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Oil and Lubricants


Did you know California required catalytic converters be put on marine engines under 500hp starting in 2008? 49 other states followed suit and required they be on 2010 production years and beyond.

This change required that the oil industry adjust the oil formulas to be compatible with the catalytic converters. One of the biggest changes was the level of zinc and phosphorus in the oils.

Zinc and phosphorus are primarily used as an anti-wear agents or as an antioxidants. The they accomplishes this by creating a protective film between parts in high pressure areas. These additives are sacrificial, which means they are used up and depleted as they do their job.

Check your owners manual for what the API Service Category was when you engine was made. The categories are constantly changing and the specifications from 1987 are not the same as 2019. Knowing what oil your engine needs will save you some costly repairs.

The FC-W symbol signifies a NMMA registered marine oil designed for four-stroke marine engines and the FC-W(CAT) symbol signifies an NMMA registered marine oil designed to be compatible with four-stroke marine engines that have an exhaust after-treatment catalyst.

TC-W3, TC stands for two-cycle. The W is merely standing in for water-cooled. And the 3 simply means that it's the third formulation of oil for two-cycle, water-cooled engines.

You can read more about marine oils at the National Marine Manufactures Association website

Marine Grease

Grease is nothing more than heavy motor oil with a thickening agent (usually soap) added. The thickener is what makes it stick to the metal it's lubricating, such as trailer bearings.

Marine grease has a tough job. Not only does it have to lubricate and protect bearings and other parts, it must withstand extreme moisture conditions, extreme to the point of being submerged in water. While marine grease and “regular” grease both have the same job, without special formulation that makes marine grease work, regular grease would simply wash out of parts leaving them unprotected and in danger of failure.

Marine grease is typically formulated with tackifiers that give it an affinity for the surface or make it more “surface active.” Basically, it makes grease stick better. Marine grease also contains additives such as corrosion inhibitors for both ferrous and non-ferrous metals to protect against rust, corrosion and pitting. A proper marine grease should have passed ASTM D1264 water washout testing. As a rule, marine grease should be used in any marine application including trailer wheel bearings, steering assemblies or any other parts that require grease

Gear Oil

Marine gear lube, unlike automotive gear lube, is formulated to emulsify water. It provides consistent lubrication, keeping water away from moving parts and seal in good condition. Careful attention and service is imperative to keep the lower unit of your boat serviceable.

Moisture in gear case oil

Transmission Fluid

For inboards that have a transmission, The manufacture has an API Service Category for the transmission fluid at the time of manufacture. Your transmission may use an automotive type automatic transmission fluid, hydraulic oil, or even engine oil. Your will find this in the owners manual .

To learn more about oils and lubrication consider attending one of our Engine Maintenance Classes


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