First Drive: 2007 Audi S6

05/01/2007

Shahed Hussain

We had a short stint on the track in the Audi S6 recently. Put simply, this is no normal A6. The differences go well beyond the Lamborghini-derived V-10 engine to include suspension, wheel, and tire upgrades. Consequently, the $72,000 S6 is priced well above the V-8 powered A6 4.2, which starts at $55,300. In Audi's midsize lineup, the A6 4.2 is the sedate cruiser, whereas the storming S6 aims for the affluent enthusiast.

Other German super sedans with similar specifications include the $82,500 BMW M5 and $85,375 Mercedes-Benz E63 AMG, but both of these autobahn cruisers cost considerably more than the S6, and neither offers AWD. Where the S6 does come up short to the BMW and Mercedes-Benz is in the power department, where its 435-bhp V10 is trumped by the 500-bhp V-10 under the hood of the M5, or the 507-bhp from the 6.3L V-8 that motivates the E63. Ironically, the closest competition to the Audi is actually from Cadillac. The $77,855 STS-V, with its 469-bhp 4.4L supercharged V-8 mated to a 6-speed automatic, certainly has the necessary performance credentials. However, the RWD STS-V is more luxury oriented than the S6, so ultimately the Cadillac isn't a direct rival to the Audi.

Audi added a few interior upgrades for the S6, including a set of multi-adjustable Nappa leather sport seats, plus optional carbon fiber inlays on the center console and dashboard (grey birch wood is standard). To remind drivers that this is no ordinary A6, Audi stitches S6 logos on the seats. We expected a set of aluminum pedals, but were disappointed to find just normal rubber pedals instead.

Start up the S6, and the distinctive V-10 exhaust note immediately stands out. Blip the right pedal, and the pistons race with a metallic thrum like a short stroke inline-4, but more menacing. The V-10 lacks a midrange or top end surge, but instead makes smooth, progressive power all the way to the 7,000 RPM redline. Audi claims the 0-60 MPH sprint takes just 5.1 seconds, with a ΒΌ mile time of 13.4 seconds. The S6 will keep accelerating to an electronically limited 155 MPH.

To bring the S6 to a halt, Audi specifies massive 15.2-inch ventilated front rotors, backed up by 13.0-inch ventilated rear rotors. We found the brakes powerful and confidence-inspiring as they hauled the S6 down repeatedly from 100+ MPH. Standard 19" x 9' alloy wheels shod with 265/35R19 performance tires provide superb grip. Optional 255/40R18 tires on 18" x 8.5" alloy wheels are available. Audi uses its familiar 4-link front suspension and trapezoidal link rear suspension; appropriately tightened up with firmer settings compared to the A6. We found suspension tuning well suited for fast laps around the track, but not too stiff for everyday use. Despite the 59/41 F/R weight distribution, mild understeer dominates regardless of throttle input. We didn't really push the upper handling limits during our track time, but despite its hefty 4,486 lbs. curb weight, the S6 feels almost as nimble as the much lighter S4.

Audi's quattro AWD system automatically transfers power between the front and rear axles via a mechanical locking center differential. Although the normal front/rear torque split is 40/60, the center differential will funnel up to 85% of available torque to the rear axles, or route 60% to the front axles. Audi uses EDL (Electronic Differential Lock) to individually brake each wheel to eliminate slip. The ESP stability control can be turned off in two steps. Hit the ESP button once, and the ASR traction control turns off, but the ESP remains active. Press the ESP button for three seconds, and the ESP turns off, but ABS and EDL are still available. To restore all ESP functions, press the button one more time. Customizable ESP functions allow drivers of varying skill levels to experience all the S6 has to offer.

Like other A6 models, the S6 is equipped with a 6-speed Tiptronic automatic, but Audi optimized it for faster shifts. Choose the "S" mode on the shift console for higher-RPM upshifts, or tap the steering wheel-mounted paddle shifters to conveniently zip past slower traffic. We found that the revised automatic provides fast, smooth shifts at any RPM, although a 6-speed manual would be even nicer.

In our experience, Audis usually have heavy, slightly numb steering. For the S6, the engineers designed a new steering rack with vehicle speed sensitive power assist. With only 2.49 turns lock-to-lock, the faster ratio rack enhances turn-in response. The net result is light, communicative steering unlike any Audi we have driven.

We really enjoyed our drive in the S6, which turned out to be a surprisingly lively sports sedan. Audi strategically priced the S6 well below the comparable BMW M5 and Mercedes-Benz E63 AMG. Both of these competitors have more power and arguably more prestige, but neither has AWD, which makes them fair weather companions. We think that S6 will appeal to discerning enthusiasts who value the all-weather capabilities that only this Audi offers.