Golf GTDs come with VW 507 00 spec. Either Castrol Edge LL-3 5W30
or Shell Helix Ultra Professional AV-L 0W-30. European built gasoline
engines have the exact same factory fill*. Very most definitely. Both
of these oils are excellent quality. Save money, order online.
That said you can mix every common engine oil. There's absolutely no
need to top up with the exact same oil. Just make sure it comes with
an official VW 507 00 approval. It's not suffcient that the manufacturer
recommends it for your car. This approval (like most) demands that the
can be mixed with any other oil of that spec at least without losing it's
properties that have been mandatory to meet this spec and get VW's
approval. There's definitely to reason to worry.
*It just says VW 504 00 for gasoline engines, however any oil meeting
VW 504 00 simultaneously also meets 507 00 and vice versa.
Starting with MY2018 some Golf engines are factory filled with 508 00
spec oil (0W-20). Just to be complete, it isn't relevant for your GTD.