I have read a bunch of posts both here and on other websites talking about how 0w-20 almost always outperforms 5w-20 (except in a hot running engine) in terms of engine wear because it flows so much sooner to coat the engine's parts thereby making for a shorter interval of oil starvation, especially when the weather is cold. Makes me want to switch both of my current cars from 5w-20 and 5w-30 to the zero weight versions since I want to extend the life of both as much as possible. Got me thinking however about VW and certain other cars that still recommend a lot of 5w-40. The 5w-40 has got to flow a whole lot slower than 5w-20 or 5w-30 and yet VW engines supposedly last about as long as others all of which use thinner oils. Doesn't make sense. How is this possible? Makes me wonder whether all the hype about how much better the 0w oils are has any substance to it. What do people think? How do 5w-40 engines survive given that the initial oil flow has got to be a lot less than in those using lower viscosities?