generally they use VW 504.00/507.00. VW doesn't specify a viscosity but they are all 5w-30. If you have a petrol motor then 502.00 is acceptable. Viscosity varies for 502.00 but a dealer would most likely use 5w-30.
It could be that your old oil had lost some viscosity & therefore the new stuff is a bit sluggish (oil has to be broken-in too) but more likely they reset the ECU back to default settings & the ECU/TCU has to relearn.
Subaru's used to feel less responsive after a service because there were air bubbles in the smaller galleries & these would transmit a false "detonation" to the knock sensors which would wind back timing & richen the mixture. It would often take ~500km for the settings to go back to optimum.
Bookmarks