Goha.ru info-source provides history and combat service of another upcoming tank - the M46 Patton, which will be introduced with v.0.6.5 patch.
M46 was a medium tank, designed in the United States, and was the first tank to be named after General George S. Patton, commander of the U.S. Third Army during World War II and one of the earliest American advocates for the use of tanks in battle. The tank itself was an improved M26 Pershing tank and one of the U.S Army's principal medium gun tanks of the early Cold War, with models in service from 1949 to the mid 1950s.
"After World War II, most US Army armored units were equipped with a mix of M4 Sherman and M26 Pershing tanks. Designed initially as a heavy tank, the M26 Pershing tank was reclassified as a medium tank postwar. The M26 was a significant improvement over the M4 Sherman in firepower and protection. Its mobility, however, was deemed unsatisfactory for a medium tank, as it used the same engine that powered the much lighter M4A3. Its underpowered engine was also plagued with an unreliable transmission."