[thstone]

I'd suggest that its all in the marketing - a guy walks into a Porsche dealer and looks at a base model and then he looks at the S model and the much higher max speedo of the S implies that the S is MUCH faster.

IF Porsche offered a "Turbo S" Boxster, the speedo would probably be marked at 200mph regardless of whether the car could ever reach that speed.

But more likely, the answer will have something to do with a nun, a ruler, and some spanking.