Question on fuel consumed by our generator AND ??

Certainly, it s. Hard to provide any intelligent info when your asking such a wide question, and with out providing info concerning your setup.
So, when you feel free enough to either provide the Onan model number or if it is lp, gasoline or diesel fueled, you can expect a more intelligent response.
You have to understand, we can not see what your looking at nor talking about.
Dave M