Does anyone know if these gauges display miles per gallon (or litres per km)
or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

On Fri, 4 Jul 2008 06:29:26 -0400, "Jim" wrote:


"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

It reports MPH everywhere equally well. It doesn't know sea from land
unless you get it wet. It reports speed over the land and if the land
is flooded, at sea or on a river, there may be an effect from
currents.

Casady

"Richard Casady" wrote in message
...
On Fri, 4 Jul 2008 06:29:26 -0400, "Jim" wrote:


"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

It reports MPH everywhere equally well. It doesn't know sea from land
unless you get it wet. It reports speed over the land and if the land
is flooded, at sea or on a river,






THIS IS THE WHOLE POINT. If you are heading against a 5 kt current at 10
kts, what speed will the GPS report?


there may be an effect from
currents.

Casady

On Fri, 4 Jul 2008 11:18:42 -0400, "Jim" wrote:


"Richard Casady" wrote in message
.. .
On Fri, 4 Jul 2008 06:29:26 -0400, "Jim" wrote:


"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

It reports MPH everywhere equally well. It doesn't know sea from land
unless you get it wet. It reports speed over the land and if the land
is flooded, at sea or on a river,






THIS IS THE WHOLE POINT. If you are heading against a 5 kt current at 10
kts, what speed will the GPS report?


there may be an effect from
currents.

Didn't think GPS cared about currents.
If you want to know how fast you're going toward your destination, GPS
can tell you.
If you want to know how fast the water is moving past your speedo
pitot, the boat speedo tells you that - assuming it's working
correctly.
This is what I've heard, anyway.
The graphic (DIP switches) in the link I provided shows the Yamaha
speed sensor can be set to speedo or GPS (NMEA0183.)
Fuel metering DIP can be set for GPH and l/h only.
Looks like no translation to MPG.
All info is good if you make use of it.
So if you assume the boat owner knows his burn per hour (I'd trust
engine rpm more than a fuel flow meter *usually*) and is making a long
run toward a destination, say 100 miles, the GPS speedo is valuable in
calculating whether his fuel will get him there. If it did the
translation and was accurate it would be better.
On some engines a fuel pump/regulator diaphragm can develop a leak and
lose fuel to the intake manifold without real obvious signs. A flow
meter might come in handy for detecting that.
Personally I've found just counting the gallons pumped into the tank
gets me a good enough handle on car mileage. A flow meter seems good
for boats to determine most economical rpm.
From what I've heard the car/boat flowmeters are better at finding the
"best" spot than they are at actually measuring the flow spot exactly.
For instance a guy is reporting he's getting 34 mpg at 65mph on his
car and 31mpg at 75 mph according to his flowmeter.
He's really getting 32 and 29mpg. But the meter does accurately tell
him he's using less fuel at 65mph.
If all or any of the that is wrong let me know.
Your question about a 5kt current and 10kt speed for example.
I think you have to add "apparent" or "true" to the 10kt part to
answer that, but I'm not sure.
Already got a headache.

--Vic

On Fri, 4 Jul 2008 11:18:42 -0400, "Jim" wrote:


"Richard Casady" wrote in message
.. .
On Fri, 4 Jul 2008 06:29:26 -0400, "Jim" wrote:


"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

It reports MPH everywhere equally well. It doesn't know sea from land
unless you get it wet. It reports speed over the land and if the land
is flooded, at sea or on a river,






THIS IS THE WHOLE POINT. If you are heading against a 5 kt current at 10
kts, what speed will the GPS report?

10 knots. But, without the current, you'd be making 15 knots all else being
equal.

"John H." wrote in message
...
On Fri, 4 Jul 2008 11:18:42 -0400, "Jim" wrote:


"Richard Casady" wrote in message
. ..
On Fri, 4 Jul 2008 06:29:26 -0400, "Jim" wrote:


"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres
per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use
those
calculations in determining real miles per gallon over the surface of
the
water.

It reports MPH everywhere equally well. It doesn't know sea from land
unless you get it wet. It reports speed over the land and if the land
is flooded, at sea or on a river,






THIS IS THE WHOLE POINT. If you are heading against a 5 kt current at
10
kts, what speed will the GPS report?

10 knots. But, without the current, you'd be making 15 knots all else
being
equal.
Wrongo old bonged one. The GPS sees you doing 5MPH over ground. What matters
on a boat is your speed thru the water. Speed thru the water is determined
by your throttle position which has a relationship to RPM and GPM. These
things are predictable and repeatable. When you want to know ground speed
toward destination you need to take into consideration current and drift.
Same thing in an airplane. There is ground speed and air speed. They're
different.
Sorry you got bonged. I wonder why Harry got less jail time for a more
flagrant rule violation?

Richard Casady wrote:
On Fri, 4 Jul 2008 06:29:26 -0400, "Jim" wrote:

"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham
The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

It reports MPH everywhere equally well. It doesn't know sea from land
unless you get it wet. It reports speed over the land and if the land
is flooded, at sea or on a river, there may be an effect from
currents.

