you seem to go on about this VW505.01, might seem a bit silly but what is it? is it like a VAG stamp of approval? my toledo just gets the cheapest oil about which has some consistency to it.
i`ve run a lot of VW`s over the past 7 years now ranging aircooled classic to modern watercooled and, none of them have ever batted an eyelid at what oil was in them. I know my old vw type 3 i had many years ago, used to get run on £4.99 redstar oil, mainly because it would leak so much. my mk1 golf got 7.99 oil and 12.99 oil and again no difference to running, and my toledo just gets what evers left.
im to scared to do a service on my toledo, it hasnt been serviced in about 3 years and done 65k miles since last, just get little chance now, but being a vag engine it just keeps going and going.