Gauge Summary And Thermostat Question.

[1FstGPa]

We just came back from a five state road trip with our 2020 Ram 2500 (6.7L) pulling our fifth wheel. Incredible journey! During this road trip, I had the readout set on "Gauge Summary" that displays Coolant Temp, Transmission Temp, Oil Temp & Oil Pressure. Somewhere, down the line with surfing the www, I came across several comments claiming the Oil Temp summary was more of an 'estimate' than actual temp. To me that seemed doable, since I've seen the temp jump up and cool down at an incredible difference.

However, the Coolant Temp summary and the gauge seem pretty close and the readout shows the temp dropping or rising at a convincing rate. Not all-over the map like the Oil Temp. My question, is everything on this Gauge Summary an estimate? Because this too was reading everywhere from 182 to 215 - depending on the circumstances of the road (flat to grades) and ambient temperature (high 90s to low 60s).

Which leads me to my last question and that is - What is the manufacturer's thermostat opening rated at for a 6.7 Cummins? I find it hard to believe that it would drop below 190 and yet it did on a 70 degree day pulling the fifth wheel on a flat road.

Very confused on this one!

 

[H3LZSN1P3R]

The oil is the only estimate apparently (i find it very possible for it to be a true reading as the oil temp moves with coolant temp as my old manual gauges would read on older trucks) the t-stat is 190* open, with the massive rads in these trucks its not hard to believe the temps will fluctuate below the t-stat opening slightly
Mine will stick at between 88-95*C mostly (equals the same range as yours) loaded or not….

 

[Brutal_HO]

I thought it was just the Oil PRESSURE that was an estimate derived by the ECU.

 

[H3LZSN1P3R]

I thought it was just the Oil PRESSURE that was an estimate derived by the ECU.

Would oil pressure not have its own sender like it has for decades? It would seem strange to me if that is the case, stranger things do happen though

 

[Brutal_HO]

Maybe they changed it for the 6.7L. I had heard it was the same as the 5.9L but now I'm not sure as I haven't yet found a good source.

03-07 simply used a 5 PSI pressure switch and fake numbers based on RPM and temp.

 

[H3LZSN1P3R]

Maybe they changed it for the 6.7L. I had heard it was the same as the 5.9L but now I'm not sure as I haven't yet found a good source.

03-07 simply used a 5 PSI pressure switch and fake numbers based on RPM and temp.

Very interesting, i have never actually checked on my 05