Tire size differences.. my R888s are wider

[MrQuick]

I'd be interested in seeing how much of a difference you get when they are mounted and inflated. I'm sure there will still be a difference, but I wonder if it would be as much as you're seeing with just the tire alone.

I agree, that tire has been sitting on a stock shelf for all its life. But its not unhead of. My Pilot Sports fit tighter than my BFG's. Im guessing side wall construction.