X2 on the above post although on a $100K rig insurance is closer to $1200. I'm a lot heavier weight weight wise (44K) and right foot wise than most and average 7 MPG so I'd say closer to 9 at 30-33K. A strong head wind will decrease it about 1 mpg, but a good tail wind will be +1. Only problem with taking advantage of a tail wind is you often end up in the wrong place.:B
I've modified my dash AC so the compressor runs all of the time and rarely do I have to run the generator and roof ACs. At aprox 1/4 tank the generator will run out of fuel so you still have fuel to get to a truck stop. Diesel generator will use aprox 1/2 gallon/hour for one AC and 3/4 for two AC... $2/hour to stay comfy.
