Mercury - Quicksilver 80W-90 Premium Gear Lube Marine Lubricant 8 oz Tube 802844Q02. Overview. Your lower unit does the hardest work on your boat - keep it protected with Mercury Marine 802844Q02 Quicksilver 80W-90 Premium Gear Lube. This high-performance formula is made for outboards up to 75HP and provides solid protection against wear, corrosion, and heat. It's built specifically for marine conditions, where moisture and pressure can quickly ruin lesser oils. The 8 oz tube makes filling small