Mercury - Active Trim Mechanical Kit MerCruiser Single Engine 8M0111550. Overview. The Mercury Active Trim Mechanical MerCruiser Single Engine Kit (8M0111550) is built specifically for single-engine 4.5L and 6.2L MerCruiser sterndrive installations. This system automatically adjusts your engine trim for smoother acceleration, better fuel economy, and consistent handling - no manual trim inputs needed.. Active Trim monitors engine RPM, boat speed, and running attitude to keep your boat performing