The main difference is the NACA bonnet ducts, adjustable rear wing, and deeper front spoiler. Only 16 were ever produced and sold in Europe.
Need for Speed: Porsche Unleashed
The Porsche 968 Turbo S appears in the PlayStation release of Need for Speed: Porsche Unleashed as a class 1 car for 175,000 Credits.
The Turbo S has a higher acceleration and top speed than the other 968 models, but at the sacrifice of handling.