Generac GP5500E Published Runtime
- Fuel
- Gasoline
- Tank
- 5.4 gallons
- Published test load
- 50%
- Published runtime
- 10.5 hours
This is Generac's published runtime measurement. Generac does not publish figures for other loads such as 25%, 75% or 100%; runtime at those loads is estimated by GeneratorRuntime and labeled Extrapolated or Estimated from Manufacturer Data — never as a Generac specification.
How Much Gas Does a Generac GP5500E Use?
5.4 gal ÷ 10.5 h ≈ 0.51 gallons per hour at 50% load.
Calculated from Generac's published tank size and runtime. Generac does not publish this figure directly.
Gasoline consumption changes with generator load — lighter loads burn less per hour, heavier loads more. For your expected load, use the calculator above.
What Can a Generac GP5500E Power?
5,500 watts running is the continuous capacity: the total the generator can supply hour after hour. 6,875 watts starting is extra short-duration capacity for the moment equipment with a motor or compressor — a refrigerator, freezer, sump pump or air conditioner — starts up and briefly draws more than it does while running.
Plan your continuous load around the running figure, and check that the biggest motor's startup fits within the starting figure alongside everything else that's on. What fits together depends on your exact appliances, so add yours to see the total load, load percentage and starting demand.
How Long Will a Generac GP5500E Run During an Outage?
Generac's figure is the factual anchor: 10.5 hours at 50% load from a full 5.4-gallon tank. A lighter electrical load may extend that, while a heavier load generally burns fuel faster. Any runtime the calculator shows for other loads is a GeneratorRuntime estimate, clearly labeled as such. Enter the appliances you actually intend to run to plan your outage. Never refuel while the engine is running or hot.
How Much Gas for 24 Hours?
There is no single answer — it depends on load. As a reference point, at Generac's published 50% test condition:
0.514 gal/hour × 24 hours ≈ 12.3 gallons
Estimated fuel requirement if fuel consumption remained equivalent to Generac's published 50% load test. Not a Generac-published figure.
That's about 3 full tanks refilled over the day. For your own load, the calculator's fuel-needed table shows estimates for 8 hours, 24 hours, 3 days and a week. Store gasoline safely in approved containers.
Verified specifications
- Manufacturer
- Generac
- Model
- GP5500E
- Model number
- G0081500
- Generator type
- Conventional portable
- Fuel
- Gasoline
- Running watts
- 5,500 watts
- Starting watts
- 6,875 watts
- Fuel tank
- 5.4 gallons
- Published runtime
- 10.5 hours at 50% load
Source: Generac — View Generac Specifications ↗
Specifications verified: September 25, 2026
Operate it safely
Operate the GP5500E according to Generac's safety instructions: outdoors only, far from doors, windows and vents, with exhaust pointed away from buildings and people. CO-sensing shutoff technology is a safety backup, not a reason to run a generator indoors or in a garage — keep battery CO alarms inside your home.
Generac GP5500E FAQ
›How long does a Generac GP5500E run on a full tank?
Generac publishes 10.5 hours at 50% load on its full 5.4-gallon tank. Lighter loads generally run longer and heavier loads shorter; use the calculator for your own load.
›How much gasoline does the Generac GP5500E hold?
The fuel tank holds 5.4 gallons of gasoline, according to Generac's published specifications.
›How many running watts does the GP5500E produce?
Generac rates it at 5,500 watts running (continuous) output.
›How many starting watts does the GP5500E produce?
Generac rates it at 6,875 watts starting output — extra capacity for a short moment, such as when a motor or compressor starts.
›How much gasoline does a GP5500E use per hour?
At Generac's published 50% load test, about 0.51 gallons per hour (5.4 gal ÷ 10.5 h). This is calculated from Generac's published tank size and runtime, not a figure Generac publishes directly. Fuel use changes with load.
›How much gas would a GP5500E need for 24 hours?
If fuel use stayed equal to Generac's published 50% load test, about 12.3 gallons (0.514 gal/h × 24 h). That's an estimate; lighter loads need less and heavier loads more. Use the calculator for your load.
›Can a Generac GP5500E run a refrigerator?
Many household refrigerators run well within its ratings, but a refrigerator's compressor needs extra power when it starts, and that demand adds to everything else running at the time. Add your appliances to the calculator to check the total load and starting demand.
›How does GeneratorRuntime estimate runtime above or below 50% load?
Generac publishes one runtime, at 50% load. At other loads we adjust that single figure with a general fuel-use curve and label the result "Extrapolated". When your fuel amount differs from the full tank at 50% load, the result is scaled to your fuel and labeled "Estimated from Manufacturer Data". Only Generac's own figure is labeled as manufacturer-published.
Have a different generator? Use the main Generator Runtime Calculator.