2013 Audi S6 and Audi S7: Motoramic Drives

Stretching its legs on a run to the Bodensee — the Alpine-ringed, fairy-tale lake in Bavaria — the Audi's speedometer sweeps ever higher: 250, 260, 270 kilometers per hour. It's a testament to the giddy, unleashed glories of Germany's Autobahn, but also to the creamy nonchalance of Audi's latest luxury rockets, the 2013 Audi S6 and S7.

Translated into American numbers, the S6 sedan I'm piloting reaches 170 mph before I back off the throttle. And even at that bullet-train pace, the Audi remains as comfy, quiet and planted as Dad snoozing in his Barcalounger.

The production 2013 S6 and S7 that reach showrooms this fall will be electronically limited to just 155 mph; still plenty quick for American drivers and our laughably timid legal limits. But in any language and any market, the S6 sedan and its gigolo brother, the S7 Sportback, are just the latest Audis whose sophisticated design, performance and technology have made Audi a trendsetting force in luxury cars.

For this pair, the 3.0-liter supercharged V-6 of the standard A6 and A7 is switched for Audi's new, 4.0-liter V-8 with direct injection and a pair of twin-scroll turbochargers. Power jumps to 420 hp, up from 310, with torque peaking at 406 ft-lbs. The outgoing version of the S6 was equipped with Audi's 5.2-liter V-10. That detuned version of the Lamborhghini Gallardo engine made slightly more power and slightly less torque than the new V-8. But the new engine, with a helping hand from Audi's dual-clutch, seven-speed S Tronic automated manual transmission, makes the new S6 and S7 decidedly faster yet 25 percent more fuel efficient than the old V-10 model.

Audi says the S6 rips off a stoplight-to-60 run in a fiery 4.5 seconds, or 4.6 seconds for the S7, which weighs 110 lbs. more. Those times are at least a half-second quicker than the previous S6.

Yet unlike most competitors from various high-performance divisions, including BMW's M, Mercedes' AMG and Cadillac's V-Series, Audi's "S" might stand more for "Subtle" than "Superman." These Audis largely eschew flashy costumes and earth-shaking engines. (Audi saves maximum potency for its RS-badged models, including the RS5 coupe coming to America later this year).

Even at full throttle, the Audi's V-8 emits a rich-but-distant baritone hum, not the NASCAR-esque blare of a Mercedes AMG. And that's exactly how Audi wants it. These are born autobahn cruisers — or interstates, in our case — designed to gobble up miles at a wicked pace, but in supreme comfort and safety.

Relative fuel efficiency is aided by cylinder deactivation system that shuts down four of eight cylinders when you're not hammering the gas. The Audis should post roughly 17/25 mpg in city and highway driving, not bad for 420-hp cars that tip the scales at 4,400 to 4,500 lbs. -- and a big jump over the previous S6's 14/21 mpg rating. As with BMW, Mercedes and other brands that are switching en masse to downsized, turbocharged powerplants, it's hard to argue against engines that simultaneously boost power and fuel economy, just because they don't sound as badass.

Only European buyers will benefit from the engine stop/start system, which isn't coming to U.S. models. Nor will Yanks see the optional ceramic brakes, or one especially lovely offshoot: The S6 Avant wagon that I tested and adored, but that Audi rightly realizes would find only a few hundred American buyers, at best.

But if you can imagine another technology or gizmo, the Audi probably has it covered. Beneath its relatively lightweight aluminum body, the Audi features standard Quattro all-wheel-drive, an adjustable air suspension, and a new, NASA-complex sport differential that can instantly shuffle torque side-to-side between the rear wheels.

Remarkable interior silence is defended by noise cancelling technology that uses four microphones and speakers to monitor and wash away unwanted frequencies. Active engine mounts, filled with hydraulic fluid, keep engine vibration to a minimum.

As with its regular-strength versions, the S6 and S7 are among the world's only production cars that work as wireless hotspots, via the cellular-based Audi Connect service that also includes Google Earth views for navigation and a variety of apps and services. With no fuss, we linked an iPad to the network, bringing a whole new meaning to high-speed Internet browsing — for the passenger, of course. And the Audi can connect up to eight wireless devices.

The cabin doesn't disappoint, including sport seats with racy integrated headrests and gorgeous diamond stitched leather (in a choice of black or silver) that recall the thrones of Bentley — like Audi, another luxury vassal in the Volkswagen Group. They're deluxe enough for Kanye West's backside.

Every new Audi, it seems, has to offer an interior feature that dazzles the eye and starts conversations. For these cars, it's the stunning interior trim that layers bright slivers of aluminum within stacks of black wood veneers. The effect recalls a bespoke, pinstripe Tom Ford suit. Plainer aluminum trim is also available, but why bother?

These S models also offer all the toys from their lesser cousins. And that's a lot of toys: Night vision assist, blind-spot and lane-departure monitors, 360-degree surround view cameras, a color head-up display, adaptive cruise control, a collision warning and pre-braking system Audi's stellar Bang & Olufsen audio system, with 15 speakers and 1,200 watts, will be a pricey option.

While Europe's ubiquitous, diesel-powered subcompacts played their oompah tune on the Bavarian autobahn, we rocked hard to the Bodensee, also known as Lake Constance: A 39-mile long lake that skirts the northern edge of the Alps, connected by the Rhine river, and sharing borders with Germany, Switzerland and Austria.

Surrounded by so much beauty, natural and manufactured, it was still possible to find a few faults. Audi's S Tronic transmission, while smooth, swift and smartly programmed, still produced the occasional clunk or hesitation at slower speeds, a condition familiar from other dual-clutch units. And Audi's Drive Select system, which adjusts the engine, transmission, suspension and steering, still operates over too narrow a range. The Auto setting proved the just-right level between the porridge-like steering and ride of "Comfort" and the sportiest "Dynamic" setting. So most drivers will goof with the buttons for about two days before leaving it permanently in "Auto."

And while our Audi's massive 20-inch wheels (19s are standards, suspension and torque-vectoring differential produce remarkable traction and confidence, there's not much in the way of steering feel. But again, this car is largely designed to take the drama out of high-speed driving, not to add more.

Pricing for America has yet to be set, but extrapolating isn't too hard: The regular-strength A6 starts at $50,575, with an A7 at $60,125. Expect a roughly $72,000 base price for the S6, or $81,000 for the S7. Count on one thing: Audi will maintain a roughly $9,000 spread between the S6 and S7. And as with the standard A6 and A7, it's worth asking why adding a hatchback to a car (along with a few minor standard features), makes it worth $9,000 more than the sedan.

The answer, I'm convinced, is that few people would bother with the 6 sedans if the 7's — not only sexier, but more practical -- only cost a few thousand more. Consider the S7's high sticker the price of high style at Audi: Take it or leave it.

The manufacturer provided transportation and lodging for this review