HYUNDAI/KIA NWS 9638

The HYUNDAI/KIA NWS 9638 specification is the official transmission oil standard jointly developed by the automotive groups Hyundai Motor Company and Kia Motors to ensure optimal operation of their automatic gearboxes, including 6‑, 7‑ and 8‑speed automatic transmissions, CVT and DCT, as well as hybrid transmissions. Oil that meets NWS 9638 must have a stable viscosity in the range of 7.5‑9.5 cSt at 100 °C, high thermal resistance, excellent protection against oxidation, wear and corrosion, and a specific friction coefficient that guarantees smooth shifting and long‑lasting performance of friction elements. This standard is targeted at gasoline and diesel engines from Hyundai and Kia equipped with automatic transmissions, including models with DPF systems where compatibility with the catalyst is important. Using XENUM transmission oil approved to NWS 9638 ensures preservation of warranty conditions, reduces the risk of overheating and premature wear of bearings and friction discs, and maintains stable operation under high loads.