I had a 2004 Sonata with the V6, bought new, and the paperwork about the required maintenance interval made mention of some exotic oil additive they put in the refill at the dealer. I thought it was weird to have a OEM using an oil additive. I don't know if that same stuff was in the factory fill, or if it was just part of the dealer service schedule.
That being said, I did a change at 300 miles to PYB, then a 1500 mi OCI on a blend (I forget, maybe Syntec Blend), then finally M1 (spec weight 10w30).
I did the 'hard-core motor break-in technique' so I felt like getting all the bits out early was the thing to do, hence the ultra short first OCI.
That motor ran great last I had the car.