I use 5w30 Castrol LL03 diesel oil from the local VW dealership in my tractor and generator engines. In future, I'll see if I can find 0w30 M1 ESP for less than what they charge me. It would be even better.
I once owned a VW Cabrio with hydraulic lifters. Apparently one of them would drain its oil down a little when shut down. Every startup would produce a hydraulic valve knock that they produce when empty unless I used 0w30 (don't think 0w20 was available back then). Even 5w30 produced a couple knocks. The oil pump just picks the oil up quicker the lower that 1st #. All oil is thicker than that last # on startup, no matter what the first # is.
10w30 is probably not much more than bar and chain oil with a few additives, about what the old plain 30w was.
Ralph
