It is a hot topic but do not quite understand what they say because my English is painful and use google translator.
It is doubtful that I totally recommendations.
Castrol, Motul 5W30 recommend etc.
A couple of years opel now told me that 10W40 5W30
Now I know what to do.
My car always have put 5w50 mobil one but I like it a lot and I think something leaking turbo seals, but I'm not sure.
I change oil every 7000kilometros-10000kilometros "you?
I believe that the degree 0W and 5W is very thin and may leak, but also the 10W40 90% there are not 100% synthetic.
Do not know what to do and oil