I second your opinion! Mpg is much more important than gph.
Taking the chart one step further--adding the conversion for mpg we have:

RPM MPH Knots GPH MPG
650 3.7 3.2 0.9 4.1
1000 5.8 5.0 1.2 4.8
1500 8.1 7.0 3.4 2.3
2000 15.6 13.6 5.1 3.1
2500 24.4 21.2 6.0 4.1
3000 31.7 27.6 8.2 3.9
3500 39.6 34.4 11.8 3.4
4000 45.3 39.4 13.5 3.4
4500 49.9 43.3 17.2 2.9
4750 54.1 47.0 22.6 2.4


I wish I got such great "economy"! I average only about 2mpg with my 200hp
merc.
I usually run 3/4 throttle (35-40mph) for 9miles to the pass then troll or
run as fast as I
can safely and comfortably go to a bottom fishing spot. My boat has twin
18gal and a
third 17gal tank and consistantly, with a mix of trolling and crusing gets
between 1.9 to 2.1 mpg.
I keep a log with fishing, weather info and how much gas I put in. Maybe to
determine
the overall running time on the engine an hour meter is good but I could
care less about
how many gallons it takes me to move for one hour. Once I've commited to go
fishing,
I just want to be sure I have plenty of gas to get back! In the example
it's obvious that at 1500 rpm the boat's trying to get on plane and at
2500rpm it's on plane and
that WFO is inefficient (and not too good on the engine life either).
Notice that, once it's on plane
at 24.4mph it's as efficient as creeping along at 3.7mph. But within the
parameters of 3.7mph
to 45.3 mph (avoiding the 1500 rpm), there's not much difference. And, in
the example,
is one really going to run 5.8 mph for 30 miles just for economy? If I run
any distance at 3.7 or 5.8
mph it's because I trolling--not trying to save gas. If I really wanted to
save gas
I guess I'd get a sailboat! Let's go fish!
LD

"tony thomas" wrote in message
news:QOY5e.1364$xL4.780@attbi_s72...
On average you will get between 2.5 and 3.0 miles per gallon. This
assumes
you are running on plane and are running between 3000 and 4000 rpms. The
lower the rpms the better the mileage.

Everyone wants to quote gallons per hour at a certain rpm. How many hours
do you run at the same rpm? Miles per gallon means so much more as you
should know how far you have gone using either a chart or a gps. This
will
tell you exactly how far you can still go on a given amount of fuel.

Of course that is my opinion.
--
Tony
my boats and cars at http://t.thomas.home.mchsi.com


"John H" wrote in message
...
Does anyone have something that will tell me what the fuel consumption
expectations are for a Pro-line 211 walkaround with a 5.7L carbureted
engine?

It's listed in the Powerboat Guide, which I'm too cheap to buy just to
get
this
question answered.

I'm also too cheap to put a fuel meter on it.

Actually, I'm so cheap I may not burn the electricity to turn this
computer on
to get an answer....but I'll love you if you try.

Thanks!
--
John H

"All decisions are the result of binary thinking."