Summary: The XM1 tank was developed with the objective of providing significant improvement in combat capabilities over the M60 series of main battle tanks. The Army's current estimate of the total program acquisition cost for 7,058 tanks is $10.9 billion, or $1.55 million a unit.
Although production of the Army's first increment of 110 XM1 tanks has begun, the tank's reliability is still to be proven. While recent testing indicated that modifications may have solved many of the faults disclosed in previous tests, serious doubts as to the tank's reliability and durability still remain. Problems have included incidences of engine power losses and even some total aborts, with the tank achieving only 145 mean miles between failures as of February, 1979 tests. During additional tests ending in October 1979, the tank was achieving 299 mean miles between failures, but the tests were neither as comprehensive nor as rigorous as the previous operational and development ones, the scores of which were either discarded or refined in the Army's latest evaluation. Because of the uncertainty of the tank's performance with its present turbine engine, members of the Congress have suggested on several occasions that the Army develop a backup diesel engine. The Army, however, has shown no enthusiasm for pursing this alternative, maintaining that the turbine has proven its reliability. The tank's improved performance should be tempered with the realization that the corrective modifications made to it in the past year are still to be tested in a combat environment. The tank's potential performance on the battlefield cannot be judged until the XM1 has demonstrated its reliability and maintainability in the next phase of operational and development testing.
