Originally Posted By: 2010_FX4
Originally Posted By: dnewton3
Rotella 10w-30 TP. I can personally attest that extreme temps and heavy hauling are within the capability of the TP.
I presume you will stick with the IOLM. As Ronald used to say ... Trust but Verify.
Run the dino 10w-30 and run some UOAs.
You'll be impressed.
Any thoughts on Rotella 15W-40?
In your area, I think it would be fine. Not sure how many cold starts (below zeroF) you'd see.
But, today's trucks with high performance injection systems, high-energy glow plugs, intake heaters, etc really makes cold starts not as much of an issue. It's not like you're trying to start an old IDI FarmAll tractor in negative temps in MN with 40 grade, after all ...
When it gets really cold outside, you're more likely to have to worry about the DEF freezing, than hard starting engine oil.
My point is this:
15w-40 dino will probably work well.
10w-30 dino will probably work well.
I have used both in extreme cold and heat, even with towing in the Rockies and canyon lands of the SW, and cannot find any distinguishable difference in wear control. roadrunner1 can attest to the same. I seriously doubt you would either.
As much as you are 100% correct in stating these trucks are your daddy's trucks, that same goes for lubes ... Trust that 10w-30 will do everything you need it to. I have seen no evidence to the contrary.
As for the topic of syns ver dinos, the thing to understand is that Ford's spec is predicated on an API concept. They require CJ-4 lubes; they don't spec base stocks. The Ford spec is met by any number of a host of CJ-4 products. Their diesel engine oil spec is also not grade specific. They "recommend" certain grades for certain conditions, but those are suggestions and not "thou shalt use" edicts.
If you want to run 15w-40 in the summer and 10w-30 in the winter, go for it.
For people who never get UOAs, then using the "recommended" lube with "recommended" OCIs makes perfect sense. And when under warranty this is a very good idea.
For those who use UOAs in a pragmatic, logical sense, then we need only concern ourselves with the "required" info. So we use a lube that meets the intended spec, and then let data tell us when to change oil. I say this because there are lubes that are not "licensed" (enter Amsoil, etc) but they still are targeted to a specific API criteria and do an excellent job when used correctly.