Other Fuel System Tank Filling/charging problems of the 2015 Hyundai Sonata

1. Cruise control is jerky and rough on acceleration and deceleration 2. Main issue I have with this car is that the fuel gauge is incredibly inaccurate. If it reads at 1/8 tank, I can only put in 12-13 gallons. Each "tick" mark on the gauge value ranges from about 9 miles to 63 miles despite the fact that it regularly gets 32+ mpg combined city/highway. When I complained to the dealership (I bought it used) they replaced the vaccuum cylinder, which helped with filling the tank (it would previously just shut off mysteriously during fill-ups) but then the gas gauge measured even worse. The "range" as calculated by the car's computer is always very low and drops off precipitously even though I know (by the trip meter) that I haven't gone far enough to have used as much gas as it would appear. Despite the obvious flaws of the gauge, the codes still read that it is working "normally" and to have it covered by the warranty, I have to experience a complete failure of the fuel sending units, I. E. Catastrophic break down. I would like to have them replaced before it gets to that point.