Historically, gasoline-powered inboard and inboard/outboard (sterndrive) boats have been equipped with four-stroke cycle engines. With growing interest and legislation in reducing marine engine emissions, these four-stroke cycle engines are now appearing with exhaust after-treatment. In recognition of emerging four-stroke cycle engines with catalysts in the marine market and their unique lubrication demands, the NMMA initiated the development of a new four-stroke cycle engine oil specification, “NMMA FC-W Catalyst Compatible®.”

The need to protect the catalysts adds another dimension to the lubrication demands of marine engines whose duty cycles have always discriminated them from over-the-road light and heavy duty automotive engines. High loads, high speeds, and exposure to high levels of humidity and salt water are just a few of the unique characteristics found in marine engines.

This new catalyst-compatible standard draws heavily on the experience and success of the earlier NMMA FC-W® standard, which was developed to meet the needs of large and technically advanced four-stroke cycle marine engines. These include four-stroke cycle outboard engines, which are now taking the place of some conventional two-stroke cycle outboard engines. As a result, the new catalyst-compatible standard can provide the performance required for engines that would otherwise call for NMMA FC-W® lubricants.

This new catalyst-compatible specification follows the longstanding and successful tradition of BIA TC-W, NMMA TC-WII®, NMMA TC-W3®, and NMMA FC-W® programs to assist boaters and manufacturers in identifying the proper engine oils which have been specially formulated to withstand the rigors of use in marine engines. The NMMA FC-W Catalyst Compatible® specification is intended to support the industry in providing long term durability, power and overall consumer satisfaction with marine engines utilizing catalyst after-treatment.
 

2025 FC-W (CAT)® Marine Oils

Number Name Company
FC-01750T Pro Star 4 Stroke 25W40 Outboard Oil KINPAK, INC.
FC-01810T Pro Star 4 Stroke 10W40 Outboard Oil KINPAK, INC.
FC-01820T Pro Star 4 Stroke 10W30 Outboard Oil KINPAK, INC.
FC-105159D Synergy Synthetic Marine ExP 10W-40 Northland Products Company
FC-11298X Ravenol Outboardoel 4T SAE 10W-40 Ravensberger Schmierstoffvertrieb GmbH
FC-118905Z Starbrite Star Tron 25W40 KINPAK, INC.
FC-162395Z Starbrite Star Tron 10W30 KINPAK, INC.
FC-251582D Synergy Synthetic Marine ExP 25W-40 Northland Products Company
FC-350367Z LIQUI MOLY Marine 4T Motor Oil 10W-30 Liqui Moly GmbH
FC-427822C Starbrite Star Tron 10W40 KINPAK, INC.
FC-43514X Ravenol Marine Oil Petrol SAE 25W-40 Ravensberger Schmierstoffvertrieb GmbH
FC-43517X Ravenol Outboardoel 4T SAE 25W-40 Ravensberger Schmierstoffvertrieb GmbH
FC-481526D Synergy Synthetic Marine ExP 10W-30 Northland Products Company
FC-51534X Ravenol Outboardoel 4T SAE 10W-30 Ravensberger Schmierstoffvertrieb GmbH
FC-738288Z LIQUI MOLY Marine 4T Motor Oil 25W-40 Liqui Moly GmbH
FC-783006Z LIQUI MOLY Marine 4T Motor Oil 25W-50 Liqui Moly GmbH

For more information regarding oil certification, contact:

Scott Berry
Vice President of Engineering Standards
312.946.6254