I've done bad things. I have committed crimes beyond incessant speeding. I have stolen. I have lied. I have cheated. I may have forgotten to put any of it on my résumé. But I haven't transgressed enough to earn a new S8. This is a villainous luxury car, one so wicked that merely hopping behind the wheel should make you a person of interest to Interpol.

Yes, for the 2013 model year, Audi has recast the S8 as a sedan mastermind, dumping the old model's 450-hp V-10 like a disloyal henchman. The replacement 4.0-liter V-8 is the twin-turbocharged and features cylinder deactivation that allows it to run as a V-4, just like inthe A8. But here it's making 520 horses and 481 pound-feet of torque. That's 100 more horsepower and an additional 75 pound-feet compared with the A8, thanks to more boost (15.9 psi versus 12.3), revised valve timing, and more efficient intake plumbing.

This violent V-8 makes Audi's plot to take over the world likely to happen more swiftly. It goes from zero to 60 mph in 3.6 seconds, needs just 8.5 seconds to reach 100, and tricks through the quarter-mile in 11.9 seconds at 118 mph. Never mind that the S8 is a 4620-pound car that comfortably seats five. It drives a class or two smaller, as if it's been hit with a shrink ray. At times you would swear it's an A4, except for the better steering feel and an exhaust note as heavy as a San Quentin life sentence.

Despite the S8's hyper performance, half the appeal is in its ability to induce amnesia in witnesses. The S8 never has been flashy, and this new model retains the A8's subtlety, drawn to resemble nothing more shapely than a cudgel. Even its interior doesn't offer much to distinguish the S8 from the regular A8, save for standard carbon-fiber and aluminum trim. The latter serves as a reminder of the aluminum-intensive space framethat Audi pioneered in 1994 and that the A8 range, with redesigns, continues to use today.

All that metal (even the speaker grilles on the $6300 Bang & Olufsen audio system are aluminum) led to this stray thought under heavy braking: "If I ball this thing up, they can hose me out and recycle the rest into Pepsi cans." Fortunately, the brakes bite like four vampires, stopping the car from 70 mph in just 156 feet. The S8 shares its anchor hardware from the long-wheelbase A8 W12, with 15.7-inch discs in the front and 14.0-inchers in the rear. A big brake pedal (trimmed in aluminum, of course) imparts an even, progressive feel, with the first quarter of its travel sufficient for stopping without alarming passengers. The rest of its arc forces the six-piston front calipers closed with the sort of seatbelt-straining force that makes your neck hurt.