The Prince G-series engine was the company's only straight-four and straight-six engines which began production in 1955. A number of variations were made, with both OHV and OHC heads. A diesel four-cylinder with was also built, called the D-6. The G series was used in the Skyline, the Laurel, and the Gloria from the 1950s to the early 1970s. Note that, prior to its merger with Prince, Nissan also made a G series of engines. These are unrelated engines and are documented at the Nissan G engine page. The source of the listed information is the corresponding article at Japanese Wikipedia. Flat-2 In 1956, Prince developed a flat-2 engine, the FG2D, for their DPSK (later CPSK) concept car. It displaced 601 cc and produced . The engine suffered excessive vibration and noise issues and was replaced with the FG4C engine. Flat-4 Prince developed the FG4C, a flat-four displacing 599 cc and producing , as a replacement for the FG2D. The FG4C was used in the 1957 CPSK concept. Straight-4 FG4A-10 diameter X stroke: , OHV Maximum output (gross) @ 4000 rpm Maximum torque (gross) @ 2000 rpm 1952-1955 Prince Sedan AISH 1952-1954 Prince Truck AFTF FG4A-20 diameter X stroke: , OHV Maximum output (gross) @ 4000 rpm Maximum torque (gross) @ 2000 rpm 1955-1956 Prince AIPC-1 1955-1956 Prince AIVE-1 1955-1957 Prince Sedan AISH 1955-1956 Prince Truck AFTF 1955-1956 Prince Truck AKTG 1956 Prince BNSJ concept (increased to 1.9L) FG4A-30 diameter X stroke: , OHV Maximum output (gross) @ 4000 rpm Maximum torque (gross) @ 2000 rpm Renamed GA-30 in 1958 Applications: 1957 Prince AIPC-2 1957 Prince AIVE-2 1957 Prince Sedan AISH-6 1957 Prince Truck AFTF-8 1957 Prince Miler AOTH-1 1957 Prince Miler AOVH-1 1957 Prince ALPE-1 1957 Prince ALVG-1 1957 Prince AKTG-4 GA-30 diameter X stroke: , OHV Maximum output (gross) @ 4400 rpm Maximum torque (gross) @ 3200 rpm 1957 Prince Skyline ALSI-1 1957-1961 Prince Skyline ALSI-2 1957-1958 Prince Truck ALPE 1958-1959 Prince Miler ARTH-1 (New Miler) 1958-1960 Prince Truck AQTI-1 GA-4 diameter X stroke: , OHV Maximum output (gross) @ 4000 rpm Maximum torque (gross) @ 2000 rpm 1959 improvement on the GA-30; also known as FG4A-40 Mechanical similarities with engine used in Subaru 1500 Applications: 1957-1959 Prince Skyway ALVG 1959-1963 Prince Miler ARTH-2 1958 Prince Miler Van ARVH-1 1958-1961 Prince Skyline ALSI-2 1959-1961 Prince Skyway 1959 Prince ALPE-2 1959 Prince ALVG-2 1960 Prince Truck AQTI-2 1962-1964 Prince