Audi S6 Avant (2006)

A ten-cylinder engine is the ideal design for realising sporting aspirations. It has the edge on a comparable twelve-cylinder unit thanks to the smaller number of components, resulting in lower moving masses and less internal friction; the fuel is consequently put to very efficient use. A V10 is moreover considerably lighter and more compact than a conventional 12-cylinder engine - including all its add-on components, the engine of the Audi S6 is just 685 millimetres long, 801 mm wide and 713 mm high. The bare engine measures 560 mm in length.

Although an eight-cylinder engine would be even more compact, to make it into the five-litre-plus class it would need large, heavy pistons and connecting rods, so its ability to rev freely would be impaired as a result. It is no coincidence that many competitors have generally concentrated simply on high torque with their large-capacity V8 engines, rather than attempting to squeeze sporty performance out of them too.

The 435 bhp V10 in the Audi S6 belongs to the next generation of Audi V-engines, all of which have a 90-degree included angle and a spacing of 90 millimetres between cylinder centres. Its two banks of cylinders are offset by 18.5 mm.

Key areas of the Audi version have been reengineered compared with the engine in the Lamborghini Gallardo. The bore, for instance, has been increased from 82.5 to 84.5 millimetres. Its stroke is 92.8 mm, and its displacement 5,204 cm3.

The crankcase of the Audi ten-cylinder engine is produced by low-pressure die-casting, from a hypereutectic aluminium alloy. This technology renders separate cylinder liners superfluous; the cylinder barrels are instead honed directly from the material by mechanically exposing the hard silicon crystals. A so-called bedplate design - an intermediate frame - gives the crankcase extremely high torsional rigidity and improves its vibrational behaviour. Its cast-in bearing bridges, made from grey cast iron, reduce thermal expansion and keep the amount of play at the main crankshaft bearings within tight tolerances.

The high-strength connecting rods are made from forged steel, and the pistons from an aluminium alloy. At the rated engine speed, each of them covers an average distance of 21 metres per second. With its crankpin offset of 18 degrees, the V10 fires at the ideal spacing of 72 degrees crankshaft angle. A balancing shaft located between the cylinder banks eliminates the free inertial forces of the first degree and also contributes towards the engine's notable refinement.

All four camshafts of the ten-cylinder engine (two per cylinder bank - the DOHC principle) can be adjusted continuously by 42 degrees crankshaft angle via hydraulic camshaft adjusters, depending on the load and engine speed. In this way, filling of the combustion chambers is optimised across the entire engine speed range and the engine response is enhanced.

The camshafts - complete with the balancing shaft, the oil and water pump and the auxiliaries - are driven by maintenance-free chains running on the reverse side of the engine.

The valves - 40 in total - are actuated via roller cam followers with hydraulic valve-play compensation.

The diameter of the valves on the intake side is 32.5 millimetres, and 28.0 mm on the exhaust valves. The highly-loaded exhaust valves are sodium-filled, which ensures a better cooling effect.

The V10 in the Audi S6 uses the FSI petrol direct injection principle; this permits a high compression ratio of 12.5:1 and a correspondingly effective combustion process.

FSI technology has impressively demonstrated its dynamic potential in motor sport - the R8 racing car equipped with it participated in the Le Mans 24 Hours five times for Audi, emerging as the winner on four of those occasions.

In the Audi S6, the FSI technology is managed by a highly advanced Bosch Motronic bearing the designation MED 9.1, operating with two separate control units according to the master/slave principle.

Unlike conventional indirect manifold injection, the FSI common rail injection system injects the fuel directly into the combustion chambers in precisely metered amounts, at a pressure of up to 100 bar. This results in an extremely homogeneous fuel/air mixture, benefiting the efficiency of the combustion process. An internal cooling effect moreover takes place, allowing the engine's basic compression ratio to be raised to a high 12.5:1. A highly efficient combustion process is the result.

