Always worried about the accuracy of the oil temp gauge since it was an older gauge with a newer sensor.
It is spot on from 212 F to 180 F. Below 180 it is off by about 10 deg as it approaches the 120 mark.
I used a known good thermometer as a control that does read exactly 212 F (@ boiling point)
I would imaging from 212 F to 250 F the accuracy would be at least +- 5 deg or better but I can't test that high unless I want to but it in hot oil.