The S8 is available only on the short-wheelbase A8 platform, which is more than 100 pounds lighter than the stretched version, but it still comfortably seats four adults taller than six feet. Its equipment levels are similar to those of the range-topper A8L W-12 and include amenities such as sumptuous Valcona leather seats with heavier bolsters and an Alcantara headliner. The options list is short, with two new choices: A back-up camera is now part of the $5000 Premium package, and Audi has gotten rid of the distorted fisheye look that plagues many other manufacturers’ displays with post processing. There’s also an astonishing 1100-watt Bang & Olufsen 14-speaker stereo that, for $7800, brings lifelike sound to the cabin.

Like Mercedes-Benz’s AMG and BMW’s M, Audi’s S division serves as Ingolstadt’s in-house tuning firm. Over the past two decades, not the easiest time for Audi in America, the “S” has become a respected badge among enthusiasts, and deservedly so. The 2007 S8, built exclusively from the short-wheelbase (115.9 inches) A8 platform, is intended as the ultra-S in Audi’s stable, gunning for both BMW’s M5 and 760i models, as well as the brawniest S-Class that AMG can throw down.

Naturally, that gunning starts with an engine that builds torque like high schoolers build hormones. For the S8, Audi jumped the fence into Italy, paying a call to Lamborghini — also owned by the Volkswagen Group — to lift the Gallardo’s 40-valve V10 power plant. Audi bored Lambo’s 5.0-liter engine out to 5.2 liters and fit its own FSI gasoline direct-injection technology.

Translated into German, the V10 makes 450 horsepower at 7,000 rpm and 398 pound-feet of torque at 3,500. That 7,000-rpm mark is just a hair off redline and the engine feels strong and steady from just off idle to the top end of the tach. The V10′s got no weak spots, but there’s no place in the powerband where it catches a sudden gust of wind either.

The six-speed Tiptronic automatic transmission and shorter final drive mate well to the engine, although 1st-gear throttle tip-in can be abrupt and disturbing if you don’t baby it. The tranny’s ratios are superbly matched, shifts are sweet and it matches revs well on kickdowns. The S8′s power is best manipulated manually through the steering-wheel shift paddles — that’s the way to get Audi’s claimed 5 seconds to 60 mph. Even in Sport mode, however, the transmission has to be convinced to kick down for serious passing. That kind of second-guessing from your gearbox is not good for the relationship between you and your car.

For all the S8′s changes, however, when we punch the engine-start button and pull away from the InterContinental hotel in downtown Dsseldorf, the overall effect is fairly muted. At startup, and trolling through the city, the V-10 is barely discernible from Audi’s 4.2-liter V-8. The six-speed Tiptronic slips smoothly from one gear to the next, with none of the jerkiness of an auto-shifted manual. The steering is light and relaxed, despite being ten percent quicker off-center. The seats are more aggressively bolstered, but these easily could be the standard chairs.

Gliding onto the freeway that will take us out of the city, we get up to about 60 mph and, visuals aside, we could be driving a standard A8. Like any A8, of course, it’s very nice. The interior is splendid to look at and touch. The controls are not terribly intimidating. Even the knob-and-screen controller, Audi’s Multi Media Interface, is fairly logical, if still distracting. And the relatively lightweight aluminum structure means that, even when laden with all manner of luxury equipment, the S8 avoids the sense of asphalt-crushing deliberate movement that characterizes a BMW 7-series or, certainly, a Volkswagen Phaeton. It’s not constantly reminding you of its hugeness.

Standard Engine:5.2L V10, 40 valve, 450 hp @ 7000 rpm

• 6 speed automatic transmission
• 15 mpg city / 21 mpg hwy
• Green Rating: 51

Standard Features:

• Seat Mounted Front Side Airbags
• 4-Wheel Anti-Lock Brakes
• Digital Signal Processing (DSP) Pre-Programmable Equalizer