A rotary engine is a type of internal combustion engine that uses a rotating design to convert pressure into rotational motion. Unlike traditional piston engines, which use multiple cylinders and pistons, rotary engines have a triangular rotor that moves in an oval chamber. This design allows for fewer moving parts and a more compact engine size. Rotary engines are known for their smooth operation and high power-to-weight ratio. They are commonly found in some Mazda vehicles, such as the Mazda RX-7 and Mazda RX-8. Despite their advantages, rotary engines can be less fuel-efficient and produce more emissions compared to conventional engines.