How does the Audi A1's cylinder deactivation system work?

I've heard that the Audi A1 has a cylinder deactivation system. How does this feature work and how does it impact fuel efficiency and performance?

The Audi A1's cylinder deactivation system is able to shut off two out of four cylinders when the car is cruising at highway speeds and does not require a lot of power. This helps to reduce fuel consumption and emissions, resulting in better fuel efficiency and a smaller carbon footprint.

The system uses a variable valve lift mechanism to deactivate the cylinders, allowing the remaining cylinders to operate at a higher load and efficiency. This means you can still get the performance you want while also saving on fuel.