The magnesium two-stage variable intake manifold is respirated via two separate air paths with two air filters. The variable intake manifold incorporates electronically controlled tumble flaps that induce a tumbling motion in the air drawn in at low engine speeds and loads; this enhances the efficiency of the combustion process inside the engine even further.

The two-stage layout of the magnesium intake manifold serves the same purpose. Depending on the load and engine speed, the longer manifold length (675 mm) is activated to provide ample torque at low and medium engine speeds, and the shorter manifold length (307 mm) to ensure high power output at higher engine speeds.

The design of the single-pipe manifolds likewise contributes to the dynamically optimised charge cycle; it is matched precisely to the firing order of the V10. On each cylinder bank, the exhaust ducting of the first and second cylinder and of the fourth and fifth cylinder is combined; it only converges with the exhaust ducting of the third cylinder relatively far down. Four main catalytic converters take charge of exhaust emission control.

The powerful ten-cylinder engine has been optimised for high torque as well as high engine power. It achieves 435 bhp (320 bhp) at 6,800 rpm, and musters up 540 Nm of torque at engine speeds as low as 3,000 to 4,000 rpm.

Over 90 percent of the torque is available from as low as 2,300 rpm. The V10 exhibits highly spontaneous throttle response and very refined running, and under load it also produces a sonorous, sportily gutsy acoustic backdrop, as befits a dynamic vehicle of Grand Touring calibre. The V10 is a far cry from a rough-diamond sports engine: for all its sporty character, this ten-cylinder engine is very low-vibration and exhibits plenty of refinement.

For Audi, lightweight design is a philosophy that has implications for every area of a vehicle. As in motor sport, the engineers developing the S6 fought to save every gram of weight possible. Thanks to its compact design and thinner walls, the V10 weighs just 220 kilograms. A dynamically balanced distribution of axle loads and impressive road behaviour are the result. For the same reason, the battery and the power management are housed in the luggage compartment.

The V10 lends the Audi S6 the road performance of a Grand Touring: the Audi S6 sprints from 0 to 100 km/h in 5.2 seconds, and the Avant estate-car version takes just one-tenth of a second longer.

The car effortlessly reaches its top speed of 250 km/h, the point at which the electronic governor smoothly cuts in, this performance being enhanced among other things by its low drag coefficient of cD 0.31.

The engine consumes a modest 13.4 litres of Super Plus fuel per 100 kilometres.

The Audi S6 weighs 1,910 kilograms (S6 Avant: 1,970 kg), including the dynamic, sure-footed quattro permanent four-wheel drive. Every horsepower consequently has to propel just 4.39 kilograms (S6 Avant: 4.53 kg) - the power-to-weight ratio of a top-notch sports car.

Drivetrain

The entire drivetrain of the Audi S6 has been designed from scratch. The engine's power on the S6 is translated into locomotion by a six-speed tiptronic as standard, which adapts to the driver's style by means of an intelligent feature. It performs this as a function of the momentary lateral and longitudinal acceleration forces and the amount of engine power that is currently being called up. The software program that controls the tiptronic electronically has been optimised to deliver more dynamic gear changes; the gear changes are noticeably swifter in the one-touch mode in particular.

The driver can call up the automatic transmission's "S" sport mode via the selector lever - the shift characteristics here are set for higher engine speeds.

And it is possible to change gear manually in both modes by means of the aluminium-look shift paddles that are located behind the steering-wheel rim and move in unison with the steering wheel itself (they are, in effect, mounted on the steering wheel). The selector lever has an aluminium look and - like the steering wheel - is trimmed in smooth leather.

The servotronic steering with its direct ratio makes a noticeable contribution to the agile handling of the S6.

Power and control

Typically for an Audi, the Audi S6 takes quattro permanent four-wheel drive as its basis. Its virtues are already widely acknowledged: superior traction in all driving conditions. More than a quarter of a century of expertise acquired in this domain by the Ingolstadt-based brand has led to the development of a new quattro generation with asymmetric/dynamic torque split - further evidence of Audi's guiding principle of "Vorsprung durch Technik".

