The Abrams X is a proposed next generation MBT expected to be released around 2030. Although nothing is finalized yet, the AbramsX will reportedly weigh around 60 tons, or 10 tons less than the operational M1A2 Abrams, which packs an impressive 71 tons.
The Army is likely trying to rein in on the weight and bring the future tank on par with the first Abrams tank of the family, the M1 Abrams. Less weight means more speed and less fuel consumption, both important features in ground combat.
The AbramsX will also likely have a new hybrid electric diesel engine that would be more efficient than the fuel-hungry M1A2 Abrams. In addition, the Abrams X will likely have enhanced armor to protect against loitering munitions and suicide drones.
Another potential feature of the future main battle tank would be an unmanned turret, which would reduce the crew from four to three. Most Western tanks have a crew of four (commander, gunner, loader, driver).