K3

The K3 Tank is a next-generation main battle tank prototype being developed by Hyundai Rotem and South Korea's Agency for Defense Development to succeed the K2 Black Panther. [1]

Key Features

Propulsion: Designed to run on a hydrogen fuel-cell hybrid system for near-silent movement and low thermal signatures, with early variants using a dual diesel-hydrogen setup. [1, 2]
Armament: Features an unmanned, autoloaded 130 mm smoothbore main gun alongside a 30 mm secondary cannon. [1, 2]
Stealth & Armor: Incorporates radar-absorbent composite stealth armor that reduces its profile, often compared visually to the B-21 Raider. [1, 2]
Crew & Tech: Houses 2 to 3 crew members in a protected front hull capsule, utilizing artificial intelligence for targeting and drone deployment capabilities. [1, 2]
Timeline: Mass production is slated for around 2040. [1]

Most users on Reddit agree that the hydrogen hybrid choice provides major thermal stealth benefits by exhausting cooler water vapor instead of hot diesel fumes. [1]