"basskisser" wrote in message
m...
"Joe" wrote in message
.. .
You forgot to answer my question-

Here's real world scenario for you- On my boat (21.5' CC 200hp), at
3000rpm
the boat will ride with a bow high attitude with stern dive. As I
actuate
the trim tabs the stern rises, the bow lowers and the boat planes. Once
planed the rpm's will immediately climb (without touching the throttle)
and
my speed increases. I then can reduce throttle back to 3000rpm and
continue
along on a plane.

Now, tell me, do you think my boat is more, or less efficient at
3000rpm's
with my tabs down or tabs up?

Uh, you are changing the subject here. You previously said more FUEL
efficient, now you are simply saying efficient.

They're directly related. So I am saying both

As far as fuel efficiency goes, 3000rpm is 3000rpm, whether the boat is
running flat
in the water, or straight up, so no, your fuel effeciency hasn't
increased. Your ride may be better, at the SAME fuel rate, but your
fuel effeciency hasn't changed.

You're wrong again. Here's a hint- manifold vacuum.
Observe the fuel efficiency of one boat towing another boat running at 3000
rpm's and then compare it to the same boat while not towing another boat
running at 3000 rpm's.
Do you think it's the same? According to your theory it is.

On my boat I have to REDUCE the throttle to maintain 3000 rpm's after
actuating the trim tabs. Tell me how I could possibly.
be running at the same efficiency.

Do you not understand that? Do you
also not understand that when you use a tab, you are sticking a metal
plate out to drag in the water?

With a tab you are actuating a plate angularly to deflect water, when used
correctly the deflection will decrease the wetted area of the hull by
raising the stern, and lowering the bow. Other benefits are reducing the
surface area of the lower unit exposed to water, and more efficient prop
angle.

Now, again, answer me....do you think
it is more fuel efficient to create drag by using trim tabs, or to
distribute weight to achieve the same ride characteristics?

Yes, it is more efficient to properly engage the tabs than to distribute
weight.