Can someone explain how to set-up / use Smartcraft Fuel Used?

[BamaBass99]

Can someone explain how to set-up / use Smartcraft Fuel Used?

[MakingWaves]

So I use Smartcraft at all times to verify how much gas I have in the tank. If you know your tank holds 50 gallons, fill up the tank at 100% and reset the gauge to show zero gas used. At the same time of the fill up I'll put a note in my phone that on that particular day I put in 50 gallons. Say a month from then it shows I used 30 gallons well then I know I have 20 gallons left. Anytime I add gas I reset the smartcraft gauge to zero and change the note in my phone. It is very accurate but I did learn the hard way that at 5 gallons left in the tank my motor will not run because the sending unit in the tank must be a little higher than I thought.... Had to use the TM for the last half mile. Hope this helps.

[SilverFox579]

Yep, just that easy. Zero "fuel used" after filling the tank, afterward, the fuel used displayed will be within 2% of actual consumption. Depending which SmartCraft gauge you there may be other fuel used options.

[BamaBass99]

So I use Smartcraft at all times to verify how much gas I have in the tank. If you know your tank holds 50 gallons, fill up the tank at 100% and reset the gauge to show zero gas used. At the same time of the fill up I'll put a note in my phone that on that particular day I put in 50 gallons. Say a month from then it shows I used 30 gallons well then I know I have 20 gallons left. Anytime I add gas I reset the smartcraft gauge to zero and change the note in my phone. It is very accurate but I did learn the hard way that at 5 gallons left in the tank my motor will not run because the sending unit in the tank must be a little higher than I thought.... Had to use the TM for the last half mile. Hope this helps.

Very helpful. Thanks. So to reset you hold the Troll - and Mode button correct?

[MakingWaves]

Very helpful. Thanks. So to reset you hold the Troll - and Mode button correct?

Honestly without looking I can't remember but I'm certain you have to hold two buttons down to reset. Hold down for a couple seconds and it will go to 0.

[SilverFox579]

Reset procedure will depend on which specific Smartcraft gauge you have (there are several).

[5keepers2]

Just so you know not all Smartcraft gauges are accurate. Mine understates 16%. I been using it for 5 years and I went only by it I would run out of gas. If it says I burned 10 gallons I know to put 11.6 gallons back in. I still like it and use it every trip. The gauge has no adjustments.

[gehol]

So I use Smartcraft at all times to verify how much gas I have in the tank. If you know your tank holds 50 gallons, fill up the tank at 100% and reset the gauge to show zero gas used. At the same time of the fill up I'll put a note in my phone that on that particular day I put in 50 gallons. Say a month from then it shows I used 30 gallons well then I know I have 20 gallons left. Anytime I add gas I reset the smartcraft gauge to zero and change the note in my phone. It is very accurate but I did learn the hard way that at 5 gallons left in the tank my motor will not run because the sending unit in the tank must be a little higher than I thought.... Had to use the TM for the last half mile. Hope this helps.

You may be exactly correct but, I understood it a little different. You are saying the digital fuel used, uses the change of level in the tank to get its information. Mine has a digital fuel flow along with fuel used. The fuel used seems to get its information from the fuel flow and is a simple totalizer. I will have to check into this a little closer.

[EuropeanAM]

Accuracy will depend on the engine. Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (Serial Number) when posting. Thanks!

The information for "fuel used" comes from the base MAP tables in the PCM based on what those tables demanded for fuel delivery. However, some fuel TRIM features of the V6-V12 Fourstrokes fall outside that MAP information and are not accurately reflected in the "fuel used" reporting.

[gehol]

That is what I thought, thanks for the clarification, Don.

[Capt James]

So I use Smartcraft at all times to verify how much gas I have in the tank. If you know your tank holds 50 gallons, fill up the tank at 100% and reset the gauge to show zero gas used. At the same time of the fill up I'll put a note in my phone that on that particular day I put in 50 gallons. Say a month from then it shows I used 30 gallons well then I know I have 20 gallons left. Anytime I add gas I reset the smartcraft gauge to zero and change the note in my phone. It is very accurate but I did learn the hard way that at 5 gallons left in the tank my motor will not run because the sending unit in the tank must be a little higher than I thought.... Had to use the TM for the last half mile. Hope this helps.

About 10% of a fuel tank is not usable. The fuel pickup is usually about 1" above the tank bottom, given the length of a boat fuel tank and sloshing of fuel, usually this amounts to about 10%

[gehol]

We have got two conversations going here. The information below assumes a V8 four stroke.
Concerning fuel level; You can use the fuel used to estimate the fuel left in your tank as long as you know how much fuel was in the tank at reset. To me that is a crude way to get that information. Your smart craft has a window that gives per cent remaining in tank, regardless what was in the tank to start. All you need to know is how much your tank holds and check calibration of the "percent" function. In other words at empty, half tank and full does the percent left in tank appear accurate. An example; You have a 50 gallon tank and the "% remaining" window shows 25% remaining, you know you have 12.5 gallons left regardless of how much you had to start with. You just have to make sure your fuel level is calibrated correctly which is simple.

Now, lets talk about fuel used. First what is its intended use. It will show you the amount of fuel used since last reset. Very simple and is all it does. One example of where this might be useful. You and a buddy have a 5 day fishing trip where it was agreed to split the fuel used in the boat. You may not want to start with a full tank for a variety of reasons. So what is the easiest way to keep up with fuel burned. Set the fuel used to "0" before launching boat. Put ever how much gas you want to each day but leave the "fuel used" alone. On the last day of your trip during loading, check fuel used and that will be the total amount of fuel for the 5 day trip that was used.
Second where does that information come from. As Don explained it has nothing to do with the level in the fuel tank. There is a MAP table in the PCM that tells the PCM how much fuel to inject based on air flow and perhaps some other parameters. Manifold pressure, air temp, throttle position may or may not be considered (Don may give us some info). Anyway the PCM will call for an amount of gas to agree with the tables.
To get fuel used, the actual flow called for is read many times per second and Mercury has an algorithm that turns that sampling information into fuel used. A note: Don said on the bigger motors the algorithm may not work well due to fuel flows, especially at WOT, that might exceed the upper limits of the algorithm.
Hopefull this will separate the two conversations and help the OP.

[MakingWaves]

About 10% of a fuel tank is not usable. The fuel pickup is usually about 1" above the tank bottom, given the length of a boat fuel tank and sloshing of fuel, usually this amounts to about 10%

Thank you, that is what I was trying to explain.

[EuropeanAM]

I've removed the inaccurate info regarding sending units and fuel feed. Let's keep this thread to the OP'ers engine and question: No other boats or engines, please.