I have 2 temperature sensor, one in the head which feeds the ECU, and one in the coolant pipe as it exits the thermostat, which feeds the dash gauge.
The dash gauge varies quite a lot, but usually shows around 90C in normal driving conditions. The ECU reports a rock steady 100C under more or less all conditions.
I would imagine that the digital temperature readout on the ARP4 could be similar, reporting the temperature in the head, whereas the gauge shows the coolant temperature as it circulates.
