What technology is used in Audi cars for better fuel efficiency?

I recently bought an Audi car and I'm curious about what technology they use for improved fuel efficiency. Can you enlighten me about this?

Audi uses a combination of technologies such as direct fuel injection, variable valve timing, and lightweight materials for better fuel efficiency.

Audi cars also feature start-stop technology, which shuts down the engine when the car is not moving, further improving fuel efficiency.

Audi's TDI engine technology utilizes clean diesel for more power and lower emissions, resulting in a more fuel-efficient drive.