For all those people who do not understand the Sherman Tank, please read:
It was said that the U.S. had matched the superior quality of the German tanks only by superior quantities of American tanks. And this was largely true. The Sherman did not fare well in tank-to-tank slugging matches with their giant German counterparts-shells often harmlessly bounced off the thick German armor. Interestingly enough, before entering the war, the U.S. did develop some extremely heavy tanks, but later switched to lighter tanks for the following reasons.
The U.S. tanks had to be transported by ship from Detroit, across a vast ocean to land amphibiously on enemy shores. This reality placed great limitations on the size and weight of the tanks. Especially with the frequent U-boat sinkings, the number of U.S. ships was dropping, and the bigger the tank, the fewer a ship could carry.
Another factor that faced the U.S. was moving their armor over bridgeless streams. The U.S. Air Force was targeting enemy bridges as a means of disrupting enemy supply lines, etc. Once these bridges were destroyed, U.S. tanks would have to cross the streams on temporary bridges. Heavy tanks could not have crossed, but the lightweight and nimble Shermans could.
Also, while the Tiger and Panther were made bigger and more powerful than the Sherman was, they were comparatively slow and ponderous. The German tanks were often used as pill-boxes, forced to become immobile and fire at oncoming armor. On the other hand, the Sherman was designed for deep thrusts into the enemy's rear, where it would destroy supply installations and communications. This demanded great speed and minimal fuel consumption.
But perhaps the greatest reason behind the success of the Sherman was its reliability-maximum performance and minimum care and replacement. General George Patten recognized this when he declared, "In mechanical endurance and ease of maintenance our tanks are infinitely superior to any other". This factor played out on the battlefield, allowing the Sherman to out-run, out-maneuver, and ultimately out-fight the Tiger and Panther.
With about 50,000 produced in all variations, the Sherman was the most widely produced tank during the war. The five major variants of the M4 to the M4A4 were designated by the hull and engine used. Although powerful and proven, its high center propeller shaft gave the hull a tall profile. Suspension was a rugged and simple design, known as VVSS (Vertical Volute Spring Suspension), with three units (or bogies) on each side, and each with two road wheels. The transmission was 5-speed forward plus reverse. Early production M4's had a 3-piece front transmission cover, and a cast one-piece steel turret mounting a 75mm main gun. For added protection, oblique armor plates were added to the turret, hull sides and just in front of the forward hull hatches. Production of the M4 began in July 1942, five months later than the cast hulled M4A1. One of the most powerful variants of the M4 Sherman was the 105mm howitzer equipped version, which provided valuable fire support for the U.S. Army and Marines as well as extensive use in anti-tank operations.