Al Khalid P1
The P1 sported the German-based MTU-396 diesel engine mated to an LSG-3000 automatic transmission while fielding a Chinese-made 125mm main gun, fire-control system and autoloader.
Al Khalid P2
The P2 had a Perkins Condor 1,200 horsepower diesel engine (used in the successful British Challenger MBT series), a French SESM ESM500 (ala the Le Clerc MBT) and western-based fire-control system.
Al Khalid P3 (was chosen as production version)
The P3 sported a Ukrainian 6TD-2 1,200 horsepower engine but essentially the P2 prototype.
Al Khalid I (Turret face ERA)

Al Khalid I (Hull + Turret face + sides ERA)

Al Khalid II (Prototype) mockup
Al Khalid P4 was not made because of embargoes
The P4 was given the NATO-standard 120mm main gun tied into a western-based fire-control system along with a German-based MTU-871/TCM AVDS-1790 diesel engine with LSG-3000 automatic transmission. The P4 was intended to become an export product for Pakistan to produce, operate and sell to other prospective global buyers.