Champion 3100 - running an AC - how many hrs out of a tank?

I just ran our new 3100 in 103 degrees temps outside full sun running 1 AC in a 30' fifth wheel for two days. We were able to get 4 1/2 hrs of run time on a tank of gas on eco-mode. It seemed to be running at 3/4 speed because if i flipped to full run it would speed up some. I was very happy with its performance and ease. I was very pleased with how quiet it is in a campground. I walked to the next camp on both sides and could barley hear it. Our neighbor next to us complemented how quiet and asked what brand because he needed a bigger one to run the AC because his Honda 2000i could not. He didn't want to drop another grand on A Honda to run AC a few times a year. I told him I was the same and went with the 3100 and sold my Honda for $650 to a friend and bought the 3100 for $699. So far for the few times a year i will even use a generator I am very happy with the 3100.