It will run for approximately 7.2 Hours at 2800W with 3.4 Gallons of fuel.

Technical Spec:

Weight: 144 lbs
Surge Watts: 3,000
Rated Watts: 2,800
Fuel Type: Gasoline
Fuel Capacity: 3.51 Gallons
Dimensions: 25.8 x 18.9 x 22.4