Why do some Audi vehicles have Turbo engines while others do not?

I've noticed that some Audi vehicles, such as the Audi A4, have Turbo engines while others, like the Audi Q7, do not. Why is this the case and how does it affect performance and fuel efficiency?

The decision to include a Turbo engine in a vehicle depends on several factors such as intended use and target market. Vehicles like the A4 are designed to be sportier and appeal to a younger demographic, thus the Turbo engine adds to the overall driving experience. On the other hand, the Q7 is a larger and heavier SUV meant for family use, so a non-Turbo engine may offer better fuel efficiency and longer lasting engine life.