How is the engine of the Audi A3 designed for optimal fuel efficiency?

I am interested in the fuel efficiency of the Audi A3 and was wondering how the engine is optimized for this purpose?

The Audi A3 is equipped with a 1.4-liter turbocharged TFSI engine, which is designed to provide an optimal balance of power and fuel efficiency.

The A3's engine utilizes a combustion process that maximizes fuel efficiency while still delivering an impressive amount of power for a vehicle in its class.

Audi has incorporated advanced engineering techniques and technologies, such as direct fuel injection and a start-stop system, to further enhance the A3's fuel efficiency.