I have used my generator intermittently a lot in the past couple of years, but next week, I will need to use it for about 65 -70 hours, non-stop. I know generators are made to be used, but I just want...
Assuming you have a 4.0KW Onan gas generator, you can expect to use at a minimum 0.5 gallons per hour running one ac in your class C. This is the generally accepted consumption.
I have an 80 gallon tank so I could probably be okay for the entire time, your rig on the other hand may need refueling either by pump or by manual can transfer.
More information would have gotten more and better answers.