All Mark IVs were equipped with the -4V Ford 385 series 16-valve V8 ("4V" is in reference to the 4-venturi Autolite carburetor). Rated at 365 hp (gross)in the Mark III, the 460 was carried over to the Mark IV. For 1972, rated output underwent a numeric decrease to 212 hp. In order to comply with changing EPA emissions regulations, Ford was required to decrease the compression ratio of the engine. The same year, American auto manufacturers adopted SAE net horsepower as its standard of measuring engine output, to better reflect real-world engine performance (as installed in vehicles). All examples of the Mark IV were equipped with a Ford C6 three-speed automatic transmission.