Don, let me welcome you to iRV2.com. We are glad you have stopped by and joined us here. I am not sure as to the milage you would get from the unit and the two chassis choices. Some variations will apply such as if you are towing or not and the terrain you will be in. I would guess you will get between 7 & 8 mpg. Good luck and enjoy the hunt. I am sure there are some of our members that can be more specific in answering your question. I'll put a shortcut into the New Member section.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7