Mercury - Active Trim Kit Dual Engine 3.4L V6, 4.6L V8, 150HP FourStroke & OptiMax 150-250HP 8M0111552. Overview. The Mercury Active Trim Kit (8M0111552) is designed for dual-engine installations using Mercury's 3.4L V6, 4.6L V8, 150 HP FourStroke, or OptiMax 150-250 HP outboards. This system automatically adjusts both engines' trim for better performance, smoother acceleration, and improved fuel efficiency - all without manual input.. By automatically optimizing trim based on engine RPM and boa