Just out of curiosity, every car is designed with their own specs. The oil it uses are also tested by the engineers.

For example, Perodua have their own engine oil designed for their car. Does using a "better" oil benefit the engine?

I have also heard of things like engine oil designed for Asian cars or Continental cars. Is there really such a thing?

From my personal experience, I think having the correct viscosity is more important than getting an oil designed for your car. Provided it's not fake eh.