A fixed, Online Main engine performance monitoring system is essential for managing the fuel economy, Operating / Spares cost reduction and also to contribute Energy efficiency targets. Available for MAN B&W MC type engines, ME type engines and also for Wartsila RT Flex engines. A complete spare parts kit, consisting of shaft encoder ring, optical encoders, control panel, monitoring station and cabling shall be supplied to the ship for installation. System can be integrated with MAN MOP Operator panels and Engine control units (ECU) of ME type engine controllers. Generates Real time visual / graphical and printable versions of Main engine performance data for the user.