Originally Posted By: addyguy
10k km, or 10k miles?
This oil is supposed to be very stable and shear resistant, but it's comfortably a 30-weight. Not a good showing on this one aspect.
Sodium is high, possibly from a previous oil?
Just a note here:
1. This oil in this truck at 10,000Km (6,200 miles) was sheared down to 11.81 cst.
2. This oil in MY truck at 12,000Km (7500 miles) was 15.40 cst.
3. Motorcraft 15w40 CJ-4 in another UOA thread for this same 6.0L PSD engine was 11.87 cst after 5,000 miles.
So while this oil is regarded as being very sheer stable, it seems this engine will beat it up. The indication of it performing the same process (but with higher UOA numbers...) on the 15w40 seems to back that up.