They use it and Hyundai requires it are 2 different things. However my understanding from posts here 0w20 is always "synthetic" (correct me if I'm wrong). So if Hyundai is stamping 0w20 on their oil caps now then that can be why?
07 Acura TL Type S 6MT - PP 5w30/Fram Ultra XG7317
07 Acura RDX - PP 5w30/Bosch 3323
07 Honda Accord Hybrid - M1 5w30/Bosch 3323