Mercruisers are inboard marine engines that are produced by Mercury Marine. Mercruisers were first introduced at the 1961 Chicago Boat Show and were the first inboard marine engines that offered over 100 horsepower. The 3.0 liter Mercruiser MPI is an inboard engine capable of producing 135 horsepower.
The Mercruiser 3.0 MPI has a four-stroke, four-cylinder engine. This engine’s cylinder bore has a diameter of 4 inches and the a stroke piston length of 3.6 inches. The compression ratio of this engine is 9.3 to 1. This engine is thermostatically cooled but also uses raw water at times.