The National Marine Manufacturers Association (NMMA) is now showing online it's 2018 lists of approved, or certified, TC-W3®, FC-W®, and Catalyst Compatible FC-W® engine oils. TC-W3® oils are recommended for use by two cycle engine manufacturers. FC-W® lubricants are required in today's high performance four-stroke engines. FC-W Catalyst Compatible® lubricants meet the catalyst-friendly four-stroke cycle marine engine oil specification that focuses on limiting catalyst poisoning.
NMMA licenses those two cycle lubricants that meet the stringent performance tests conducted by sanctioned laboratories approved by NMMA to conduct the tests. The tests include varied bench tests for fluidity, lubricity, viscosity, etc., plus the oil must meet minimum ring sticking and carbon build up on pistons in engine tests. The chemical make up of the TC-W3® oils vary due to the various additive packages involved with each oil brand. Accordingly, it's a performance based qualifications program. The testing process is comprehensive and expensive.
In previous discussions with Tom Marhevko, NMMA VP of Engineering Standards, Marhevko told OEM/Lube News "The oil registration program is on a calendar year so every year we archive the previous year list and start all over again. We continually add brands as they register. The renewals go out on December and most of the brands are renewed by April but stragglers come in throughout the summer and so the list is always being updated".
To view the complete 2018 TC-W3® list, visit http://www.nmma.org/certification/oil/tc-w3
To view the complete 2018 FC-W® list, visit http://www.nmma.org/certification/oil/fc-w
To view the complete 2018 Catalyst Compatible FC-W® list, visit
Please note: The pdf link to the 2017 lists are still shown on these NMMA pages. Please go toward the bottom of the page to view the 2018 lists.