JASO ATF S-1

JASO ATF S‑1 is a Japanese standard that defines the requirements for automatic transmission fluids, including viscosity, thermal stability, oxidation resistance and friction properties needed to ensure smooth shifting and gear protection in automatic transmissions of motorcycles and scooters. The specification calls for a stable viscosity at 100 °C ≈ 3.5 cSt, high resistance to breakdown under high temperatures and retention of friction characteristics throughout its service life. Fluids that meet JASO ATF S‑1 are suitable for engines with automatic (including CVT) transmissions installed in modern motorcycles, scooters and some passenger cars with similar transmissions, especially in Japan and markets where this technology is used. They are compatible with catalysts and DPF systems because they do not contain high levels of SAPS, allowing avoidance of particulate filter fouling. When selecting XENUM products, the JASO ATF S‑1 mark guarantees that the oil meets these requirements and can be used without risking the manufacturer’s warranty.