Mercury Antifreeze – -50°F, 1 Gallon | 8M0073201

Mercury Antifreeze – -50°F Marine Water-System Antifreeze | 8M0073201

Protect your marine engine and onboard water systems from freeze damage during winter storage with this genuine Mercury OEM antifreeze. The ready-to-use propylene glycol formula circulates through raw-water cooling passages, livewell systems, and boat plumbing to displace water and prevent freeze expansion that can crack engine blocks, pumps, hoses, and fittings. The bright pink color makes it easy to confirm the antifreeze has fully circulated during winterization.

Compatible Applications

• Mercury outboard engines — 2.5 HP through 400 HP (FourStroke, Pro XS, Verado)
• MerCruiser sterndrive and inboard engines — 3.0L, 4.3L V6, 5.0L V8, 5.7L V8, 6.2L V8, 7.4L V8, 8.2L V8
• Raw-water cooling systems on any marine engine
• Livewell and wash-down systems
• Freshwater plumbing on boats
• Not for use in closed-cooling (freshwater-cooled) engine systems — those require engine coolant, not water-system antifreeze

Part Details

• OEM Part Number: 8M0073201
• Mercury Reference: 92-8M0073201
• Brand: Mercury / Quicksilver
• Product Type: Marine water-system antifreeze
• Formula: Propylene glycol — non-toxic, ready-to-use (no dilution required)
• Burst Protection: -50°F (-46°C)
• Freeze Protection: Approximately 12°F to 16°F (-11°C to -8°C)
• Container Size: 1 Gallon (3.78 L)
• Color: Bright pink
• Condition: New OEM

Service Interval

Use during annual winterization before storage in freezing climates. Flush and replace with fresh water at spring commissioning before returning the engine to service.

Technical FAQ

• Is this the same as engine coolant? No. This is a water-system antifreeze for raw-water cooling passages and plumbing. Closed-cooling systems require a separate engine coolant. Do not use this product in a closed-cooling system.
• Do I need to dilute it? No — this is a ready-to-use formula. Use it straight from the jug.
• How much do I need? Quantity depends on engine size and the number of systems being winterized. A single gallon typically covers one outboard or sterndrive engine; larger engines or multiple systems may require more.
• Can I use automotive antifreeze instead? No. Automotive antifreeze (ethylene glycol) is toxic and not safe for marine plumbing or livewell systems. Always use a non-toxic propylene glycol marine antifreeze.
• What’s the difference between -50°F and -100°F versions? The -50°F version is suitable for most Canadian and northern US climates. The -100°F version provides additional protection for extreme cold storage environments.

Related Parts

• Mercury Antifreeze – -100°F, 1 Gallon | 8M0073203
• Mercury Antifreeze – -100°F, 55 Gallon | 8M0073204
• MerCruiser Fogging Oil – 858081K03
• Quicksilver Rust Guard Rust Inhibitor – 858081KC3

Parts Desk Insights

This is the go-to antifreeze for winterizing raw-water cooled outboards and MerCruiser sterndrives in climates where temperatures drop below freezing. The most common mistake is confusing this with engine coolant — this product goes into the raw-water side of the cooling system, not the closed-cooling circuit. A second common error is under-buying: one gallon is usually enough for a single engine, but if you’re also winterizing a livewell, wash-down pump, or freshwater system, plan for more. Always run the antifreeze until you see pink coming out the exhaust or discharge point to confirm full circulation. Pair with fogging oil for complete engine storage protection.