MCR
Veteran Member
I think you have this backwards. What is much more likely is that the engineers know the new oils are better, so they've reduced the margins (higher contact stresses, smaller components) and *required* the use of the better oils. In my opinion, you would be *crazy* to use an old oil.Well, the point I tried to get across is simply this, seems that "we" have the impression that the metal in our TDIs (trannys too) is different than that used in, say, a 25 year vehicle. Where in fact, if anything, it should be better. Thus, the oil of yester-year should work just fine in some applications. And further, the more improved modern oils should work even better. I think the GL-5 is a modern oil.