How efficient is the TDI engine in the Audi A2?

I've heard that the Audi A2 has a TDI engine, but I'm not sure what makes it special. Could someone provide some insight on its efficiency?

The TDI engine in the Audi A2 is known for its excellent fuel efficiency, with an average of 53 miles per gallon in city and highway driving. In fact, it was one of the first cars in its class to receive an energy efficiency rating of A by the European Union.

The TDI engine in the Audi A2 utilizes advanced direct injection technology, resulting in better fuel economy and lower emissions compared to a traditional gasoline engine. As a bonus, it also provides a smooth and quiet ride.

I've had my Audi A2 for a few years now and the TDI engine has been a game changer in terms of fuel efficiency. It's definitely worth the extra cost upfront.