With the widespread introduction of the four-stroke outboard engine technology, NMMA considered it necessary to develop a marine engine oil category specifically for marine four-stroke engines. With many of the major outboard engine manufacturers producing four-stroke outboards to reduce emissions and increase fuel economy, the need for oil specifically designed for the unique marine environment became necessary.
Working with the NMMA, industry leaders in lubrication technology developed testing criteria for this marine four-stroke oil. These criteria include bench tests for viscosity, corrosion, filter plugging, foaming and aeration. In addition, the oil must successfully pass a 100-hour general performance engine test.
Once an oil has been tested by a sanctioned test laboratory, NMMA issues a license for the oil’s formulation and registers approved brands.
FC-W® lubricants have demonstrated the necessary performance and quality needed in today’s high performance four-stroke marine engines. The next time you are purchasing four-stroke oil for your marine engine, look for the FC-W® trademark.
2025 FC-W® Registered Four-Stroke-Cycle Marine Oils
For more information regarding oil certification, contact:
Scott Berry
Vice President of Engineering Standards
312.946.6254