"DT" == Dan Thomas writes:
DT Even an old Aircoupe with a C90 accelerated better
DT than the 150, again with about the same power/ weight ratio.

Hey! That's my Aircoupe yer talkin' about. Correct, the Alon
Aircoupes (not so true of the ERCO 415 Ercoupes, the original and far
more common variant) are much more efficient than the C-150. It's not
the engine as much as the aircraft. On a
good day I can get 100kts TAS from my Aircoupe, but that's with a
cruise prop (52" pitch).

A friend has a 415 model Ercoupe with an O-200. I can still outrun
him but it's not quite a fair comparison, because I think he has a
climb prop. He will outclimb me, but not my a lot. The 415s are
fairly draggy.
--
Mythology is what we call someone else's religion.
~ Joseph Campbell