Sherman inflation
Sherman inflation is a change in the estimate of the number of Sherman tanks it would theoretically take to kill one Tiger tank. At the time of World War II, and in the recent movie Fury a common perception was that it would take about three Shermans. Over time this number has been inflated, with Wehraboos estimating as high as ten or more Shermans.
To some extent it is a rather pointless thought exercise, because Sherman's primary role was to support infantry, and the 75 mm gun that most of them carried was excellent at doing so. It fired a high explosive shell that was good for anti-personnel uses as well as destroying anti-tank guns.
There were also variants of the Shermans, the Fireflies, that carried a high velocity gun. They could fight tank duels on more even terms with Tigers, but this rarely happened. The Allies preferred to integrate tanks into a larger cohesive strategy that included artillery and air power, and by the late war period were very adept at dealing with German armor.
In this context the mobility, durability, and fuel economy of the Shermans made it a very effective medium tank. This is confirmed later on as Shermans continued to perform well into the Korean War era.