What name is commonly given to Leonardo da Vinci’s four-wheeled vehicle powered by a wound spring?

Leonardo da Vinci’s four-wheeled vehicle powered by a wound spring is commonly called the self-propelled cart.

Leonardo designed the cart around 1478–1480. Unlike a modern automobile, it had no engine or fuel system. Two large leaf springs stored mechanical energy, and that energy was released through gears to turn the wheels. A steering system also allowed the cart to follow a predetermined route.

The machine was probably intended as a theatrical prop rather than practical transport. One proposed use was to make it move across a stage during court festivities. Because the design could be set to travel automatically, it is sometimes described as an early robot or programmable machine.

The surviving drawings do not show every construction detail, so modern reconstructions have involved interpretation. In 2006, a team built a working model based on Leonardo’s drawings. The vehicle is often misleadingly called Leonardo’s car, but “self-propelled cart” better describes its spring-driven mechanism and limited purpose.