I think on my long trip I was getting high 10's through low 12mpg. I've driven it on a tank or two commuting 90% freeway and saw 11.38..These are all off the odometer though, I'll have to check with my GPS since the larger tires.
I do too, I think I'm going to make or source a swivel mount for the pass seat and put the fridge behind the driver seat.
Nick