I am no math weenie, but I read an article once than basically said that
climbing higher always pays off, no matter the distance. In other words,
level cruise was less efficient than a plan where top of climb was the same
as the beginning of the descent.

I can't prove it though, so I will leave it up for debate like you.



"Elwood Dowd" wrote in message
...
Amen brother. Range was one of the main reasons we chose our Beech
Sierra---only 135-ish knots, but 6+ hours aloft make us faster than a
Bonanza on some trips. Not all, but some. Heck, if you have a Mooney
you get higher speed AND more range (but less headroom).

To answer the original question, if I could spend $1000 to get 5 knots I
would do it, but not 1. If I could spend $5000 and be guaranteed 5
knots I would think about it. If I could spend $10,000 on a turbo that
would take me up higher when I need to climb to be safe, I would
seriously think about it, but I wouldn't count on it to give me lots
more speed.

Regarding range---I have found that for our plane at least, a LOT of
fuel savings can be had by flying at 10,500 rather than 6,500. Speed is
very nearly the same while fuel use drops to about 8.9gph, vs. 10.5 at
the lower altitude. This is not a linear relationship and drops off
above about 13,500. I will leave it to the math weenies to tell me
exactly how long I have to fly for a given leg to get a positive return
from amortizing the climb, but on really long legs I always go up high
and it always pays off.