Saw a pic somewhere where an update XJ gauge had been checked against the scangauge ... and the 1/4 position was about 155 as XJ Wheeler mentioned.

Might want to check those thermostats arent stuck open ... or the temp sender isnt playing up ... coz the minimum, constant, running temp with a 180* fitted ... should be 180* ... unless you are seeing 180ish - 160ish flip flops of the needle.