Fuel Consumption Curves - Navman Datahelm 8120 Installation And Operation Manual

13-3 Fuel consumption curves

A fuel consumption curve is a powerful
tool for assessing your boat performance in
different conditions and for helping you to
run at the most economical speed for the
conditions. Fuel consumption curves require
engine RPM, which requires SmartCraft or
diesel sensors to be installed.
13-3-1 Making a fuel consumption curve
Making a fuel consumption curve requires
running the boat in a straight line through
the engine's full RPM range for about 15
minutes.
For your first curve, choose a calm day with
light wind and little current; have a typical
load and a freshly cleaned hull. Then you can
make fuel consumption curves for different
boat, weather or sea conditions. Compare
these with your first curve to see how your
boat's performance changes with conditions.
Making a curve
1 Start running the boat in a straight line.
then select Fuel.
2 Press
SETUP
3 Select Fuel consumption curve,
then select New.
4 Enter the comfortable maximum RPM you
have measured for the engine. Do not use
the maker's maximum RPM.
5 The Instrument then asks you to set
the minimum RPM. Set the throttle for
minimum RPM; for a twin engine boat set
both engines to about the same minimum
RPM.
Now, do not change the engine speed.
Wait for about 60 seconds for the boat to
stabilise, then press
Instrument records the data.
48
. Wait while the
ENTER
6 The Instrument then asks you to set the
throttle to achieve a target RPM. For a twin
engine boat set both engines to about
the target RPM. When the engine RPMs
are correct, the Target RPM box will turn
green.Now, do not change the engine
speed. Wait for about 60 seconds for the
boat to stabilise, ensuring the Target RPM
box stays green. Then press
while the Instrument records the data.
7 The Instrument repeats the above step to
record data up to the maximum RPM.
Then the Instrument asks if you want to
save the curve. Select Yes. The Instrument
asks for a name for the curve. Change the
default name if required, then press
The new curve is stored.
Note
To interrupt making the curve at any time,
press .
ESC
8120 Installation and Operation Manual
. Wait
ENTER
.
ENTER