DEcosse
If it's no Scottish it's CRAP!
I doubt we can ever know that - and whether that is a 'real' number anyway to whatever reference they might be suggesting.
So again, with FuelBot, whatever the maximum fuel you ever manage to squeeze in there, to use as the overall capacity, you will be confident in consistently being able to reach that zero point.
It doesn't need a GPS to predict with any more accuracy than the std speed sender - although the speed indicated is quite optimistic, the odo should be quite accurate.
However you can choose to calibrate the distance against your gps or simply the OEM odo - whichever you use it will predict the remaining range based against that reference. The best reference is volume remaining - range remaining will vary based on current consumption rate but capacity will be whatever it is.
If you calibrate the distance part against your OEM odo, then the range remaining predictor will be as accurate as that reference.
One interesting thing is that I have a speed healer device for my speedo; so while it now gives accurate speed, my odo is about 9% low.
However I can calibrate the FuelBot odo to reflect the REAL odo rate;
so over 100 miles, while my speedo says it is only 91, my FuelBot actually says 100.
And it doesn't matter whether I source the signal BEFORE or AFTER the healer device, I can still calibrate the FuelBot odo to be accurate.
With the R3's Keihin ECU, you can actually make the correction to the OEM speedo display using TuneECU
Note that if you calibrated the FuelBot initially, prior to a TuneECU correction factor, the two would now be different and the Fuelbot would retain its original calibration and read accurately while the Speedo would be low if it was calibrated to match GPS speed.
For most us, we will probably be content to use the factory stated capacity or have a SMALL reserve beyond the nominal stated spec capacity. (Although I think generally the stated volume is low already with respect to the actual volume to the neck, so you already in essence have a small reserve by entering the factory spec number)
But if you want it super-accurate down to the 100mLs (or less!) then read on
What you could do is - put in a higher than actual capacity (let's say 30L) - run it to splutter as you suggest - put 10L in BUT DO NOT RESET IT; however note the capacity it currently states has been consumed
then regardless of how far you need to go to the gas station, you have four references
1. The 'used' capacity it had consumed to the splutter point
2. The 10L added
3. The volume consumed between the splutter point and the gas station refill
4. The new volume to fill the tank
From 4, you then deduce what the net fill from zero would have been - this is the new fill PLUS the 10L MINUS that consumed between filling the 10L and reaching the gas station
That new number should also equal that from '1'
Example
Note that you should first do the std consumption rate cal at whatever volume you elected to put in there initally; so that part is already established;
then to get accurate tank 'volume';
Start with your tank filled to whatever your preferred full reference level on sidestand might be;
Set tank volume to 30L;
Reset to zero/full;
Run to splutter (let's just say it indicates you have USED 25.6L so it will also say you have 4.4 left) (you can call it done here and just restate your tank volume as 25.6)
Additional check
At that splutter point fill 10L
continue to gas station where it now shows consumed amount is 27.9 - which means you used a further (27.9-25.6) 2.3 L since your splutter stop/10L fill
You then fill tank to the same reference as before and it should take 17.9L
17.9 plus [10 minus (27.9-25.6)] = 25.6
So now you have TWO checks that say your tank capacity is 25.6L from your full reference to splutter.
