Interestingly enough when you use the Pennzoil Product selector (in my case a 2015 RAM 1500 eco diesel 4WD 3.0) it says the recommended oil is Pennzoil Platinum Euro L SAE 5W-30 Full Synthetic Motor Oil which is not called out as being made from natural gas.
I am not an oil expert and I didn't...
Well I am kinda partial to the 2015! (I think the White ones make the most HP and Torque) :)
That said, you are at the upper limits or over with that size travel trailer for sure.
Maybe some one will correct me but I think 30K trans service sounds a bit excessive. Maybe send a sample of your tranny fluid off to a lab for sampling before you drop that kind of coin.
What kind of service are you looking to perform? The oil change on these trucks (although expensive) is really easy to do. Front and rear differential fluids are simple. The transmission service is a process but many say it is not that difficult, at any rate depending on the duty cycle it...
The million dollar question right there. its the without spending a bunch of money part that is relative. What is a "bunch of money"? The cost of an accident or major engine repair? or the cost of a high quality engine tune...
your choice.
Maybe do some towing first and see what things look like!
Keep your TT within your trucks rating and you should be fine.
It seems after market oil coolers can be challenging to install as the few that were available as a kit are no longer rally available.
The Crankshaft Positioning Sensor is a separate item and is not covered under any recalls. It is not installed along with the tone ring unless it sustained damage when the tone ring delaminates.