You really don’t understand engine design do you. The oil has nothing to due with the mains spinning.You all keep looking for a boogeyman but failed bearings are nothing new to any engine from any brand. Clearly the bearing clearance was not so tight that a 40 weight oil would not work, when you have really tight bearing clearance you have to run thinner oil, if the clearance is not so tight you need to run a thicker oil, now that we know a 40 weight oil works fine in the ecodiesel we can also make an educated guess that a 30 weight oil would lead to bearing failure in a certain amount of engines because the clearance is to much for a 30 weight oil to properly protect the bearings.
No one knows how many ecodiesels had owners who bought the cheapest oil the could find, and as much as many of you want to believe that all oils are the same there are differences in oils even when they pass the API test to get that little API symbol on their bottle. There are oils of the same weight where one will shear and fall out of grade and another will hold up fine remaining in grade yet both passed the same API test and have the same API symbol on the oil bottle.
Passing an API test to get the API symbol on your bottle is one thing, the oil being used in real world use is an entirely different situation.
Like the man said in the bearing company video buy the best oil you can afford then buy the next better oil. In other words he was telling you the quality of the oil plays a big part in protecting the bearings. Run the cheap stuff if you want, it is your money and your truck for me I will stick with Redline and pay the extra price and know I have an oil that will out preform the cheap stuff.