 The M4A3 used the liquid-cooled Ford GAA V8 gasoline engine, and the M4A4 used the liquid cooled 30 cylinder Chrysler A57 multibank gasoline engine.There were also two diesel engined variants.The M4A2 was powered by a pair of liquid cooled GMC 6–71 two-stroke inline engines, that produced a total of , while the M4A6 used an RD-1820 (a redesigned Caterpillar D-200A air cooled radial diesel engine, adapted from Wright Aeronautical's "Cyclone 9" nine cylinder radial aircraft engine.)