TC-W3 2 Stroke Oil

Most current two-stroke outboard oils carry a TC-W3 rating. This rating is an industry certification, administered by the National Marine Manufacturers Association (NMMA), the people who operate the majority of boat shows around the country. The TC-W3 rating replaced the earlier TC-WII rating sometime in the early ’90s, but the ratings originated in the 1980s as lead was phased out of our gasolines.

The industry came up with a testing procedure to certify a basic and uniform level of lubrication and engine protection, and TC-W3 is the latest link in that evolution. The TC-W3 oils were specifically targeted toward piston-ring cleanliness, and the lubricity was substantially improved over what TC-WII oils had to offer.

Oils tested for certification by the NMMA must pass a series of grueling tests to receive the TC-W3 certification. The NMMA testing procedures are done using four engines: a 40-hp and a 70-hp Evinrude, a 15-hp Mercury and a 50-hp Yamaha. The oils are put through specific tests in each engine. For example, the 40-hp outboard is used to test ring stickage, while the 70-hp outboard is used to test for piston deposits. Each engine is examined for a different aspect of the oil’s performance.

If a 2 stroke marine oil meets or exceeds a certain set of criteria in each of the tests, it gets a TC-W3 rating, and the containers in which the oil is subsequently sold can carry a TC-W3 emblem signifying that the marine oil passed the tests.