Wow, getting nervous with more and more reports. Just in case, I find myself in similar shoes, I have been checking out other trucks. So, it not a last minute choice. So far all is well, however I'm only just over 19,000 KM.
I have added more temperatures to monitor, such as oil temperature to my list. So, far i notice, that the oil temperature seems to stay in the range of the Radiator coolant, unless you are towing, then there is change upwards.
Here in Alberta, there are lots of Dodge, but most are HEMI's and rest are RAM 2500, RAM 3500. Though lately, there are lots of Ford EcoBoost. Don't see too many EcoDiesel.
I sold my second vehicle and holding off until spring/summer, so that will be of help. My mileage will climb a bit faster on the truck.