A 10% reduction in rolling resistance = ? MPG increase.

You are making a fool of yourself by repeating the same nonsense in a larger font. Take some time to go back to first principles instead of mis-quoting things you don't understand. There is a cubic relationship between aero drag and power, but not aero drag and fuel consumption.

 

this is here we go around the merry-go-round again

the question undisputedly is one of MPG. Im saying MPG is a direct function of power required. More power = more fuel, pretty well understood by anyone. lbs/hp/hr

And we can see from the chart that principally the causal relationship to power required is aero drag, so although the drag as a value goes up by the square, the fuel consumed creating the power required to drive it is by the cube, otherwise there would be no point in mentioning it, and as its looking, why you edited it out. So here it is again...

"it indicates precisely what we should expect. Since the question relates to MPG, which is a function of power required, we need to consider that aero drag is a cube root law, that is it takes around 8x the power to achieve twice the speed."

now I would concede it might have been better if I had put it as:

"it indicates precisely what we should expect. Since the question relates to MPG, which is a function of power required, we need to consider aero drag as a cube root law, that is it takes around 8x the power to achieve twice the speed."

however, the principle stands

 

You are still confusing drag with power. Power is function of drag x velocity. Maybe someone else will come along and explain it to you. I give up.

 

seems like a lot...
I just had a look at ecomodder site and recovered this
aero mods-data-% change or Cd change ( installment # 7-Wheels/Tires/Wheelcovers/etc. - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

'1982,Pontiac Trans Am Firebird wind-tunnel studies show Larry Shinoda's trick aero wheel-covers trim 0.027 off drag coefficient,compared to a open wheel.'

and while not directly relating to this discussion, this part is interesting

'1986, wind tunnel development work for Subaru XT show a drag increase of 5.1 % when tire size is increased from 155 to 185 series radials.Drag is reduced 2.0 % due to "air flaps" steering air over rear tires.Completely flat/sealed wheel-covers show a 2.75 % drag reduction.'

something to think about I guess

 

Does seem pretty high - but the Model S standard wheels are pretty big - a lot bigger than the wheels in your reference which probably generate a lot more drag. Not to mention that the Model S is otherwise very aerodynamic otherwise so the wheels very likely represent a larger percentage of overall drag compared to your typical car.

I'm sure someone will run some actual tests with the 2 different sets of wheels so we'll have actual data some time next year.

 

from a look at some of their forums, at least in the few bits I looked at, the people talking there dont seem to have much of a clue as yet

time will tell I guess. But if form and fashion are anything to go by, small diamter wheels should make a comeback