People will always modify trucks... but my readings so far yes MPG is going to take a hit. But the truck doesn't really sit like a 4x4 which bothers me. maybe a leveling kit will make me happy.
I know what you mean. Mine sits more like a 2 x 4. I put 315 75 x 17 on mine without a lift, and my millage did not suffer, it still sucks at 22 - 23 highway.
What kills milage on a lifted truck is the additional wind that gets under the truck and plays havoc with all these exposed components and protruding frame parts,and yes, bigger tires. If there was a way of streamlining the underside to prevent all those odd shaped items from catching wind it would help. Maybe a plastic shroud or super large skid plate that would cover most of the exposed items. But then, this would cause overheating of 4X4 components when you offroad since the heat from those components could not escape as easily. (Tranny heat, transfer case heat, catalytic converter heat). Its sounds like a good project for some of you younger and more energetic guys.