Quicksilver Premium Gear Lube is a marine-specific gear lubricant designed to protect the lower units of outboard and sterndrive engines, especially in applications below about 75 hp. It uses an 80W-90 viscosity formulation with a specialized additive package that provides excellent protection against excessive wear, corrosion and pitting, and helps guard gears if water enters the housing — a common concern in boating environments that automotive gear oils aren’t engineered to handle. This premium marine gear lube reduces friction, supports smooth shifting, and helps extend the life of gear components through stable performance across typical marine temperature ranges; regular service with it (usually once a year or per hours of operation in your owner’s manual) is key to keeping your lower unit running reliably.