Three different engines are used by the NMMA to test the oils and determine if they meet TC-W3 certification standards. First, the outboard motor oil is tested on a BRP 40 hp engine and a Johnson 70 hp. They also run two consecutive tests using a Mercury 15 hp motor and two separate lubricity tests. This variety of testing ensures that the oil’s performance is uniform in all two-stroke engines.
During the tests, the engines run for 100 hours each. Every ten hours during the test, the testers stop the engines and the oil is inspected. The testing process remains constant regardless of the manufacturer and chemical makeup of the oil. Many boat manufacturers specify TC-W3 certified oils for their engines, so receiving TC-W3 certification can be a boon for an oil manufacturer.