I just had BFG AT 285/70/17's installed and love the look. It completely transformed the appearance of the truck, but wow at the reduced fuel mileage! I was getting a solid 19.5MPG out of my 2010 4x4 and now it's getting only 15.1!
I'm seriously considering going back to my stock wheels and tires since I drive about 40,000 miles per year. That translates to an extra $1,794 per year in fuel cost, on top of the $3,000 I spent on a lift kit, tires and wheels.
I'm taking a road trip to Augusta, GA today and I'll see if backing down from my usual 75-80MPH to 65-70MPH gets enough of my mileage back to keep the new tires on.
I've put bigger tires on all kinds of vehicles from Jeep CJ's to Ford Diesel F-350's and I don't think I've ever seen a 4.4MPG hit by going up about an inch on tire size!