Mack Trucks has introduced the Bulldog mDrive transmission fluid, SAE 75W-80, for its mDrive automated manual transmission. It’s a fully synthetic, heavy-duty lubricant, formulated to meet the Transmission Fluid 97318 specification.

Mack says its key benefits include the 75W-80 viscosity grade that maintains the fuel economy benefits of the transmission through reduced viscous churn, smoother gear meshing, and easier pumping and filtering. The high viscosity index is said to bring low-temperature fluidity for quicker starts, easy shifts, and reduced wear during cold start-ups while providing strong lubricating films at higher temperatures.

The lube is also said to have exceptional shear stability to maintains that viscosity and “outstanding” thermal durability and oxidation resistance to protect against deposit formation, contributing to long seal life and extended oil-drain and service intervals. It’s approved for up to 500,000-mile drain intervals.

The new transmission fluid is available in both five-gallon pails (P/N 9853-120550) and four, one-gallon jugs (P/N 9853-120551).