PETG likes 245 and you have to have your starting height and extrusion multiplier correct other wise you end up with brittle parts or over stringy parts. After my normal 2 walled square to check starting height and extrusion multiplier I print a 30x30mm 2 layer high solid square. There should be no space between the thread of plastic with good bonding between them. and when the extrusion output is correct, it will bend back and forth without snapping. I had a part that broke easier than I would have expected and thought it was a temperature issue.. but it was under extruded even though the 2 walled square measured correctly. Since that time I always print at least 1 layer of the 30x30 to make sure the threads are bonded to each other. For instance the other day, an extrusion multiplier of .90 made a correctly sized wall but the 2 layer square snap along extrusion lines.. at an extrusion multiplier of .92 the square could not be broken..