Measuring MPG

Elessar

Elessar

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So I asked a few weeks ago who has what. Jez suggested the Navman 3200 but I can't seem to get one. Northstar have taken on Navman but only do a petrol version.
The Floscan website is so poor I've given up in frustration.

Accurate measurement of MPG must be a good thing, I wonder why there aren't more products on the market. What do you all do, or don't you bother?
 
scroll down the ad jez it says
DUE TO OVERWHELMING RESPONSE, WE HAD SOLD OUT THE LAST UNIT. IF YOU ARE INTERESTED, PLEASE PLACE YOUR ORDER AND DELIVERY LEAD TIME IS ABOUT 2 TO 4 WEEKS.
Sending the money to Singapore for a lead time described as "about" put me off.
 
It's not mpg you want to know, it's gallons per hour and to find this figure will take a lot of motoring before you will know the answer i.e revs, tidal flow, windage, slippage, slime, barnacles, the list is endless AND AT THE END OF THE DAY, YOU WILL STILL BE UNABLE TO AFFORD IT. So why worry no use getting paranoid. Enjoy!!
 
no, its mpg.

gph is irrelevant unless you also know speed, and with that you actually work out mpg. GPH is useful for a remian fuel calc, but doesnt give you any clue as to how efficiently you are running.

at x-knts I use 8gph, at y-knts I use 13gph. I am 100 miles from port with 60 gallons of fuel left. what speed should I go at to ensure I get there?

Without knowing the speed, and therefor the mpg it is impossible to know...
 
8 gallons per hour at 15 knots = 2 MPG ROUGHLY. 1 mile will be covered in 4 minutes, 100 miles will be covered 400 minutes, providing that the earth stands still and the tide is with you.
 
Have to agree with your sentiment, useful though these gizmos are you can work out your gph from the manufacturers data and equivalent boat tests etc... that and a bit of experience gives you mpg as well. But you will never get the cost of the meter back, their just another toy, better to just get to know your boat better.
 
What's wrong with Floscan website?
Maybe it's not as flashy as some others sites, but I can't think of any information you'd need to get that isn't available in their site.
Besides, their products are absolutely the best - Navman were children toys in comparison.
Being the best, obviously they're not cheap either, but I don't agree with those who consider these instruments useless.
Depending on the type of cruising you're aiming at, they might be just useful, up to almost necessary.
 
I use Kiss technology, keep it simple stupid. MY boat does about 1.3 to the gallon and holds 150 gallon in normal tanks, but can add in another 45 gallon if I have to. Max range I have ever used is about 130 miles. But preffer less than 100. Your fuel meter is only ever going to tell you past history, not what your going into. Give it a wide berth.
 
Are your volvo engines EVC or EDC? If yes you can buy a volvo gizmo (dfferent part # depending on EVC or EDC) that will tell you this. You can interface it to your GPS via NMEA and it will give you MPG. It's a simple plug an play device; you dont need to fit any fuel flow sensors cos they're already installed and this gizmo is just displaying data that is already sloshing around on the canbus

I agree MPG is much more use than GPH. Though as Omega says, you need to factor in tide etc when using MPG data read from one of these gizmos, becuase they compute based on SOG not STW

I use one and it's great. Really useful to learn what speeds/throttle positions give you best MPG. And a big safety benefit when you are doing long crossings when you must know your range accurately

Also with these volvo gizmos you only need one, even if you have two engines. In fact, imho one is etter than two
 
I'm sorry but how do you think you know what I can afford and what I want to measure?

Whatever, you're wrong on both counts, I want to measure MPG so I can see (and not have to work out) the speed that will give me maximum range in a given sea state and other variables you mentioned.

And when I fancy going flat out I'll still be able to afford it.

Enjoy? - I do thank you!
 
Thanks - 2 very mechanical mercs I'm afraid so no plug in gizmos.

You completely got the point as to why I want one. Interesting to get 1 only, I was hoping that the accurate tachometer would help me sync the engines and an mpg differential would help spot impending engine problems. Is that not worth the extra i ponder.......
 
[ QUOTE ]
Is that not worth the extra

[/ QUOTE ]Imho, yes.
Maybe jfm suggested a single dial because with the Volvo gizmo you can switch it to each engine, without the need to purchase two of them - though I'm actually not sure if that's the way VP system works.
But If you're going to install it, I'd definitely put it on both engines, for the good reasons you already mentioned.
I don't know why you didn't find what you need on Floscan website, they have a very handy model selector in this page.
The only thing they don't include in their packages is an instrument capable of sending the speed via NMEA connection, which is obviously necessary to calculate the MPG.
But that's something any GPS can do. And btw, you could also use a speedometer (again, with NMEA output of course), if you prefer to have MPG calculated based on STW rather than SOG.
Maybe you could even put a selector and connect the Floscan to both a GPS and a speedo during operation, thus being able to check both.

PS: on a side note, I also guessed that you had VP diesels on your S37, but assumed they were pre-EVC/EDC. In your initial post, you seemed concerned abot Navman only doing a petrol version...?
 
MPG is obviously better info than GPH even though all you really have to do is simple maths to get MPG from GPH. This is why I can’t understand what Raymarine are playing at with their C series (and E & G for all I know). I sourced the Volvo part to convert J1939 to NMEA2000 and it was “plug ‘n’ play” as has been mentioned, instantly giving the info. But, the C series already has SOG info (and in my case also STW as I have it interfaced with the log) so a simple bit of software to do the calcs. on the fly and display it would be easy but it’s not there and apparently there are no plans to include it in future software upgrades. Wether this info is needed or not is a debate that I don’t need to get involved in, I want it so that’s all that is of interest to me.
 
Don't disagree, I would love to have one it would be very useful. However unless my boat came with one already fitted, I don't think i could ever justify the cost, not to swmbo anyway /forums/images/graemlins/frown.gif
 
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