How does the Audi A7 achieve its impressive fuel efficiency?

I've heard that the Audi A7 is one of the most fuel efficient luxury cars on the market. Can you explain the specific features and technologies that contribute to its high fuel efficiency ratings?

The Audi A7 is equipped with a start-stop system, which shuts off the engine when the car is stopped in traffic or at a red light. This reduces unnecessary fuel consumption.

The A7 also utilizes a mild hybrid system, which uses a small electric motor to assist the engine during acceleration. This reduces the strain on the engine and saves fuel.

In addition, the A7 has a remarkably aerodynamic design, with a coefficient of drag of just 0.27. This helps reduce the amount of fuel needed to power the car at high speeds.