Audi S8 -- First Drive: Running backs are fast. Defensive linemen are big. Motorcycles are nimble. Freightliners are cumbersome. Simply put, fast in straight and curvy lines usually correlates with small and lean, while brute power is typified by big and brawny. They seem mutually exclusive to a large extent, but not in the eyes of Audi engineers.

Hence, the creation of the 2007 S8, a sport-tuned A8 last sold in the U.S. as a 2003 model. Thanks to the generous use of aluminum in its construction, the S8 (and A8) is relatively light, which allows its 450-horsepower, Lamborghini Gallardo-derived V10 to be all that much more effective. In fact, that sophisticated piece of hardware, when coupled with S8's standard quattro all-wheel drive and six-speed Tiptronic automatic transmission, allows this most athletic rendition of Audi's flagship to reach 60 mph in only 4.9 seconds. Those are impressive figures, and are sure to catch the attention of large sedan lovers and well-paid executives everywhere, those who won't shy away from the S8's base price of $94,020 when it arrives in November. But they'd best be satisfied with that exceptional straight-line performance, because in the corners the S8 is more oversized linemen than evasive running back. For the total performance package, including outstanding balance and handling, buyers would be best served to take a gander at the smaller S6 sharing space on the Audi showroom floor, or one of the S8's top-notch competitors.