Casady


I keep my eye on the water, not on the gauges, unless I'm heading into
shallows, and then I watch out for diminishing depth. If I were
"voyaging" over more complicated waters than Chesapeake Bay, I'd pay
more attention to the electronics, I suppose, but I know the land sights
on both sides from Baltimore down to the mouth of the Potomac, so on a
reasonably clear day, I know where I am in space. This is no great
accomplishment...anyone who pays attention while out on the boat around
here can do the same.

On Fri, 04 Jul 2008 08:25:15 -0400, Gene Kearns
wrote:

On Fri, 4 Jul 2008 06:29:26 -0400, Jim penned the following well
considered thoughts to the readers of rec.boats:


"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham

The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.

Au contraire, mon ami!

The Yamaha fuel management gages must receive a fuel flow and GPS (or
speedometer... IMHO,useless) input. You must provide the GPS. I'm not
sure what format(s) of in/output are acceptable, but I suspect it is
configurable to standard formats IOW.... I don't think any special
interface is necessary (since you are likely using the Command Link
interface, already), if the GPS unit outputs a format recognizable to
the FMM..

http://www.yamaha-motor.com/outboard...nk/page05.aspx

No, I think Jim is right.

The link doesn't really give you any information on what data sets are
actually being shared and what format - I would assume NEMA 183.X
which is the defacto standard. The major issue would be connectors on
that harness they supply and how compatiable it is with other units.
However, being NEMA 183 systems, the connector to the hub has to be
something standard - maybe like a N connector or RCA jack.

To the point though, what purpose would having a fuel flow meter do a
calculation based on GPS? The calculation would be simpler and more
efficient to take the fuel flow data in GPH and base the rest of the
calculation on that - position has nothing to do with fuel usage. GPH
has a direct correlation to RPM and MPG - why complicate things?

For instance, if the metering system does the calculations and you
select MPG, then you know if you are using more or less fuel to reach
your destination - X miles equals Y fuel (or the inverse - Y fuel
equals X miles). Same with GPH - X miles equals Y operating time
equals Z available miles.

GPS has nothing to do with fuel usage.

Short Wave Sportfishing wrote:
On Fri, 04 Jul 2008 08:25:15 -0400, Gene Kearns
wrote:

On Fri, 4 Jul 2008 06:29:26 -0400, Jim penned the following well
considered thoughts to the readers of rec.boats:

"Graham" wrote in message
news:ypjbk.54744$Jx.31786@pd7urf1no...
Does anyone know if these gauges display miles per gallon (or litres per
km) or just miles travelled and gallons consumed?

Do they need any special interface to work with standard GPS's like a
Raytheon chart plotter?

Thanks, Graham
The GPS reports miles per hour over land. It would be useless to use those
calculations in determining real miles per gallon over the surface of the
water.
Au contraire, mon ami!

The Yamaha fuel management gages must receive a fuel flow and GPS (or
speedometer... IMHO,useless) input. You must provide the GPS. I'm not
sure what format(s) of in/output are acceptable, but I suspect it is
configurable to standard formats IOW.... I don't think any special
interface is necessary (since you are likely using the Command Link
interface, already), if the GPS unit outputs a format recognizable to
the FMM..

http://www.yamaha-motor.com/outboard...nk/page05.aspx

No, I think Jim is right.

The link doesn't really give you any information on what data sets are
actually being shared and what format - I would assume NEMA 183.X
which is the defacto standard. The major issue would be connectors on
that harness they supply and how compatiable it is with other units.
However, being NEMA 183 systems, the connector to the hub has to be
something standard - maybe like a N connector or RCA jack.

To the point though, what purpose would having a fuel flow meter do a
calculation based on GPS? The calculation would be simpler and more
efficient to take the fuel flow data in GPH and base the rest of the
calculation on that - position has nothing to do with fuel usage. GPH
has a direct correlation to RPM and MPG - why complicate things?

For instance, if the metering system does the calculations and you
select MPG, then you know if you are using more or less fuel to reach
your destination - X miles equals Y fuel (or the inverse - Y fuel
equals X miles). Same with GPH - X miles equals Y operating time
equals Z available miles.

GPS has nothing to do with fuel usage.



Well, this has been a fun read so far.

There are *two* different Yamaha gauges available that display fuel usage.

One is a fuel management meter unit. The other is a speed and fuel meter
unit. Interestingly, the "speed sensor" on the engine is incredibly
accurate, at least it is on my boat. It gives just about the same
reading as the GPS at all times that I have noticed.

The fuel management meter shows flow, fuel available, total consumption,
and miles or nautical miles per gallon. Metric read-outs are also
available.

The speed and fuel meter unit does not display the amount of fuel
available. But it does have functions not available on the fuel
management meter.

I have the Command Link Multifunction Meter Installation Manual somewhere.

As always, have a wonderful day.