How does the Audi A2's lightweight aluminum construction contribute to its fuel efficiency?

I'm considering purchasing an Audi A2 and I've heard that its lightweight aluminum construction is what sets it apart from other cars in its class in terms of fuel efficiency. Can you explain how this works and how it affects the overall performance of the car?

Aluminum is much lighter than traditional steel used in car construction, which means the Audi A2 has a lighter overall weight. This directly translates to better fuel efficiency, as the car doesn't have to work as hard to move its own weight. Additionally, the lightweight construction also allows for better handling and agility on the road.