On Wed, 19 Jul 2017 11:58:50 -0700 (PDT),
trader_4 wrote:

What you're arguing is like saying that the energy required to move
a bicycle up a hill is different, that you can do it with less
energy input, based on the gear ratio. There is no free lunch.

We both agree that our intuition tells us that the larger diameter results
in better gas mileage.

Yet neither one of us can find a reliable reference that backs up that
claim.

Here's an article on "Tire Size Vs. Gas Mileage"
https://itstillruns.com/tire-size-vs...e-5587784.html

"The most popular notion about how tire size affects fuel economy is that a
tire with a larger diameter will cover more ground per revolution, thus
reducing overall gearing and causing the engine to run at lower revolutions
per minute (RPM). Some assume lower RPM equates with less fuel used to
travel the same distance. Though this idea does have its merits and is true
in some cases, the effect is hardly universal and varies greatly depending
upon the vehicle and the increase or decrease in diameter."

That article concludes the same thing that the Cooper Tire article did,
which is "The only vehicles which stand to benefit from a larger diameter
tire are those produce more torque than they need to in order to maintain
speed."

Both articles mentioned that wider & taller tires reduce fuel economy but
let's keep the wider and taller part out of this discussion because it's
already too complex with just the one change in diameter since most of us
are running on pure intuition.