What is the difference between Audi's Quattro all-wheel drive and the Quattro Ultra all-wheel drive systems?

I am looking to purchase an Audi but I am unsure about the different all-wheel drive options. Can someone explain the differences between the Quattro and Quattro Ultra systems and which one would be better for my driving needs?

The Quattro all-wheel drive system is a permanent all-wheel drive system that distributes power to all four wheels evenly. This provides better traction and handling, especially in challenging driving conditions. On the other hand, the Quattro Ultra all-wheel drive system is a semi-permanent system that primarily operates as a front-wheel drive to save fuel, but can send power to the rear wheels when needed. If you live in an area with harsh weather conditions, the Quattro system would be a better choice. However, if you prioritize fuel efficiency, the Quattro Ultra system may be a better fit.