if your gauge is like mine it takes a long time to start to drop, so 50 wont have filled it and it will drop away quicker.
I can get 100 miles plus before it drops below the 7/8th line
only proper way to tell what your cars doing is Brim it, record miles, empty, fill, miles and calculate
think there is even summat on facebook that does it all for ya but i am geeky and keep my own record
Mine moves regardless of filling it quickly somehow a drinker! yet half a tank or less it does hold the needle a little longer....confusing the situation even more!
So 10miles left haven't driven it like a mad person, put £50 took me to 'full' Guage status of 390 miles. I drove nice and gently and done 79 miles it moves 3 thick lines up! I am still baffled at that! Wished I had my mk4 tdi 130 as that seemed to be better and was remapped!
Do u think it needs vagcom or is this generally how a GTD acts? Short journeys I do at min well anything between 5 to 15 miles between sites...