Throughout World War 2 (1939-1945), the classic American M4 Sherman Medium Tank was subject to many tests and programs to help the series maintain a viable presence on the battlefield - particularly against the latest generation of German tanks. This eventually led to the Sherman being produced across several "generations" over its service life. First generation Shermans carried over several deficiencies from the M3 Grant Medium Tank line - from which it was largely based on - and this included its narrow track links as well as its Vertical Volute Spring Suspension (VVSS) system which gave poor ground performance.
Even as the war raged, work was actively being done on improving the Sherman's qualities and this resulted in the finalization of the "Horizontal Volute Suspension System" (HVSS) coupled to wider track links. While the addition made for a heavier and wider tank product, it improved the vehicle's operating ground pressure. The HVSS was applied to the M4A3 production model and gave rise to the M4A3E8 / M4A3(76)W HVSS designations - nicknamed "Easy Eight". The new vehicles were also completed with a larger-caliber 76mm High-Velocity main gun, featured welded hulls (as opposed to cast) and were powered by Ford GAA V8 gasoline engines. The revised qualities improved firepower (putting the main armament closer to the capabilities of the German 75mm guns), armor protection and performance over the earlier Sherman models.
Production forms were available as soon as August 1944 and the variant saw introduction during December of that year, seeing combat service during the Battle of the Bulge and beyond. However, despite the changes, this did not permanently solve ongoing issues with the medium tank when facing off against its German counterparts. The Sherman "Jumbo" (detailed elsewhere on this site) did more to address the lacking qualities - it saw a considerable increase in armor protection and carried a heavier gun. Beyond its given role as a Medium Tank, the Jumbo (M4A3E2) was also categorized as an "assault tank".
Production of Easy Eights totaled 2,617 examples during August 1944. These were completed by the Detroit Tank Arsenal as well as the Fisher Tank Arsenal.