Are you wondering which engine oil you should use in your four-stroke outboard? Using oil approved for your engine will improve performance, protect your engine and make it last longer. Marine engines require oil designed for wet, harsh conditions. Fortunately, the National Marine Manufacturers Association (NMMA) has a certification program to help you determine if the oil you are using delivers enough protection for your marine engine.

What is NMMA?

NMMA is the nation’s leading trade association representing manufacturers of boats, marine engines and accessories. It is the voice of the recreational boating industry. The NMMA oil-certification program is intended to help boat owners recognize the NMMA-certification trademark and understand that oils displaying such trademarks are backed by a reputable association.

NMMA Four-Stroke Certifications

NMMA has many product certifications, two of which deal specifically with four-stroke marine engines, which are: Certified FC-W oils and Certified FC-W (CAT) oils. FC-W stands for Four-Stroke Cycle, Water Cooled Gasoline Engine Lubricant. NMMA certification indicates an oil has been tested by a certified laboratory and NMMA has issued a license for that oil’s formulation and it registers the approved brands that have been tested.

What is Tested?

Before an oil can be certified by NMMA, viscosity, corrosion, filter plugging, foaming and aeration are all carefully analyzed to ensure the oil is properly formulated for marine use. Additionally, certification includes a 100-hour general performance engine test to meet NMMA qualifications.

FC-W Trademark

NMMA recognizes that marine engines face unique demands compared to non-marine engines. In addition to exposure to humidity, freshwater and saltwater, marine engines are often run at high speeds under heavy loads and are subjected to jarring waves. To thrive in such conditions, marine engines are typically engineered to be more powerful than non-marine engines. An FC-W trademark indicates that a lubricant meets the performance and quality standards necessary for today’s high-performance marine engines.

FC-W Catalyst Compatible

For some time, reducing emissions produced by marine engines has been a top priority of engine manufacturers. Four-stroke marine engines have been designed, engineered and built with technologies and components that produce fewer emissions, including the use of catalysts. Protecting catalysts in marine engines places additional demands on engine lubrication. FC-W (CAT) indicates that a lubricant meets the performance and quality standards.

Choosing the Right Oil

The next time you purchase marine-engine oil, select an oil that displays NMMA trademarks to ensure it has been tested and approved by the National Marine Manufacturers Association.

Choosing the right oil is one of the most important things you can do to protect your investment.