Don't get sidetracked with the MPH calibration until you get the SG WORKING PROPERLY.
"Okay. next time I fill up I will post back on here. Last I remember the gallons didnt do anything it was on 0 and I remember the percentage was like 96%"
I didnt even think this was possible. If this is , in fact , the case, you have the SG so jacked up that it is not telling you much of anything. NEXT TIME YOU FILL UP :
1. Fill tank
2. Start truck
3. When SG comes up, PRESS RED CIRCLE BUTTON
4. Press button next to MORE
5. Press button next to FILL UP
6. Take picture of screen. It should be a number near what you would expect depending on what your fuel gage said when you stopped for gas.