Why is the Audi A2's fuel economy better than other cars in its class?

I've been looking at different cars in the hatchback category and noticed that the Audi A2 has a much higher fuel economy compared to its competitors. Can anyone explain why this is?

The Audi A2's fuel economy is due to its lightweight design and advanced aerodynamics. This allows it to use less fuel while still having strong performance.

I've owned an Audi A2 for several years now and can confirm that the fuel economy is one of its best features. It's not just good on paper, but also in real world driving.