JASO 1-A

JASO 1‑A is a Japanese standard that defines the requirements for transmission oils for automatic gearboxes, specifically regarding their viscosity, high‑temperature stability, ability to deliver precise friction levels, and wear protection. The specification calls for a minimum viscosity at SAE 75 °C, high oxidative stability, controlled micro‑mobility of friction elements, and compatibility with seals made from polymer materials. Oils that meet JASO 1‑A are intended for automatic transmissions of passenger cars, crossovers, and light trucks, including electronically controlled systems and multi‑speed gearboxes. They provide smooth gear shifts, prevent overheating and deposit formation, which is especially important in intensive city and highway driving conditions. If your vehicle requires JASO 1‑A, XENUM XA‑TRAN UNI offers full compatibility while also meeting newer requirements that include JASO 1‑B, without loss of protective properties.