The most widespread version of the Leopard 2 family, the 2A4 models included more substantial changes, including an automated fire and explosion suppression system, an all-digital fire control system able to handle new ammunition types, and improved turret with flat titanium/tungsten armour.
The Leopard 2s were manufactured in eight batches between 1985 and 1992. All the older models were also upgraded to 2A4 standard. Germany operated a total of 2,125 2A4s (695 new built and the rest modified older versions), while the Netherlands had an additional 445 tanks. The 2A4 was also license manufactured in Switzerland as the Panzer 87 "Leopard" or Pz 87. This version included Swiss-built 7.5 mm Mg 87 machine guns and communications equipment, and featured improved NBC protection system. Switzerland operated 380 Pz 87 tanks.
After the end of the Cold War, Germany and the Netherlands found themselves with large stocks of tanks, which they did not have any need for. These tanks were therefore successfully sold to NATO or friendly armies around the world. Austria (114), Canada (80), Chile (140), Denmark (51), Finland (124), Greece (183), Norway (52), Poland (128), Portugal (37), Singapore (96) Spain (108), Sweden (160), and Turkey (339) were among the buyers of the surplus tanks.
The Pz 87WE (WertErhaltung) is a Swiss modification and upgrade of the Pz 87. The modification significantly improves protection, through the addition of the Leopard 2A6M's mine protection kit, thicker armour on the front glacis, and the turret is equipped with a Swiss-developed armour package that use titanium alloy. The turret roof armour is improved, and the smoke grenade launchers have also been redesigned. Further improvements enhance survivability and combat capability, such as a turret electric drive similar to the Leopard 2A5, a driver rear view camera, a independent weapons station for the loader, and enhanced command and control systems. The fire control system is also upgraded, using the Carl Zeiss Optronics GmbH PERI-R17A2 fire control system. A remote weapons station containing a fully stabilized Mg 64 0.50 calibre machine gun is also fitted to the tank.
The Pz 87-140 is an experimental variant of the Swiss Pz 87 with a 140 mm gun and an additional armor later used on the newer production variants.
The Leopard 2A4CHL is the upgraded Chilean version of the Leopard 2A4 ordered by Chile in 2007. Upgrades include new electronics, sighting and information systems meant to elevate the Leopard 2A4's networking capability to be equal to that of the Leopard 2A6, a new suspension system and the upgrading of the tanks main gun to the L55 smoothbore cannon used on the Leopard 2A6. Other upgrades are remote weapon stations over the gunner and commander hatches fitted with the MG3 and HK GMG. The Leopard 2A4CHL also has improved roof and side turret armour and can be uplinked with Chile's battlefield control network.