A parallel import 5W40 from overseas can be had at promo price with much higher performance specifications and OEM approvals than  a non-parallel import xW20 or 30 or 40.

In this context, go for this as it is double or triple bonus. I am in this segment.

If you are paying more per L for a 5W40 (probably non-parallel import)  with say < 8-9k kms oil change ......
it is not worthy it compared to a lower priced xW20 or xW30 (IF available??) meant for 'local' market, among which most of them are generally of a lower performance specifications without European OEM approvals.

Similarly paying more per L for a xW20 or xW30 (than a 5W40) is imho not worth it.