- Joined
- Dec 30, 2022
- Messages
- 250
The manual makes perfect sense. 5w-x for colder temps & 10w-x for hotter temps. You're looking at the high end 30 vs 40 but that is not what cummins/Nissan are looking at. They are putting more emphasis on the starting temp viscosities 5w vs 10w. I suffer from the same issue...overthinking.
dude they recommend the 10w-30 for CAFE reasons..
The manual doesnt do a good job at explaining things..
the reason owners manuals dont expound upon certain things is because it opens up more questions.
5w-40 will do a better job at carrying away a wear particle to the oil filter.