Servo Transmission C4 fluids are formulated to meet TES-228 specification and approved by Detroit Diesel Allison Transmission Division of General Motors, U.S.A as a service lubricant for on-highway and off-highway Allison Heavy Duty Automatic Transmissions. These C4 fluids meet severe oxidation stability and have superior Non- Asbestos clutch friction tests, fluoro elastomer seal compatibility and more demanding anti-foam and anti-copper corrosion requirements. Due to superior perfor- mance level, these fluids give trouble free longer drain period.