You likely didn’t see my previous post, in another thread. I recommended a 5w40 diesel oil. An oil that carries approvals such as Ford’s F1, Cummins CES 20086, or one approved for the GM 6.6 Duramax. None of these diesel “truck” engines approve ESP. For example, VPBE 5w40 carries the following approvals:
Cummins CES 20086
Mack EOS-4.5
Volvo VDS-4.5
Caterpillar ECF-3
Detroit Diesel DFS 93K222, DFS 93K218
Chrysler MS-10902
Ford WSS-M2C171-F1
ACEA E11-22, E7-22
MAN M3775. M3575, M3275
Daimler Truck DTFR 15C100 (228.31)
MTU Category 2.1
This oil, for example, is specifically formulated for diesel trucks, not for diesel “grocery getters” that require a 0/5w30 viscosity grade. This is the point I was trying to convey, which is related to my initial suggestion of 5w40 for his truck. Once more, considering fuel dilution and engine oil operating temperatures, I believe using 5w40 will enhance engine longevity.