wrote:


Besides, power does not give you speed. Power lets you climb and haul more,
but speed goes up as the cube root of power.... i.e. doubling the power gives you
2^(1/3) = 25% more speed for a given airframe. So a Cherokee 180 at 135 mph will go
to at most 170 mph if you could strap on a 360 hp engine.

That formula has always been taken as gospel but the real world truth is
if you could get a 360 hp engine under the cowl you would go a lot
faster than just 170 mph. My buddy and I both have 182's. I have the
standard 230 hp engine, he has the IO-550 300 hp engine in his. Even
though he has more drag because he has much larger tires than I do as
well as bubble windows on both front side windows he typically indicates
30 mph faster thah I do, and he lost 5-7 mph with the 3 8.50 tires over
the 8.00x6 mains and 6.00x6 nose like I have. And while he goes
virtually straight up he cannot legally haul more.