Now takes 87 Gallons at 15 gph@135kts - 2500 ft. Can go 145 but burns 19 gph at low altitudes.
That's even worse than I thought, for a C182. Is this leaned to peak or LOP?
A TB20 does 138kt IAS (low levels, say below 10,000ft) at 10.5 GPH. But it doesn't have the short field performance of a C182.
I think broomstick is right on the mark. Cessna can't possibly do anything else. It will be a Lyco engine, and the rest follows.