What is the function of the start-stop system in an Audi A5?

I've noticed that my Audi A5 has a start-stop system, but I'm not sure what it does. Can you explain its function and how to use it?

The start-stop system in an Audi A5 is designed to reduce fuel consumption and emissions by automatically turning off the engine when the car is stopped, such as at a red light. It can be activated by pressing the start-stop button next to the gearshift. When the system is active, the engine will restart when you release the brake pedal. This feature is especially useful in stop-and-go traffic.

In addition to saving gas, the start-stop system also helps reduce wear and tear on the engine and starter. However, if you prefer to turn off this feature, you can do so by pressing the start-stop button twice, which will turn off the system until your next drive. Just be aware that this may decrease your fuel efficiency.