I've been advised by the Kia and Hyundai community to swap from 5w-30 to 5w-40 in my 1.6 Turbo GDI.
Amsoil doesn't offer 5w-40 in the Signature Series. Those who run Amsoil in the Kia/Hyundai community run the European Series 5w-40. From what I gather it is the same stuff expect it has (SAPS)...
