Duritz, both the Range Rover (Vogue) en the Range Rover Sport have supercharged engines available. I think the best way to show the difference is:
Range Rover ( Vogue ) : http://www.caradvice...07082243627_alt
Range Rover Sport : http://files.winding...t-on-the-ro.jpg
So as you can see they are two completely different models.
EDIT: I see you knew about the outside difference.
The Range Rover Sport is designed to have another Range Rover. It's designed on the platform of the Discovery. It also weights 200kg lighter. Both have a supercharged engine available though the one in the sport is a little less powerful.