AH64ID
TDR MEMBER
AH64ID why did you run 15-40 on current that is "0" and above but on the new 22 you are going to run the below "0" oil. Seems to contradict?
The way I look at it why have a "0" and above option if the below "0" and above is fine?
Not contradicting at all, it’s about the oil specs and understanding what all the specs mean for engine protection.
In my ‘18 I run the same oil you current do, a full synthetic 15w-40 with a -40° pour point. That’s within 5°F of many 5w-40’s, which is plenty and has some benefits over the 5w as well. Since the warm viscosity is the same there is similar protection under hot/heavy operating contortions, but the 15w has a lower NOACK volatility and a better high temp/high sheer rating. That made the 15w-40 full synthetic an easy choice over the 5w-40 full synthetic.
As you know the 15w-40, synthetic or not, is not an approved viscosity for the 19+ trucks. That leaves the 10w-30 vs 5w-40. While the 10w-30 has the better NOACK volatility rating the 5w-40 has a better pour point, better high temp/high sheer ratings, and holds viscosity better when hot. So that makes it an easy decision to run the 5w-40 over the 10w-30.
I was just made aware of Shell Rotella T6 Full Synthetic Multi-Vehicle 5W-30 Diesel Engine Oil, does anyone know if we can use this in the 6.7 its rated CK-4?
There are several 5w-30 CK-4 diesel oils. They should be fine for the application, but if you are still under warranty it wouldn’t hurt to have a conversation with your service advisor.