Jose wrote:
But, and it is a big but, think of the settings we run on takeoff, and
landing (in case you have to do a go-around) and of the time you are
at idle, or low power on the ground.


Most of the time will be spent at cruise (unless you are in the
pattern), so I would not expect that to be all that much.



A FADEC on a plane like a 182 will save on average 2 GPH, that's huge.
So saying a FADEC in and of itself is not what makes it more efficient
is theoretically true but it is practically true. A human will never be
able to operate the engine at its most efficient, for a computer it is
simple.