As a result, the modification of the Leopard 2 prototypes in order to meet the US Army requirements was investigated. Following a number of further talks, a memorandum of understanding (MOU) was signed on 11 December 1974 between the Federal Republic of Germany and the United States of America, which declared that a modified version of the Leopard 2 should be trialled by the USA against their XM1 prototypes,after the Americans had bought and investigated prototype PT07 in 1973. The MOU obligated the Federal Republic of Germany to send a complete prototype, a hull, a vehicle for ballistic tests and a number of special ballistic parts to the USA, where they would be put through US testing procedures for no additional costs.
The Leopard 2 is often compared to its near contemporary, the M1 Abrams: in truth the two designs share broadly similar characteristics, including a scale-tipping weight of well over sixty tons of advanced composite armor, 1,500 horsepower engines allowing speeds over forty miles per hour and, for certain models, the same forty-four-caliber 120-millimeter main gun produced by Rheinmetall.
Credit to : U.S. Military Technology