PETG Temp tuning tower

Ive recently switched to using PETG from PLA filaments. usually print at 240deg and 80 bed but white PETG filament seems to fail on every print, its dry , Just out of the packet, other colours of the same brand printed fine just cant get white to work consistently, redid PA and smoothing setting, and have just done a temp tower ranging from 260 deg to 220, its changing temp where it should, I watched it but there's barely any difference in the results at differing temps. Should there be ? Seen pictures of other peoples towers and they go from fail through good to fail. Is the temp range not large enough in mine ?