I like forums  because its like a "head up" on trends, but because of recall bias, they tend to over report failures, making normalization critical.  Its the problem of "the denominator".

I agree through - when there is a problem, just fix it  and quit trying to study it.  Its just we cannot assert there is a problem yet.   I am especially suspicios because EVERY engine maker takes heat with new engines, and now everyone states the EVERY tier 4 from EVERY supplier is junk- without ever even owning one.  I think there has been a mob mentallity brewin, I am highly skeptical they are acting on good information.