How does the Audi A1's four-wheel drive system work?

I am interested in purchasing an Audi A1 but want to know more about its four-wheel drive capabilities. Does it work all the time or only when needed? Are there different modes available?

The Audi A1's four-wheel drive system, called Quattro, works by constantly monitoring the car's traction and distributing power to each wheel accordingly. This provides increased stability and performance, especially in slippery conditions. There are different modes available, including a sport mode for enhanced handling.