What are the differences between Quattro and Quattro with ultra in Audi models?

I am researching Audi models and noticed that some have Quattro while others have Quattro with ultra. What are the differences between these two versions, and which one should I choose?

Quattro and Quattro with ultra both refer to Audi's all-wheel drive system. The main difference is that Quattro with ultra is designed for fuel efficiency by only engaging the rear wheels when needed, while Quattro provides all-wheel drive all the time.

In terms of performance, Quattro is better suited for dynamic driving and offers a more balanced power distribution between the front and rear wheels. Quattro with ultra is more suitable for everyday driving, providing better fuel efficiency without sacrificing all-wheel drive capabilities.

If you live in an area with inclement weather or do a lot of off-roading, Quattro would be the better choice as it provides constant all-wheel drive. Otherwise, Quattro with ultra would be a great option for everyday use.