Why does the Audi A2 have such a high fuel efficiency compared to other vehicles?

I have read that the Audi A2 has a fuel efficiency of around 64 MPG, which seems significantly higher than other vehicles. Can you explain the technology behind this and how it achieves such a high efficiency?

The Audi A2's high fuel efficiency is achieved through its lightweight construction and aerodynamic design. Its body is made of aluminum, which reduces weight while maintaining structural integrity, and its smooth curves help reduce drag while driving. This allows the car to use less energy and achieve a higher MPG.