise
    View details
  • Model EF5500DE
    Model EF5500DE

    Yamaha 4,500W Gas Generator

    4500W
    Running
    74.1 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 P03503Yamaha EF5500DE
General
Product type
Generator
Generator
Fuel
Gasoline
Gasoline
InverterNoNo
Parallel capableNoNo
RV readyYesNo
Running watts
3550 W
Winner: Winner: 4500 W
Starting watts
4450 W
Winner: Winner: 5500 W
Noise (lower limit)
Winner: Winner: 67 dB
74.1 dB
Weight
Winner: Winner: 108.5 lbs
238.1 lbs
Run time @50% load
Winner: Winner: 14 h
13.5 h
Run time @25% load
Not available
Not available
Fuel tank
5 gal
6.9 gal
Fuel gaugeYesYes
Approx. dimensions (L × W × H)
24.8 x 21.7 x 21.7
29.1 x 29 x 31.5 in
Electrical
Voltage (AC)
120
120/240V 60 Hz
Voltage (DC)
Not available
Not available
GFCI outletsNoYes
Covered outletsYesNo
Automatic Voltage RegulationYesYes
THD
Not available
Not available
Engine
Engine
208 cc OHV 4-stroke, cast iron sleeve.
Yamaha MZ360 OHV 4-stroke
Alternator
Not available
Not available
Starting system
Recoil
Recoil, Electric
Warranty
Warranty
3 years
3 years
Power by fuel
GasolineNot availableNot available
Running watts
Not available
4500 W
Starting watts
4450 W
5500 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
14 h
13.5 h
Run time @25% load
Not available
Not available
Other
Data center
Not available
Not available
Indicators
true
true
Compliance
EPA, ANSI/PGMA G300-2023
CARB, EPA
Security
Not available
Not available
Spark arrestorYesYes
Neutral
Floating
true
UPC
840876135037
765053823098
Core / High-priority specs
Running Watts (Gasoline)
Not available
4500
Starting Watts (Gasoline)
4450
5500
Runtime @ 50% Load (Gasoline)
14
13.5
AC Outlet Types
1x Duplex 120V 20A (5-20R)1x 120V 30A (L5-30R)1x 120V 30A (TT-30R)
2x Duplex 120V 20A (5-20R) 1x 120V 30A (L5-30R)1x 120/240V 30A (L14-30R)
Electrical & power
Frequency
60
60
Engine & construction
Engine Type
OHV 4-stroke, cast iron sleeve
OHV 4-stroke
Engine Displacement
208
358
Cylinder Sleeve
cast iron
Not available
Runtime & fuel system
Runtime @ 50% Load (Gasoline)
14
13.5
Controls & display
Display Type
Not available
Data center
Safety & compliance
Overload Protection System
Low oil and overload protection
Low oil and overload protection
Low Oil ProtectionYesYes
Carbon Monoxide MonitoringYesYes
Included equipment
Documentation
Not available
Data center
Included Accessories
Oil, funnel, tool kit, cover, and wheel kit
Tool kit, battery, and wheel kit
Warranty & identification
Commercial Warranty
3
Not available
Part Number
Not available
EF55DEX
Additional specs
Summary
The Firman P03503 is a 3,550-watt gasoline generator built around a 208cc OHV 4-stroke engine with a cast iron sleeve. This wattage handles mid-range household loads: a refrigerator, microwave, and several outlets running simultaneously, or a modest RV power setup. The 5-gallon fuel tank delivers 14 hours of runtime at 50% load, meaning a full tank covers a typical overnight camping trip or a daytime power outage without refueling. The 4,450 starting watts give it enough surge capacity to turn on air conditioning compressors or well pumps, making it practical for both emergency backup and recreational use.
The Yamaha EF5500DE is a versatile dual 120/240 volt generator, ideal for emergency backup power for home, cottage, or business, as well as primary power on job sites. It features a 358cc OHV engine, electric start, and offers 5500 watts maximum AC output with outstanding fuel efficiency.
  • Most Powerful
    Yamaha EF5500DE
    4500W running
  • Quietest
    Firman P03503
    67 dB
  • Longest Runtime
    Firman P03503
    14h at 50% load
Where to buy
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Firman P03503
Store links
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Yamaha EF5500DE
Store links
No links yet.
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