On Wed, 19 Jul 2017 18:06:55 -0400,
wrote:

It CAN be true though at certain speeds, with certain engines, because
you drop the RPM of the engine, and if that drop gets the engine "off
the cam" the torque output of the engine suffers , in some cases a
WHOLE LOT.

It seems that the torque curve is almost everything when it comes to adding
inches to the diameter of the tire and wheel assembly.

Without knowing the torque curve, there's no way to predict the result, but
most accounts I referenced said that your chances are greater that you'll
lose mileage than you'll gain it.

But, everything depends on the variables, which I tried to remove in the
original question - but - they return with a vengeance because the
variables determine whether or not you gain mileage - not the diameter of
the end result.