because your displayed miles are the BMS guessing at your pack capacity. All it's doing it taking voltage readings at different SOC. It can't really tell how much capacity the battery has unless it's full. The more areas you let it take measurements the more accurate it's guessing is. With the 3 and Y it's 3 hours of sleep before it takes these measurements.I consider it something and significant if it continues degrading at this rate. I’m just trying to understand the root cause of the sudden change because I expected degredation to be slow and steady.