I average 15-16 MPG. I'm on stock 16" wheels with BFG KO2s. You'll want to consider the type of tread for your MPG's. M/Ts will reduce your MPGs the most. I'll see if I can get you a pic soon.
On regearing, I plan on running 255/85/16 soon. It's a 33" skinny. I'm trying to decide what gears to...