Stripit,
I have 2 2.5 gallon gas "cans" (they're plastic now a days) that I use for gas. I leave them empty until I am in a dry camping situation. I averaged over 5 to 6 hours before I got too antsy and went out and filled the tank up. It holds .9 gallon from what the book says. I use the special auto throttle setting so it only revs up to meet the demand instead of running full throttle all the time. I don't like to let it run dry as I usually have my computer on and hate it when it gets shut down unintentionaly. I dry camp in the winter when I won't need the AC to cool off.
A buddy of mine uses one 2.5 gallon can and a 5 gallon can. He fills the gen only from the smaller can. He also fills when the gen is running but that scares the bejeebees outa me and I won't do that. Something about immolation just turns me off.
When I'm through dry camping I use the gas in my motorcycle to burn it up. I try not to carry any in the cans if I can help it. It goes "sour" too darn fast. Conversely if I need the gen in a hurry I'll pump some gas out of the bike for the gen while I later go to the station and fill a can. (or the bike again)