Editing M4 Sherman (section)

===M4A1===
In September 1942 the British developed some potential improvements and tested the tanks.<ref name="Archive Canadian Military Headquarters 1947">Archive Canadian Military Headquarters, London (1939–1947) RG 24 C 2</ref>{{sfn|Hunnicutt|2015|p={{page needed|date=September 2021}}}}

After {{convert|805| km|abbr=on}} the springs of the left front bogie broke, considered typical for this type of suspension. Oil accumulated on the floor of the engine compartment during driving. The engine periodically stalled under high load due to interrupted fuel supply. It was found that the engine had been built and installed incorrectly. Upon disassembly carbon deposits were found on the working surfaces of the cylinders; they were very worn out after only 65 hours of operation or {{convert|702| mile|abbr=on}} run. In the absence of a replacement by 10 October, the engine was put back in the tank; the revised fuel system was supposed to improve the stalling engine.

In November 1943, several M4A1 Shermans were tested at the American proving ground to test British innovations. On one of them, 37 experimental changes were made, on the second – 47, on the third – 53. In total, 60 changes were developed and implemented for the Shermans, most of which were considered successful after a 600-mile run and firing.<ref name="Archive Canadian Military Headquarters 1947"/>