The Audi S6 is a 420 horsepower beast with a zero-to-60 miles per hour time of under four seconds. Staff photo by Mark Kennedy

For the first 5 minutes after this week's test drive of the awesome 2013 Audi S6, I thought my personal car, a Toyota Camry hybrid, was broken.

On the drive back to work, I checked the parking brake on the Camry. I tapped the temperature gauge to see if it might be overheating. I looked down to make sure the floor mat wasn't impeding the accelerator.

Then, truth hit me: When you jump out of a 420 horsepower rocket like the S6 straight into a 192-horsepower family sedan, the sensation is jarring. It's as if you've just hit a patch of quick-sand in your Big Wheel Racer.

Nevermind its mild-mannered styling, the S6 is one of the fastest production cars on the road today. Car and Driver estimates its 0-60 mph time at 3.6 seconds. If you don't study cars, that means things can get small in the rear-view mirror very, very quickly.

Top speed in the S6 is capped 155 miles per hour; although the engine, without its electronic nanny, is capable of 190 mph. Again, 190 miles per hour. Yowee!

Audi Chattanooga sales manager John Adams noted that S6 has a practical side, too. A cylinder shut-off system throttles back the V-8 engine to four cylinders for cruising, a feature that pushes highway fuel consumption to 27 miles per gallon.

STYLING, COMFORT

The exterior of the S6 is similar to the more sedate A6 sedan. But if you look closely you'll clearly see some clues to the beast within.

The first tip-off: Brake rotors the size of large pizzas. Next, you might notice a quartet of chrome exhaust tips that vent the 4.0-liter, twin-turbocharged V-8 engine that powers the S6.

Swept LED headlights, a platinum colored grille and a spoiler in the rear give the S6 a few distinctive styling cues, but otherwise the car is a stealth rocket.

The interior features a distinctive diamond stitching on the leather-covered seats, which also have embossed S6 insignias just under the headrests. As in all Audi cars, the seats hug your body, so you can take on those twisting mountain roads without being tossed about.

Our test car is a beautiful Estoril Blue Crystal color, with Lunar Silver interior. Carbon Atlas inlays, a $500 option, adorn the door panels and center stack, and have a 3-D effect that give the cabin a starship quality.

PERFORMANCE

There are two chances that a typical owner will press the S6's performance limits -- slim and none. But simply knowing that there are 420 horses under the hood has a way of putting a smirk on your face.

The S6 has a throaty growl under hard acceleration that announces it as an alpha dog. People on the freeway tend to give you plenty of room.

On a test drive on twisty backroads near Chickamauga Lake the S6 was grippy and composed in hard cornering. All Audi cars make you feel molded to the cockpit, the G-forces thrown off by the S6 exaggerates the sensation.

BOTTOM LINE

The Audi S6 is a special car, and it's priced accordingly. Our test car carries an MSRP of $77,320.

But if you have the means and like the idea of pulling up to a stoplight, loosening your tie and then blowing the pants off a punk in a muscle car, this might just be your ride.