My OEM gauge always reads high when the motor is cold. The pressure will also read higher when the motor is spinning higher RPM's (foot on the gas), and very low at idle.
It has read this way with the 3.0 and now the 3.4 I have in there. Mind you, same sending unit and location is used for both motors.
I have heard that the OEM gauges are notoriously inaccurate though.
I realize this info doesn't answer your question directly, but you at least now know the pattern of another gauge is different from what yours is showing.
Whether this is bad or good... I am not sure.
