Sierra TC-W3 2-Stroke Synthetic Marine Oil 18-9540-3 Sierra TC-W3 is a fully synthetic two cycle engine oil designed for marine applications. Designed to provide excellent engine protection with superior lubrication for all two-cycle oil injection systems. Whether you premix or have a state of the art advanced lubrication system, the TC-W is perfect for harsh marine environments. Exceeds JASO, ISO, API, NMMA for advanced gen 2 cycle lubricants. Features Direct replacement for BRP XD-100 2 Stroke