one quart of 75W 90 synthetic gear oil. 75W 90 Synthetic GL-5 Gear Oil Lubricant, is designed specifically for Volvo Penta sterndrives. This 100% synthetic oil reduces friction for longer gear life, higher torque and sustained horsepower. For late-model Volvo Penta sterndrives, including SX, DP-S, DP-SM, XDP, DPX and IPS units.