Why doesn't the world still go around in da Vinci's spring powered car?

Question

Why doesn't the world still go around in da Vinci's spring powered car?

Answer 1

Because you'd have to wind the spring up somehow. A spring large enough to drive a modern car would be way to big to charge by hand, you'd have to use an internal combustion (petrol or diesel) engine.

For a while, there were busses in London that ran off a large flywheel which was charged up as they left depot.