We’ve already done previews on them. Now, we can reveal the new Audi S6, S7 and S8 in all their glory. Some may question whether there’s in fact a need for all three, but with Audi seemingly hell bent on filling every niche possible in the market, they’re with us nonetheless.

Of course the biggest news concerns the engines that power them. All three will feature a version of Audi’s 4.0-liter twin turbo V-8, rated at 520 metric horsepower (PS) in the A8 flagship and 420 PS in the A6 sedan, Avant and S7 Sportback.

The key behind the switch to the new engine (especially in the S8) has been driven by the need to improve fuel economy (reportedly reduced by around 25 percent) while maintaining a healthy dose of performance.

According to official stats from Audi, the new 2012 S6 will sprint from 0-100 km (0-62 mph) in just 4.8 seconds; the S7 in 4.9; while the S8 will do the same jaunt in just 4.8 seconds. All three cars are limited to a stop speed of 155 mph and are said to return at least 27.7 miles per gallon (Imperial) in terms of fuel economy.

A big development is Audi’s displacement on demand system, which shuts off four-cylinders under light throttle openings; and as we’ve reported before Active Noise Cancellation, which incorporates a computer activated antiphase sound to cancel out any unwanted cabin din.

All three cars feature Audi’s quattro system with self-locking center differentials as well as adaptive air suspension and seven speed automatic transmissions on the S6 and S7 (the S8 features eight speeds).

Although slated for European delivery first, don’t expect it to be that long before the S6, S7 and S8 show up here, though odds are, the S6 Avant wagon probably won’t make the cut.

Set for its official reveal at the Frankfurt Auto Show in just two weeks time, Audi will launch an all-new S8. Discontinued in 2010 with its Lambo-s0urced V10, the 2012 model trades displacement for turbochargers, with a new twin-turbo 4.0-liter V8 making an impressive 520-hp and 480 lb-ft of torque, an improvement of 70-hp and 80 lb-ft.

Using Audi’s quattro AWD and an 8-speed automatic transmission the new S8 can hit 62 mph in just 4.2 seconds. In addition, Audi claims a fuel economy improvement over the outgoing model of roughly 23 percent. This is due in part of a start-stop system, brake energy regeneration and a “cylinder on demand” technology that allows the engine to operate on just four cylinders when under light load.

For idea performance the S8 comes standard with Audi’s sport rear differential, distributing most of the engine’s torque to the inside rear wheel in a corner. Other handling and performance goodies include an adaptive ride air suspension and dynamic steering that are tied into the Audi Drive Select system with five driver-selectable modes: comfort, auto, dynamic, individual and efficiency.

Sticking the S8 to the road are standard 20-inch wheels and tires with big brakes. Carbon ceramic brakes are optional.

Outside the car is distinguishable by a platinum gray front grille with an aluminum-look font splitter, signature aluminum-look mirror housings, and the same paint treatment on the rear diffuser. Plus, look for S8 or V8T badges. And inside the S8 gets the usual array of sporty accoutrements, with Audi’s incredible level of luxury, as well as high-tech safety and convenience goodies like Audi’s MMI system, adaptive cruise control with stop and go, Audi’s new pre sense system that can alert the driver of an impending collision, or if he/she is dozing off.

Look for more on the 2012 Adi S8 when it debuts at the Frankfurt Auto Show on September 13th.

GALLERY: 2012 Audi S8

Destined for dealers some time in 2012, the Audi S8 could debut as early as the Frankfurt Auto Show this Fall. Along with what will no doubt be the largest grille ever fitted to a production car, the S8 will be powered by the company’s new turbocharged 4.0-liter V8 engine making an impressive 520-hp.

Past S8 iterations were less than impressive with a naturally aspirated Lamborghini V10 that was harder on your wallet than it was on the asphalt. The new high-torque engine with Audi’s new lighter chassis should make for an impressive turnaround for the car, especially when equipped with the usual S goodies, like larger wheels, upgraded brakes and a stiffer suspension.

Look for a sticker price above $100,000.

[Source: Car & Driver]

With Audi having just launched its all-new 2011 A8 luxury flagship sedan and fuel efficient diesel and hybrid models put on display at last week’s Geneva Auto Show, the next step for the big grilled saloon will be a high-performance model. That’s right, the S8 is set to return.

According to a report by Car & Driver, along with a few spy photos of the model caught winter testing, the S8 will forgo the Lambo-sourced V10 (which wasn’t all that impressive anyway) for a twin-turbo V8. Displacement for the new motor is set at 4.0-liters and while power will be about the same at 450-hp, torque will be significantly higher, resulting in much better low-end grunt.

The new turbo-eight will also deliver much improved fuel economy, while the reduced weight over the front axle should help make for a more dynamic driving experience, while keeping the luxo-barge’s overall weight down.

The S8 should arrive as a 2012 model, so expect a debut late this year or early in 2011.

[Source: Car & Driver]