Quote Originally Posted by MIRSAD View Post
Which oil can be used to top up before doing your first service or more specifically....
is it good idea to top it up with synthetic oil like Castrol SLX III 5W-30 : (found at VW dealers)

It is not for GTI (service done on 8.5K km) but for 90TSI (7,800KM 7 months old)
for a top-up, any 502 or 504 spec oil. if you call in at your dealer, they will do it for free