The T‑80 and its variants are in service in Belarus, Cyprus, Egypt, Kazakhstan,[15] Pakistan, Russia, South Korea, Ukraine and Uzbekistan.

The turbine engine allowed the tank to reach a maximum speed of 57.3 km/h (35.6 mph), however with only 1,950 liters of fuel on board, their range was limited to only 300 km (190 mi).

During the trials it became clear that the increased weight and dynamic characteristics required a complete redesign of the vehicle's suspension.

As such, the T-72 was intended to be a tank mass-produced to equip the bulk of the Soviet motor rifle units, and for sale to export partners and Eastern-bloc satellite states.

(Morozov's subsequent parallel development of the T-80UD replaced the gas turbine with a commercial turbo-diesel, to decrease fuel use and maintenance needs.)

The T-80U main battle tank (1985, "U" for uluchsheniye, meaning "improvement") was designed by SKB-2 in Leningrad (hull) and the Morozov Bureau (turret and armament).

This gas turbine can use jet fuels, diesel, and low-octane gasoline, and has good dynamic stability, service life, and reliability.

The T-80U's 1A46 fire control system includes a laser range finder, a ballistics computer, and a more advanced 1G46 gunner's main sights, which greatly increases the T-80Us firepower over previous models.

These new systems, together with the 125 mm D-81TM "Rapira-3" smooth bore gun, ensure that the T-80U can hit targets at a range of up to 5 kilometers (ATGMs and HV/APFSDS).

An experienced crew at the international exhibition was able to successfully strike 52 targets without a miss at a distance of 5 km using guided rockets.

T-90s, which were not deployed to Chechnya, were spared media criticism despite the similarly poor performance of the T-72 (the T-90's not-so-different ancestor) in the same conflict.

It is powered by the 1,000 hp 6TD-6-cylinder opposed-piston[28] multi-fuel two-stroke turbo-piston diesel engine, ensuring high fuel efficiency and a long cruising range.

The engine support systems make it possible to operate the tank at ambient temperatures of up to 55 °C and ford water obstacles 1.8 m in depth.

The T-80UD shares most of the T-80U's improvements, but can be distinguished from it by a different engine deck and distinctive smoke-mortar array and turret stowage boxes.

[32] In August 1991, communists and allied military commanders tried to overthrow Mikhail Gorbachev and regain control over the unstable Soviet Union.

During the 1993 Russian constitutional crisis, Boris Yeltsin ordered the use of tanks against the Supreme Soviet and the Congress of People's Deputies opposing him.

This first real combat experience for T-80 was unsuccessful, as the tanks were used to capture cities, a task for which they were not very well suited, in particular due to the low depression and elevation of the 2A46-M1 gun on all Russian MBTs.

[39] The inexperienced crews had little knowledge of the layout of the city, while the tanks were attacked by rocket-propelled grenade teams hidden in cellars and on top of high buildings.

Russia originally agreed to repay the loan by 1999, but the Russian government requested a delay due to its own circumstances, which led the expected accumulated sum of principal and interest to near $3 billion.

Therefore, South Korea launched the Project Brown Bear to collect the debt by purchasing the Russian weapons at a 50% discounted price.

After the first batch of 15 vehicles had been shipped in February 1997, Russia protested that it held the rights to the tank and that Ukraine could not export it.

Under the guise of keeping good relations with India, one of its most important military customers, Russia withheld 2A46-2 125 mm smoothbore guns, cast turrets and other technology, which forced Ukraine to make its tank industry independent.

New tanks gave the Cypriot National Guard the edge in a possible confrontation with the Turkish Army in Northern Cyprus.

Suspension reverts from pneumatic to torsion bar, with six forged steel-aluminium rubber-tyred road wheels on each side, with the tracks driven by rear sprockets.

[64] The turret houses the same 125 mm 2A46 smoothbore gun as the T-72, which can fire regular ordnance and anti-tank guided missiles.

The propellant charge is held inside a semi-combustible cartridge case made of a highly flammable material, which is consumed in the breech during firing, except for a small metal baseplate.

[citation needed] A disadvantage highlighted during combat in Chechnya was the vulnerability of the T-80BV to catastrophic explosion[65] thought to be caused by the vulnerability of stored semi-combustible propellant charges and missiles when contacted by the molten metal jet from the penetration of a HEAT warhead, causing the entire ammunition load to explode.

During the Chechen war 1994, the Russians were able to reduce their losses by having their tanks carry fewer rounds so that all the ammunition and propellant was stored in the autoloaders[68] This vulnerability may be addressed in later models.

When modern Western tank designs changed from non-combustible propellant cartridges to semi-combustible, they tended to separate ammunition stowage from the crew compartment with armoured blast doors, and provided "blow-out" panels to redirect the force and fire of exploding ammunition away from the crew compartment.

[65] This section lists the main models of the T-80, built in the Soviet Union, Russia and Ukraine, with the dates they entered service.