Used 2011 Audi S6

Who wouldn't want a Lamborghini engine under the hood? Well, the 2011 Audi S6 may sound great at full throttle, but otherwise the S6 brings up the rear in the super-sedan segment.

Stuffing a V10 into a midsize luxury sedan sounds like the sort of bonkers thing a billionaire does just because he can -- like plating his refrigerator in platinum or buying Guam. And yet, that is just what has been done with the 2011 Audi S6, as a V10 shared with the Lamborghini Gallardo sports car has been stuffed under the hood of an A6 sedan. Sounds amazing in a nutty sort of way, but unfortunately, the 2011 Audi S6 just doesn't live up to the hype. It's just not quite nutty enough.

For starters, the S6's 5.2-liter V10 might be shared with the Lamborghini Gallardo, but like removing the horns from a bull, the S6 version has 127 fewer horses. It's also down by 100 horsepower compared to the Audi R8's V10. More importantly, though, the 435-hp V10 in the S6 is 75 hp down on the Jaguar XFR and 83 hp down on the Mercedes-Benz E63 AMG. The result is a sedan that gets thumped by its competition and one that barely manages to eke out a drag-race victory over its sibling, the supercharged Audi A6 3.0T.

The issue isn't wholly a lack of power; it's the abundance of weight. With 59 percent of this car's weight hanging over the front wheels, even the S6's all-wheel-drive system with its rear-biased torque split can't save the S6 from speed-scrubbing understeer in the corners. In other words, the sort of high-speed, tire-smoking hijinks that you can enjoy in other super sedans won't be had with an S6. Nor is there any payoff in terms of ride quality, because the S6's standard 19-inch wheels and sport suspension produce a bone-jarring ride.

We will point out that all this is tempered by the fact that the S6 is still powerful, stylish and indulgently luxurious. It is also about $10,000 cheaper than its fellow German super sedans and $3,000 less than the 2011 Jaguar XFR. But Audi's value proposition starts to fall apart when you consider that the 2011 Cadillac CTS-V is priced about $20,000 less.

The 2011 Audi S6 is a high-performance midsize sedan available in a lone trim level known as Prestige.

Standard equipment includes 19-inch cast-aluminum wheels, performance tires, automatic and adaptive xenon headlights, LED running lights, a rearview camera, rear parking sensors, a sunroof, keyless ignition/entry, automatic wipers, auto-dimming and power-folding exterior mirrors, eight-way power front sport seats with driver memory functions and adjustable lumbar, a power tilt-and-telescoping steering wheel, dual-zone automatic climate control, leather upholstery and heated front and rear seats.

Also standard are Bluetooth, a voice-activated navigation system with real-time traffic, Audi's Multi Media Interface (MMI) and a 13-speaker Bose surround-sound system with six-disc CD changer, satellite radio and an iPod interface. Options include 18-inch wheels (no cost), non-sport seats (no cost), rear side airbags and a blind-spot warning system.

The 2011 Audi S6 features a 5.2-liter V10 good for 435 hp and 398 pound-feet of torque. Quattro all-wheel drive is standard along with a six-speed automatic that features manual shift control. In Edmunds track testing, the S6 ran from zero to 60 mph in 5.7 seconds -- barely quicker than the A6 3.0T and woefully slower than the Cadillac CTS-V, Jaguar XFR and Mercedes E63. EPA-estimated fuel economy for 2011 is 14 mpg city/21 mpg highway and 16 mpg combined.

Standard safety equipment on the Audi S6 includes antilock disc brakes, stability control, all-wheel drive, front-seat side airbags and full-length side curtain airbags. Rear side airbags and a blind-spot warning system are options.

In crash tests by the Insurance Institute for Highway Safety, the Audi A6 (on which the S6 is based) scored the highest possible rating of "Good" in both frontal-offset and side-impact tests, but a second-best rating of "Average" in the roof strength test.

In Edmunds brake testing, the 2011 Audi S6 came to a stop in a fade-free 110 feet -- a good result for this type of car.

The 2011 Audi S6 handles well for a nose-heavy 4,500-pound AWD sedan, but it simply can't keep up with the quicker and better balanced competition around corners. It's just not as fun to drive and there's no payoff in terms of ride comfort, either -- the S6's suspension is sports-car stiff.

As good as the V10 sounds, it doesn't produce the thrust needed for the S6 to be competitive in this rarefied high-performance segment, and the six-speed automatic isn't as responsive as the dual-clutch automated manual gearbox found in the Audi S4.

Trimmed in leather and aluminum with birch wood accents, the S6's cabin carries on the Audi tradition of finely wrought interiors. The amply bolstered front sport seats provide good support during aggressive driving, though if you dislike that hugged feeling, the A6's normal seats are a no-cost option. Interior room is spacious, with plenty of room for four passengers to travel in long-distance comfort. The trunk offers 16 cubic feet of space, which is pretty good for this size of car.

The S6 comes with Audi's latest MMI, which controls entertainment, communication and optional navigation functions via the dash-mounted LCD screen and center console-mounted controls (a knob and buttons). Though there is still a bit of a learning curve involved in using it, MMI has been dramatically improved in recent years, especially in regards to navigation functionality.