Generac GP8000E published runtime
Generac's spec sheet for the GP8000E model 8929 lists 15.5 hours at 25% load and 12 hours at 50% load on a full 7.9-gallon tank.
Other GP8000E versions (such as the 49-state model 7715) publish different runtimes, so check the model number on your generator's label.
Verified specifications
- Manufacturer
- Generac
- Model
- GP8000E with COsense (EFI)
- Model number
- 8929
- Model codes
- 8929-0 / G0089290
- Generator type
- Conventional
- Gasoline: running
- 8,000 watts
- Gasoline: starting / max
- 10,000 watts
- Gasoline: tank
- 7.9 gallons
- Gasoline: published runtime
- 15.5 hours at 25% load on 7.9 gallons
- Gasoline: published runtime
- 12 hours at 50% load on 7.9 gallons
- Voltage
- 120/240V
- Frequency
- 60 Hz
- Engine
- Generac 420cc OHV with EFI
- Displacement
- 420cc
- Weight
- 207 lb
- Starting system
- Electric start, recoil backup
- CO safety
- COsense
Source: Generac GP8000E spec sheet, model 8929 — View Generac Specifications ↗
Specifications verified: September 28, 2026
How much gas does the GP8000E use?
- At 25% load: 7.9 gal ÷ 15.5 h ≈ 0.51 gallons per hour
- At 50% load: 7.9 gal ÷ 12 h ≈ 0.66 gallons per hour
These are our calculations from Generac's published tank size and runtimes, not Generac figures.
Manufacturer figures vs. our estimates
Only the runtimes listed above are Generac's own published figures. When your load and fuel amount exactly match one of them, the calculator labels the result Manufacturer Published Runtime. Loads between published figures are labeled Estimated from Manufacturer Data, and loads outside the published range are labeled Extrapolated with a wider range. Those are GeneratorRuntime estimates, not Generac specifications.
Operate it safely
Like every portable generator, the Generac GP8000E must be operated according to the manufacturer's safety instructions: outdoors only, well away from doors, windows, and vents, with battery CO alarms inside your home. A CO shutoff feature is not a substitute for safe placement. Never refuel while the engine is running or hot.
Generac GP8000E FAQ
›How long will a Generac GP8000E run on a full tank?
Generac's spec sheet for model 8929 lists 15.5 hours at 25% load and 12 hours at 50% load on the 7.9-gallon tank.
›What is the GP8000E runtime at full load?
Generac does not publish a full-load runtime. The calculator extrapolates beyond 50% load and labels those results "Extrapolated" with a wider range.
›How many watts does the Generac GP8000E produce?
8,000 watts running and 10,000 watts starting at 120/240V, according to Generac.
›Which GP8000E does this page cover?
Model 8929, the 50-state GP8000E with an EFI engine and COsense. The 49-state model 7715 lists 10 hours at 50% load, and older versions (7676, 7686) have different figures, so they are not covered here.
Similar generators
- FIRMAN T08073 Tri-Fuel (T08073) — 8,000 watts running
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- Generac GP7500E Dual Fuel with COsense (8011-2) — 7,500 watts running
- Westinghouse WGen9500 — 9,500 watts running
- Generac GP6500 with COsense (7680) — 6,500 watts running
- Generac GP5500E (G0081500) — 5,500 watts running
Browse the full Generator Runtime Database or use the main Generator Runtime Calculator.