Over the last five years, the U.S. Army has had to reform the way it takes care of its M-1 tanks and their components. Given that these tanks are now full of computers, as is the army in general, new maintenance and supply systems could be connected to the Internet. This made it possible to better monitor the status of armored vehicles, and improve maintenance and rebuilding of some components. In particular, the 1500 horsepower gas turbine engine of the M-1 has seen downtime reduced considerably, along with the cost of maintenance. The service life of rebuilt engines has doubled, to 1,400 hours. The gas turbine engines are, essentially, jet engines, and they took a beating in Iraq (with all the sand and airborne grit.) Maintaining jet engines is a tricky business, but the army was doing this for its helicopter fleet several decades before the M-1 came along. But all those computers and the Internet allowed for unprecedented precision and timeliness when it came to maintenance.
These upgrades were is the result of the impressive performance of the U.S. M-1 tank in Iraq. Not just during the 2003 invasion, but during the five years spent battling Islamic terrorists after that. This prompted the army to scrap plans to retire the M-1, and replace it with a radical new FCS (Future Combat System) design. None of the proposed FCS designs showed much potential, especially compared to how well the M-1 was doing.
This led to upgrades for the M1 tank. Now there's an M1A3 version of the M1 in the works. This would be a radical upgrade, compared to previous ones. It would even be possible to make the 62 ton M-1A2 a few tons lighter. This would involve a lightweight 120mm gun, which would allow for the installation of an autoloader, new fiber optic wiring, and new (and lighter) armor. A new engine and running gear would also save weight. The M-1A3 might get down to 55 tons, or less.
But the most important changes would be the new computers, communication, sensors and navigation gear intended for the unrealized FCS tank. The FCS vehicle was to use new heavy weapons, that fire guided projectiles to a range of 12 kilometers. These can also be mounted in the M-1A3.
There would be no new tanks built, just upgrades of existing ones. Nearly 9,000 M-1s were manufactured during the 1980s and 90s. The U.S. Army and Marines only use about 1,600 now, with foreign operators accounting for another 1,500. So there are plenty of older M-1s in storage, ready for upgrading. The M-1A3 could remain in service for another forty years or more.