Just got a 2017 RS Hatch and did my first fill-up last week.I wanted to do a few fill-ups to see if the issue repeated itself and it did. Each time i fill my tank, the gas gauge only gets to the second to the last line on the gauge before the Full line. Also, I purposefully ran the car longer on a tank than i usually do and after averaging roughly 31mpg, I got 367 miles for a completely full tank, and upon my fill-up, it only took 11.7 gallons. I dont know if this is a new things since the tank is slightly smaller than my 2014 1LT, but figured i would post on here to see if anyone else had these issues.