Finally, the M4A4. It was powered by 5 6-cylinder engines bolted together, which necessitated extending the hull. The M4A4 therefore had a noticably longer profile than the other types. This type was not used operationally as a gun tank by the US Army (which regarded the power plant as unsatisfactory), but it was used for training in the US. It was widely used by the Allies - principally the British (as the Sherman V), but also the Canadians, Free French and Free Poles in NW Europe and Italy. A small number were also used by the British and the Chinese 1st Provisional Tank Group in Burma.
Distinguishing features: elongated hull with additional space between bogies, radiator bulge behind turret, sloping rear hull without visible exhaust, 'low bustle' turret.
Early production: M4 bogies, bolted transmission housing (all M4A4s had the bolted transmission housing), direct vision ports and narrow M34 mantlet.
Mid production: M4 bogies, bolted transmission housing, periscopes instead of direct vision ports, narrow M34 mantlet (transitioning to wider M34A1 mantlet during production). Many were rebuilt to late production standard in 1944.
Late production: M4 bogies, bolted transmission housing, periscopes instead of direct vision ports, wide M34A1 mantlet, appliqué armour on the hull sides, glacis and (depending on when the turret was produced) on the right turret cheek, sand shields and gun travel lock.