Best Oil for my Blue Motion Golf Mk 7 2018?

[ZeroZero]

Can people please advise on the best Oil for my Blue Motion Golf Mk 7, 2018? I used to use Castrol Professional (synthetic) and this gave a significant improvement (rougly 3 mpg) in mpg over the oil when car was new. This seems to be defunked and replaced with Castrol Edge.
There are many different rtypes of Edge, with different numbers after them. Can anyone explain rthese numbers which one is right?

Thank you all
Z

 

[tigeo]

What does your manual/underhood sticker say w/r to the oil approval required for your car? Approval here not viscosity is what I'm asking.

 

[golfdave]

What engine is it??...petrol, diesel, size, etc??