2007 Audi S6 Review

Specifications

German Efficiency, Italian Soul

No doubt, 2006 will go down in history as the year Audi returned to the performance fore. With the amazing RS4 leading the charge, it would appear the brand that made their name dominating the worlds rally circuits has finally returned their attention toward the world of class-dominating sport models. The RS4, recently made available, recognized by many as the fastest way up or down any given road, with the soon-due S8 an easy contender for the top spot among the worlds fastest full-size luxury sedans. But what about the A6 series?

After all, the last generation A6 bore the RS6, previously Audis top performing model. With a twin turbo V8 pushing 450 horsepower to all four wheels, the mid-level luxury/sport sedan was an efficient M5-crushing machine only criticized for its almost perfect performance. Never putting a foot wrong, the RS6 simply went where you pointed it as quickly as your right foot commanded. But when Audi revamped the A6 lineup in 2004 the RS6 went the way of the dinosaur, which now leaves a rather large gap between the RS4 super-sedan and upcoming S8, Audis performance-oriented luxury cruiser.

This will all change for the 2007 model year, mind you, with the debut of Audis new S6. A balance of luxury and performance that slots directly between the hardcore RS4 and S8, the S6 is the culmination of Audis continued collaboration with sports-car subsidiary Lamborghini. Just as with the 2007 S8, Lamborghinis largest contribution to the S6 is in the form of a new V10 engine sourced from the Gallardo. Retuned and enlarged to suit the more laid-back nature of Audis sedan format, the formidable powerplant isnt as powerful as the Lamborghinis, with a peak horsepower figure that is a full 100 horsepower below the Gallardos, although a broader torque curve and horsepower spread than the hard-edged Lambo motor should make for a more tractable sedan.

That trade-off comes courtesy of Audis hallmark FSI direct fuel injection, which is said to make the S6 infinitely more drivable than the high strung supercar, placing 397 lb-ft of torque at the drivers disposal, maximized at only 3,500 rpm as opposed to the Gallardos 4,500 rpm.

Beyond the stratified fuel injection system, though, the engine remains largely the same as that found in the Gallardo, with the largest difference being the Audi-tuned mills slightly larger bore rendering a the higher displacement.

The block itself is produced by low-pressure die-casting from a hypereutectic aluminum alloy that makes separate cylinder liners superfluous, the hard hypereutectic aluminum alloy need only be bored and honed to prepare it for aluminum pistons that will squeeze the mixture to an atmospherically high 12.5:1 compression ratio. A balancing shaft located within the engines valley smoothes out its overall operation, and the four camshafts can be adjusted continuously through 40 crank degrees depending on engine load and speed to facilitate better filling of the combustion chambers and improve throttle response.

But for all the technology and mechanical wizardry contained within the 485 lb lump, the off-the-line performance figures are underwhelming, with Audi quoting a 0-60 mph time of 5.1 seconds. Surprisingly high, that figure is a full seven tenths off the time set by the previous RS6 (which boasted only 30 horsepower more), and even lags behind the much larger 2007 S8, which Audi claims will complete the sprint in five seconds flat. Mercedes E55 and BMWs M5 are faster yet, with times in the mid to high four second range.

But that relatively slow acceleration time isnt for lack of traction; fitted with Audis capable Quattro all-wheel drive system, the S6 should be a corner-carver of the first degree. Fed power by a 6-speed Tiptronic transmission, the latest generation of the Quattro system is set up with a basic bias of 40 percent front and 60 percent rear, with the capability of changing that torque split to a maximum of 85 percent rear or 65 percent front. That rear-bias is designed to enhance the sporting nature of the car, while Audis Electronic Differential Lock (which works by applying the brakes on any wheel that is sensed as spinning) works with both stability and traction control systems to keep the most sporting of A6s on the road. Should the driver want to curtail the computers intervention, the S6s ESP button allows him (or her) to do so; with a single press deactivating the traction control and a longer, three-second hold-down turning off the stability and traction control systems; something thats impossible in a normal A6.

Riding on a suspension setup thats very similar to the S8s (in fact, the rear suspension was lifted directly from the larger sedan), the S6 departs from its larger brother in the method of suspension; opting for steel as opposed to air springs. With higher rate springs and firmer dampers the S6 promises to be an even firmer ride too, with Audi promising the S6 will provide a more sporting (read: firmer) ride than even a sport suspension-equipped A6. Likewise, firmer suspension bushings will undoubtedly provide a more precise feel, and Audis Servotronic variable ratio steering has been tuned for more precise feel and direct response to capitalize on the newfound agility. All of this is constructed from various aluminum bits to lighten the unsprung mass and increase the suspensions ability to react to changing road surfaces, while sheet steel pieces provide plenty of stiffness where needed. Large 15.1 inch front and 13.1 inch)discs are clamped by some serious calipers that have been painted black to match the S6s low-key looks, and the whole shebang ends with a set of 19-inch wheels mounting 265-series tires.

Visual differences between the S6 and its slower siblings are kept to low-key enhancements, with the most noticeable changes residing at the front end. The new Audi gets a single-frame grille boasting a shiny new S6 emblem, plus the vertical aluminum-look grille slats have been doubled for further differentiation. The lights are different too, with the S6s new LED parking lamps giving the car a very distinct front end with the lights on. Those LED lights displace the fog lights, which have been moved into the headlight housings behind the S6s unique tinted light covers that also play host to Audis Bi-Xenon adaptive headlight system.

Moving back, the fenders have obviously been flared, extending 0.5 inches further out than the stockers to give the big wheels more room to move, and the side view mirrors have been given the traditional Audi S-line chrome treatment. Less obvious, the door trim strips have been widened, with simple V10 badges living on the fenders below the side marker lights. A stubby spoiler and contrasting diffuser reside at the rear, supplemented by quad ellipsoidal exhaust tips and a single S6 badge. 

Inside, the S6s understated athleticism continues, with only a few minor enhancements to the A6s already luxurious interior. The seats, first and foremost are all covered in Silk Nappa leather, with those in front being more heavily bolstered than regular A6 seats. The steering wheel displays the “S” logo and the stitching is of a contrasting color, while the shift paddles retain their familiar aluminum-look finish; echoed on the leather-trimmed gear selector. Birch Gray wood trim is standard on all S6s, while carbon fiber is optional and contrasts well with the unique “Flexmetallic” instrument panel finish. Finally, the S6s gauge pod is changed slightly, with dark gray gauge faces sporting S6-specific white numbers to keep the driver apprised of just how nasty a speeding ticket theyll get if a cruiser can ever catch up.

While the S6 wont quite fill the void in the Audi lineup left by the RS6, its balance of luxury and performance should be appealing to buyers. Fitting quite nicely between the RS4 and the more luxurious S8, the S6 provides a bit of both worlds without being overwhelming. So while the sportier RS4 should provide a worthy competitor to the upcoming M3, and the 2007 Audi S8 promises to give the M-Bs S55 AMG a run for its money, the S6 disappoints in comparison to the M5. Defeated on all fronts by the technological tour de force that bears the blue and white propeller symbol, the S6s quick but not quite competitive performance figures bode well for a possible RS6 model that would take the Audi performance crown back from the BMW, not to mention the new A4-based RS4. Until such a super sedan is announced, the S6 compromise between all-out performance and luxury touring should make it a popular choice among those looking for an all-wheel drive, all-weather capable sport sedan.