The Wankel engine is a type of internal combustion engine that uses a rotary design instead of the traditional piston mechanism. It features a triangular rotor that moves in an oval-shaped chamber, creating three separate combustion chambers. This design allows for a smoother operation and fewer moving parts, which can lead to a lighter engine. Wankel engines are known for their compact size and high power-to-weight ratio, making them popular in certain applications like sports cars and motorcycles. Notably, the Mazda RX-7 and Mazda RX-8 are famous vehicles that utilized the Wankel engine, showcasing its unique performance characteristics.