Originally Posted By: OVERKILL
Originally Posted By: tig1
Originally Posted By: CT8
The Mobil 0W-40 is a far superior oil to the EP.
In what way? Different for different engines, but superior? I don't think so.
I would have to agree with CT8 that, all things equal, the 0w-40 is a superior lube. This is due to the higher level of AW additives allowed by both the grade and the fact that it is a Euro oil, as well as the more difficult to obtain Euro approvals.
Now, does that mean it is offers a tangible benefit in the OP's application? Probably not. But it is possible the different chemistry and blend characteristics have resulted in different acoustics.
What I mean is if an engine calls for 0-20EP, then 0-40 may give inferior results to the 0-20EP. Same with an engine calling for 0-40. If you use 0-20EP you may have an inferior result with 0-20EP. It's not apples to apples.