How does the Audi A2 achieve such impressive fuel efficiency?

I've noticed that the Audi A2 has a remarkable fuel efficiency rating for its class, but what technology or design elements contribute to this achievement? I'm looking for a specific explanation of how this car is able to achieve such impressive results.

The Audi A2's efficient design is due to its lightweight aluminum construction, which reduces overall weight and improves fuel efficiency. Additionally, the car uses a direct injection engine and regenerative braking system that further contribute to its low fuel consumption.

One of the key factors in the Audi A2's fuel efficiency is its aerodynamic design, with a drag coefficient of just 0.25. This means less resistance and better gas mileage. The car also uses start-stop technology to automatically shut off the engine when not in use, saving even more fuel.

The Audi A2 also employs an efficient transmission system, with a continuously variable transmission (CVT) that allows for smoother gear shifts and better fuel economy. Additionally, the car utilizes an advanced thermal management system that ensures the engine stays at the optimal temperature for efficiency.