2001 Audi S4 The gloves are off. By John Matras, New Car Test Drive .com

Audi's A4 is a svelte and sophisticated sports sedan with power and handling to make quick work of most twisty roads. But for some die-hard performance enthusiasts, the basic version is not enough.

Enter the S4, a bulked-up bruiser equipped to take on all comers. Armed with a twin-turbo version of the 2.8-liter V6 used in the larger A6, plus a stiffer suspension and bigger brakes, the S4 is a world-class athlete. Yet true to its German roots, styling cues are subtle, meaning this sedan can go about its business quietly until its driver is ready to rumble.

Audi S4 comes as either a $38,900 sedan, or, new for 2001, an S4 Avant wagon model priced at $40,500. Both versions are available with a choice of transmissions: 6-speed manual or, as a no-cost option, 5-speed Tiptronic automatic.

All S4s come with Audi's quattro all-wheel-drive system, a 250-horsepower twin-turbo V6, massive 225/45R17 tires and leather upholstery.