M46 Patton The M46 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 . On 30 July 1948 , the M46 was named the Patton , in honor of General George S . Patton Jr . It was not widely used by U . S . Cold War allies , being exported only to Belgium , and only in small numbers to train crews on the upcoming M47 . The M46 tank was designed to replace the M26 Pershing and M4 Sherman . History . 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 . Work began in January 1948 on replacing the original power plant with the Continental AV1790 - 3 engine and Allison CD - 850 - 1 cross - drive transmission . The design was initially called M26E2 , but modifications continued to accumulate , and eventually the Bureau of Ordnance decided that the tank needed its own unique designation . When the rebuild began in November , 1949 , the upgraded M26 received not only a new power plant and a main gun with bore evacuator , but a new designation along with a name - simply M46 . In total , 1 , 160 M26s were rebuilt : 800 to the M46 standard , 360 to the M46A1 . Combat service . The only US combat use of the M46 was in the Korean War . On 8 August 1950 the first M46 Patton tanks belonging to the 6th Tank Battalion landed in South Korea . The tank proved superior to the much lighter North Korean T - 34 - 85 , which were encountered in relatively small numbers . By the end of 1950 , 200 M46 Pattons had been fielded , forming about 15 % of US tank strength in Korea ; the balance of 1 , 326 tanks shipped to Korea during 1950 included 679 M4A3 Shermans , 309 M26 Pershings , and 138 M24 Chaffee light tanks . Subsequent shipments of M46 and M46A1 Pattons allowed all remaining M26 Pershings to be withdrawn during 1951 , and most Sherman equipped units were also reequipped . Known M46 series operators include : 1st Marine Tank Battalion and regimental Antitank Platoons of the 1st Marine Division by 1952 , 72nd Tank Battalion of the 2nd Infantry Division by January 1952 , 64th Tank Battalion of the 3rd Infantry Division , 73rd Tank Battalion of the 7th Infantry Division by January 1951 , 6th Tank Battalion of the 24th Infantry Division , 140th Tank Battalion ( took over the tanks of the 6th Tank Battalion ) and regimental tank companies of the 40th Infantry Division ( CA ARNG ) by October 1951 , and the 245th Tank Battalion of the 45th Infantry Division ( OK ARNG ) by 1952 . Several other regimental tank companies gained M46 / M46A1s by the end of the war , including the 7th and 65th Infantry Regiments of the 3rd Infantry Division . In the 1950s , small numbers of M46s were leased , at no cost , to some European countries for training purposes , including Belgium , France and Italy , in preparation for the introduction of the M47 . US instruction teams used the vehicles to train European tank crews and maintenance personnel .