Hyundai and Castrol Oil

In my Accent's owners manual, it reads, "* Hyundai recommends using Castrol oil or equivalent oil in your engine."

Does anyone know the reason for this? Is there something special about Castrol, or is there some business deal between the two?

Thanks.

Business deal, but i use it cause its one of my favorites.

Try castrol synthetic blend or mobile clean 7500.