Like all Soviet-legacy tanks, the T-72's design has traded off interior space in return for a very small silhouette and efficient use of armour, to the point of replacing the fourth crewman with a mechanical loader. The basic T-72 design has extremely small periscope viewports, even by the constrained standards of battle tanks and the driver's field of vision is significantly reduced when his hatch is closed. The steering system is a traditional dual-tiller layout instead of the easier-to-use steering wheel or steering yoke common in modern Western tanks. This set-up requires the near-constant use of both hands, which complicates employment of the seven speed manual transmission .
By the late 1970s, Indian Army HQ had decided to acquire new-generation replacements for its UK-origin fleet of Royal Ordnance Factories -built Centurion and Vijayanta MBTs, which are based on the licensed production of the Vickers MBT , and consequently, paper evaluations concerning the firepower and mobility characteristics of the two principal contenders being offered for full in-country production— AMX-40 developed by GIAT Industries of France , and the Chieftain 800 (which later evolved into the Challenger 1 from Royal Ordnance Factories (then owned by British Aerospace PLC)—were conducted by the Indian Army. Between these two contenders, the Army had by early 1980 zeroed in on the 43-tonne AMX-40 MBT, which was still on the drawing boards and was meant to be powered by a 1,100 hp Poyaud V12X 12-cylinder diesel engine coupled with a LSG-3000 automatic power shift transmission built by RENK Aktiengesellschaft of Germany (offering a power-to-weight ratio of hp/tonne, and armed with a 120 mm smoothbore cannon. However, AMX-40 has only marginal protection by the standards of 1980's. After coming back to power, the Indian Prime Minister Indira Gandhi requested additional evaluation, including MBTs from the USSR, following which the Soviet Union's Ministry of Foreign Economic Relations (which after 1991 morphed into Oboronexport, then Rosoboronservice and ultimately Rosoboronexport State Corp) made a formal offer to India's Ministry of Defence (MoD) for supplying the 37-tonne T-72M Ob'yekt 172M-E4 MBT off-the-shelf, and according an approval for licensed-production of the -tonne T-72M-1982 Ob'yekt 172M-E6 to the MoD-owned Heavy Vehicles Factory ( HVF ) in Avadi. By early 1981, two T-72 Ms—powered by a 780 hp diesel engine, armed with 125 mm 2A46M smoothbore gun and offering a power-to-weight ratio of 20 hp/tonne, were subjected to an exhaustive series of in-country firepower and mobility trials by the Army. After review of trial results, T-72M and T-72-1982 (powered by a Model V-84MS four-stroke 12-cylinder multi-fuel engine developing 840 hp and offering a power-to-weight ratio of hp/tone) were selected as Army’s future MBTs, and a procurement contract for 2,418 T-72s was subsequently inked.