As the M1 Abrams entered service and work began on the M1E1 model with a 120 mm gun, there was a need to synergize the original M1 Abrams' specification with new features implemented into the M1E1. This became the Improved Performance project and saw the turret improvements to the M1E1 implemented into the M1, which improved the overall turret armour. There were other miscellaneous changes for crew comfort such as a rear turret bustle rack for stowages and a cut down rear side skirt for better access to the sprocket wheel. The overall tank designation became known as the IPM1, and 894 units were produced between 1984 and 1986. The IPM1 did not see combat in its configuration, though it was involved in the 1987 Canadian Army Trophy competition and was deployed in Operation Desert Shield before being replaced by the M1A1 tank.
Introduced in Update 1.81 "The Valkyries", IPM1 features improved composite protection in the turret cheeks. This enables a more aggressive gameplay as the turret could withstand more kinetic and shaped-charge munitions than the original version. It can also be equipped with the M900 APFSDS round, which can more easily penetrate enemy tank armour. That said, the IPM1's hull armour did not see any improvement and the large turret ring area remains a significant weakpoint, so players should keep these frontal weak points in mind even when facing weaker opponents.