The Leopard 1 is an older design, first produced in 1965. It weighs 42 tons and is capable of reaching 65 kilometers per hour at top speed. The Leopard 1 has a 105-millimeter gun (the standard NATO tank gun in that time period) and carries 60 rounds for the gun. While adequate when it was built in the 1960s, the 105-millimeter gun is marginal against more modern tanks. More importantly, the armor (70 millimeters of steel at its thickest point) is very thin compared to todays major tanks, and was a little on the thin side compared to tanks that entered production at the same time and was likely to face off against, like the Russian T-62 (242 millimeters of steel at its thickest point).
The contenders to replace the Leopard 1 are better in both main armament (all have 120-millimeter guns), and in terms of armor (a blend of composites and steel). The Leopard 2 and the M1A2 Abrams use the same gun, while the British Challenger 2 uses a different 120-millimeter gun that has a longer range (during Desert Storm, a Challenger destroyed an Iraqi tank from roughly 5,000 meters away).
The German Leopard 2, a follow-on to the Leopard 1 used by Australia (and several other nations) weighs in at 55 tons, with a top speed of 72 kilometers per hour. The tank also carries 42 rounds for its 120-millimeter Rheinmetall smoothbore gun. It used to carry the L44 gun, but the Leopard 2A6 version carries the newer L55 gun. The armor is much improved over the Leopard 1 (700 millimeters against all metal "penetrator" anti-tank shells). It has the widest acceptance in the export market, being used by Switzerland, Austria, Denmark, Spain, the Netherlands, and Sweden.
The British Challenger 2 is the primary tank used by the United Kingdom. While it looks like the earlier Challenger, it is a new main battle tank for all intents and purposes. The L30 120-millimeter rifled gun gives the 62.5 ton tank a long reach. The tank holds fifty rounds for the L30, but can only reach 56 kilometers per hour. Despite having the best armor protection in NATO, the tank has not had wide acceptance in the export market. Only Oman has purchased this tank, while the Challenger 1 version has been passed on to Jordan.
The American M1A2 is the most modern version of the Abrams tank that was tested in Desert Storm and Operation Iraqi Freedom. The Abrams uses the same 120-millimeter smoothbore gun as the Leopard 2 (known as the M256), and while it weighs 63 tons, the heaviest of the three contenders, it is still quite fast (67.6 kilometers per hour at top speed). The Abrams has received some export orders from Egypt, Saudi Arabia, and Kuwait.
The competition was apparently between the Leopard 2 and the Abrams, with the Challenger 2 a distant third in the competition. The Leopard 2 was thought to have the advantage due to the use of its predecessor by the Australian military, but the Abrams has the advantage of being tested in two major wars, gaining a reputation for toughness (an M1A1 deflected an armor-piercing round fired by an Iraqi T-72 at 400 meters during Desert Storm in an incident recounted in From Shield to Storm).
Australias close work with the United States in the war on terror is a second factor in favor of the Abrams. The Australian Ministry of Defense has stated that no final decision has been made, and that final submissions are still being assembled. Harold C. Hutchison
The Australian Ministry of Defense appears to have selected the M1A2 Abrams to replace Australias old Leopard 1 main battle tanks, if recent comments by an American general in Iraq are correct. The Abrams had been competing for the order, consisting of two battalions (108 tanks), with the German Leopard 2 and the British Challenger 2.