The PA-23-180 I used to fly would cruise well into the 160's IAS. Never
set out to see what it's actual service ceiling or single engine service
ceiling or TAS was. I have a POH if you have any questions that might
have answers there, though the altitude performance chart is unreadable.

Robert Bates wrote:
I'm thinking about buying an Apache but can't find performance data for a
160hp Geronimo or a turbo. Also, does anyone have real world data for a
180hp Geronimo rather than what's on the website?