Since its 2003 redesign, Audi’s top-of-the-line A8 has been easily as good as anyone’s flagship luxury sedan. Now, with the introduction of a mighty, limited-production, V-10-powered S8 version for 2007, Germany’s storied four-ring marque has redefined what it means by top-of-the-line.
2007 Audi S8Enlarge Photo
The V-10 engine puts the S8 in the same exclusive class as BMW’s M5, Dodge’s Viper SRT-10 sports car, and Lamborghini’s Gallardo supercar. In fact, Audi supplies the Gallardo’s 513-hp V-10 to fellow VW Group member Lamborghini, and this sophisticated, somewhat tamer, 40-valve aluminum ten-holer is a close relative.
Displacing a relatively modest 5.2 liters and boasting FSI (fuel straight injection), Audi’s first-ever V-10 generates a scenery-blurring 450 hp at 7000 rpm in the S8 and 398 lb-ft of torque between 3000 and 4000 rpm, with 90 percent of that available as low as 2300 rpm. While the BMW, Viper, and Lambo V-10s deliver 500 ponies or more, this one trades some raw power for luxury-appropriate refinement. Its fuel is high-pressure-injected directly into the cylinders, its magnesium, two-stage variable intake manifold breathes through two separate air paths with twin air filters, and its four chain-driven overhead cams are continuously hydraulically adjusted.
All wheels involved
All this energy is fed to the pavement through a standard “Tiptronic” six-speed automatic and quattro permanent all-wheel drive. There’s no available manual gearbox, but you can manually shift the automatic, surprisingly quickly and precisely, either by flicking the leather-wrapped shifter fore or aft or by thumbing the aluminum-look steering wheel paddles. The transmission’s “S” (sport) mode holds its shifts to higher engine speeds, and the paddles work whether or not the lever is in its manual slot.
Under normal conditions, Audi’s latest quattro system routes 60 percent of driving torque to the rear wheels and 40 percent to the fronts through a self-locking center differential, but when conditions warrant, it can instantaneously adjust from up to 85 percent rear to as much as 65 percent front. When traction control may be counterproductive or simply unwanted, you can push a button to deactivate it or push and hold it for three seconds to disable all elements of the standard stability control except the anti-lock braking and the electronic differential lock.
The S8’s transmission, steering, chassis, and brakes are appropriately upgraded for such prodigious power, and it rolls on beefy 20-inch alloy wheels wearing 265/35 R20 high-performance (three-season) tires. Its mostly lightweight aluminum suspension is four-link in front and a self-tracking trapezoidal-link design in the rear, which improves steering precision and directional stability by reducing rear bump toe-in as the springs move through their range of travel. Its rigid aluminum space frame and body significantly reduce its weight, while the standard adaptive air suspension lowers it and tightens the steering at highway speeds.
Advertising those cylinders
The S8 is distinguished from its “ordinary” A8 cousin by a bold eggcrate grille, and with LED daytime running lights (DRLs) allotted five-to-a-side — like its cylinder count — in Gatling-gun arrays inside its headlight clusters. Bi-xenon adaptive headlights, which turn with the steering to light up more road during cornering, and LED brake lights are standard. V-10 badges grace its flanks, while a subtle spoiler and quad oval exhaust tips (smaller than we think they should be) enhance its going-away view.
2007 Audi S8Enlarge Photo
Audi is known for simply designed but beautifully executed interiors, but this quiet, commodious cabin is at once much plusher and more complex than its usual fare. The three-spoke steering wheel, complete with audio controls and power tilt and telescope adjustments, is trimmed in smooth leather with beautifully detailed stitching. Standard interior trim is gray birch wood, but shiny (plastic-looking) carbon fiber is optional, and the 16-way seats are Valcona leather. Audi’s big-knob Multi Media Interface (MMI) system controls most major functions, but it’s much less annoying and more user-friendly than BMW’s infernal iDrive.
Deep pull-out door bins, DVD-based navigation and Bose Surround Sound premium audio (with its six-disc CD changer hidden in the extra-large glovebox) are standard. Optional for a whopping $6300 is a Bang & Olufsen Advanced Sound System with 1000+ watts and 14 speakers, each with its own tiny amplifier, two of which are high-frequency tweeters that pop out of the dash like boxy metallic gophers.
We enjoyed a rare opportunity to exercise the A8 on city freeways and lovely, hilly, twisty two-lanes north of Montreal, Quebec, and we came away thoroughly impressed. The V-10’s carefully tuned sound alone is nearly worth the $92,000 price of admission. Other V-10s can sound harsh, even tinny, but this one bellows a glorious, throaty muffled roar that’s well matched to the lusty thrust it produces when you step into the right pedal. The steering is perfectly weighted and responsive, the brakes powerful and sure, the ride motions beautifully damped as the big tires grip, the suspension takes a set, and your thumbs call up exactly the right gear to power through corners slow, fast, and sometimes ruggedly rough.
Audi invests time and money to develop such powerful, athletic S models (including the V-8-powered compact S4, the faster-still RS4, and the also V-10-driven S6) for three good reasons: to provide sensuous driving joy for affluent enthusiast buyers; to demonstrate its high level of technical competence; and to “conquest demanding new customers.” Though it will be both costly and rare, with only 1000 planned for the U.S. market, we’re confident this sinfully powerful S8 will be up to all three key assignments.
2007 Audi S8
Transmission: Six-speed Tiptronic automatic, all-wheel drive
Length x width x height:
199.3 x 74.7 x
Wheelbase: 115.9 in
Curb weight: N/A
Fuel economy (EPA city/hwy): 15/21 mpg
Major standard features: All-wheel drive; adaptive air suspension; Servotronic vehicle speed-sensitive steering; bi-xenon adaptive headlights; high-pressure headlight washer; Bose premium audio with six-disc CD changer; dual-zone automatic climate control; 16-way power heated front seats; power adjustable steering column; power glass sunroof; universal phone prep with Bluetooth wireless capability; DVD-based navigation
Safety features: Anti-lock brakes, stability and traction control; dual front, side, and curtain airbags; rear side airbags; seatbelt pretensioners and force limiters
Warranty: Four years/50,000 miles