Just remember, unless you fix the needle position the zero will never be zero
We’ll see. 0 was below the empty line before. Problem was 1/8th tank to zero was about a gallon instead of the 3 or so it should have been. So rescaling should shift it over enough.
There are about 30 or so points on the empty side that read zero but still reference a voltage and about 90 on the full side that read 100 but range from~2.5 - 5 volts so they allowed room to move it over some as needed.
I have it dialed fairly close to accurate from 1/2 tank to full based on where the needle was and the volume I put in when filling. Now I need to fill a fuel jug up and drive around till it runs out to see how close I am on the empty side.
Below are some snips of the stock table vs what it looks like after I adjusted. Before the needle would not move for 100 miles and then it would drop to 3/4 tank in about 10 miles. This was how the stock table appeared to be set - jumped from 66.27-100 in .02 Volts. By extending the ramp up and moving the 100 value over it smoothed out the drop and moved the needle back to the full instead of 3 needles over full. I'm hoping there's enough room on the empty side to do the same if needed.
You are correct though, if the voltage isn't enough or bounces around too much to be reliable on the empty side I will have to pull the needle off and move it.