Virtually all marine engines are two-stroke, which necessitates a particular type of motor oil. In a two-stroke engine, the fuel and oil are mixed so that the system is lubricated as it is supplied with gas. There are myriad reasons why two-strokes are superior for use on the water, but they also have their drawbacks. Because the oil is mixed with the fuel, two-stroke engines tend to emit an excess of burnt oil.
For manufacturers, the goal is to produce oil that can be used in a smaller proportion to the amount of fuel, such as Evinrude xd100. This will help eliminate much of the emissions that are created by excess oil in the system. Of course, this reduction in the oil to fuel ration can’t come at the expense of lubrication and performance. In order to develop criteria so that owners can recognize premium oils that meet all of this criteria, the NMMA developed TC-W3 certification, which we will be examining the rest of the week.