The design of marine gasoline engines, both two- and four-stroke, have advanced to the point where higher output engines place severe demands on engine lubricants. Likewise, concern over pollution has increased fuel/oil ratios, which, in turn, increase lubricant requirements. To help boaters recognize lubricants that will give the engine life designed-in by marine engine manufacturers, the National Marine Manufacturers Association (NMMA) has developed a program for the certification of these premium quality lubricants.
The entire NMMA Marine Oil Certification program consists two parts, a certification program for oil additive packages and a registration program of oil brands using certified oils.
The registration for marine oil brands is conducted on an annual basis. All marine oils registered with NMMA are listed on this website. The TC-W3® symbol signifies a marine oil designed for two-stroke marine engines, the FC-W® symbol signifies a marine oil designed for four-stroke marine engines and the FC-W(CAT)® symbol signifies a marine oil designed to be compatible with four-stroke marine engines that have an exhaust after-treatment catalyst.