As the adoption of four-stroke engine design for watercraft has grown, The National Marine Manufacturers Association (NMMA) recognized the value of establishing specific oil specifications for this equipment. Four-stroke engine designs continue to grow in the market because they both reduce emissions and improve fuel economy. Oil performance in the challenging marine environment was a primary driver behind establishing these specifications.

NMMA’s FC-W® specification addresses the engine oil performance needs for four-stroke applications in marine environments. The requirements include a variety of evaluations relevant to four-stroke engine performance for watercraft, including viscosity, corrosion, filter plugging, foaming and aeration. Additionally, the oil formulation must pass a 100-hour general performance engine test.

With the demand to provide even further emissions reduction from combustion engines, the application of exhaust treatment systems on four-stroke marine engines has grown. This has created a need identified by NMMA to establish a unique specification which incorporates all of the basic performance demonstrations of FC-W®, and also ensures proper protection of the catalysts commonly used in exhaust treatment systems. This specification variation is identified as “NMMA FC-W® Catalyst Compatible.” It is commonly referred to in the industry as FC-W® (CAT).

Once oil formulations demonstrate the necessary performance qualities of these specifications, NMMA issues a certification system which allows certified oil suppliers to market their products with these credentials. This provides consumers confidence that they are using an appropriate quality oil to protect their equipment for use in on-water applications.

More information on FC-W® is available here.

More information on FC-W® (CAT) is available here.

*FC-W is a registered trademark of the National Marine Manufacturers Association