Quicksilver Premium 80W-90 Gear Lube – Protection for Lower Units up to 75 HP

Quicksilver Premium 80W-90 Gear Lube is engineered to provide reliable protection for the gearsets in small to mid-range outboard engines and their lower units. Its formulation is optimized for smaller gearboxes that operate under lower loads but still face typical marine challenges – exposure to water, corrosive environments, and variable loads. Premium 80W-90 helps prevent excessive wear on gear teeth by ensuring a stable oil film between them during operation. As a result, the gearcase runs smoother and quieter, and the risk of costly damage is reduced.

A particularly valuable characteristic of this oil is the inclusion of special emulsifiers and inhibitors that protect the gearcase in the event water enters. Marine gearcases may sometimes get a minor amount of water ingress due to worn seals or temperature cycling. Quicksilver Premium Lube is formulated to emulsify this water and continue lubricating effectively rather than separating and leaving gears unprotected. This translates to added security against rust and pitting on gear surfaces.

Quicksilver Premium 80W-90 is produced directly by Mercury Marine, adhering to the manufacturer’s original quality standards. It outperforms ordinary automotive differential oils, which are not designed to withstand constant high humidity and hours of high-RPM operation. Mercury ensures that with Premium Gear Lube, your engine receives the proper care recommended in service documentation – an important factor for maintaining warranty and peak performance.

Typical use cases:

• Lower units of Mercury/Mariner, Yamaha, Tohatsu, etc., outboards up to about 75 horsepower where 80W-90 / GL-5 oil is recommended
• Small fishing boats, inflatables/RIBs, and runabouts powered by 2-stroke or 4-stroke motors up to 60-75 HP – Quicksilver Premium provides appropriate protection for everyday use
• Sterndrive systems (MerCruiser Alpha One, etc.) under moderate loads or older models for which Mercury recommends Premium Gear Lube instead of High Performance
• Annual gear oil change during winterization or pre-season prep – Premium 80W-90 is the right oil for standard conditions and moderate duty
• Boats operated in inland waters (rivers, lakes) or nearshore where engines are not under constant extreme stress – this oil offers an excellent balance of protection and value

Instructions & Maintenance:

• Changing the gear oil with Quicksilver Premium 80W-90 is straightforward: remove the lower drain and upper vent, drain the old oil, and fill from the bottom up with a pump until oil appears at the top hole. Replace the top plug, then quickly the bottom plug, and clean up any spills. Use new seal washers on the plugs to prevent leaks.
• Check the oil level and condition at least once during the season. If you notice a milky color (a sign of water), replace the oil and inspect seals. Premium Lube will protect in the short term, but always address the cause of water ingress.
• Under normal use (weekend cruising, casual fishing), changing the oil every 12 months is sufficient. If the boat sees heavy use or has been stored for a long time, do not skip this change – fresh oil ensures optimal protection.
• Do not mix Premium 80W-90 with High Performance (SAE 90) Gear Lube or other types – if switching oils, drain out the old completely. Premium Lube has a distinct formula tailored for lower horsepower applications.
• Environmental note: Collect used oil in a sealed container and bring it to a recycling facility. Never pour old oil into water or soil.
• If you have an engine above 75 HP, consider Quicksilver High Performance Gear Lube SAE 90, which is formulated for higher stress. But for smaller engines, Premium 80W-90 remains the top choice for easy running and dependable protection.