| abstract |
Power transmission fluids having a Brookfield viscosity of 13,000 mPa s (13,000 cP) or less at -40°C, a viscosity of at least 2.5 mPa s at 150°C in the ASTM D-4683 method, and a viscosity of at least 6.8 mm²/s (6.8 cSt) at 100°C after 40 cycles in the FISST of ASTM D-5275 comprise at least 50 wt% of 55N to 125N hydrotreated mineral oils, 5 to 40 wt% of hydrogenated poly-α-olefin oligomer, 2 to 20 wt% of acrylic viscosity index improver and other additive components. The compositions possess a combination of performance properties necessary for electronically controlled automatic transmissions equipped with torque converter clutches capable of operating in a continuous slip mode. |