A self-locking centre differential, installed longitudinally in the driveline, distributes power between the front and rear wheels, always according to the prevailing situation. The normal split is 40 percent to the front wheels and 60 percent to the rear - this slight bias in favour of the rear has been chosen to place even greater emphasis on the sporty, dynamic character of the Audi S6.

If the surface conditions change - for instance if they become wet or slippery, or if the car is driven onto a different type of road surface - this purely mechanical differential responds without any delay; depending on the requirements at any given moment, it can divert up to 85 percent of power to the rear wheels or as much as 65 percent to the front wheels. If a wheel on one axle spins (wheel slip), it is moreover brought under control by the Electronic Differential Lock EDL, which applies the brakes. This newly configured package of technical features guarantees a further increase in agility, particularly spontaneous turn-in properties and even greater driving stability.

The electronic stabilisation program ESP shuts down in two stages: when the ESP button is pressed once, only the ASR traction control system is deactivated; the ESP remains active, to stabilise the car if needed. The instrument cluster briefly displays "ASR off" and the ESP symbol remains permanently lit. It stays active in the Audi S6 until ASR is switched back on by pressing the ESP button a further time. On the new S6, ASR does not cut in automatically once a defined speed is exceeded (as is the case on the A6).

If the ESP button is pressed for longer than three seconds, all ESP functions are switched off. Only the electronic differential lock EDL and the anti-lock braking system ABS now remain active. Pressing the ESP button a further time switches all ESP functions on again.

As a result, the desired degree of electronic assistance can be determined by the driver via the ESP button. Without ASR traction control, the degree of stability can, within certain limits, be determined by the driver via the accelerator pedal. Drivers with sporting ambitions who may wish to probe the limits of handling can in addition completely deactivate the ESP functions with the second stage.

The drivetrain concept of the Audi S6 systematically and permanently ensures that the enormous forces generated by the V10 engine can genuinely provide efficient, minimal-loss propulsion, something that vehicles with one driven axle only rarely achieve. It is consequently able to develop and use high levels of power all the time.

Firmer and more spontaneous

The dynamic suspension layout of the Audi S6 is based on a technology that has already demonstrated its sports calibre in the most challenging of conditions: the refined four-link front suspension acknowledged as a typical Audi feature and the self-tracking trapezoidal-link rear suspension carried over from the A6. This combination gives the S6 one of the most complex and efficient rear suspension layouts currently available. In terms of its kinematic behaviour, this technical treat provides a foretaste of the out-and-out sporty, active characteristics of the Audi S6. The precise reduction of bump toe-in as a function of spring travel improves the car's directional stability, steering precision, and handling. The entire layout is designed in such a way as to produce a neutral response with a moderate tendency to understeer when the very high limits of handling are approached.

The chassis is constructed using a multi-material concept. The principal components of the chassis feature lightweight aluminium construction, resulting in decisively lower unsprung masses. The targeted use of sheet steel, on the other hand, achieves optimum rigidity wherever it is required. In selecting specific materials and manufacturing methods for each individual suspension link, Audi's engineers have been able to ensure that the chassis represents an optimum blend of low weight, high rigidity and maximum safety.

As a reflection of its explicitly sporty character, the suspension settings of the Audi S6 have been made firmer, even compared with the A6 sports suspension, and at the same time assure a high standard of comfort for long-distance driving. As the elastokinematics have likewise undergone comprehensive modifications, the Audi S6 is always noticeably more agile; driving stability and traction have moreover been further optimised specifically for the high performance standards of the Audi S6.

The Audi S6 is equipped ex works with 19-inch cast aluminium wheels of a 5-arm wing design. The wide tyres have the format 265/35 R19, a further feature differentiating them from the Audi A6.

An 18-inch brake system assures supreme braking performance and decelerates the car keenly even under high loads (this means that the size of the wheels fitted must be at least 18 inches). Its four large discs are ventilated, the discs on the front wheels measuring 385 millimetres in diameter and those at the rear measuring 330 mm. The front brake discs are 36 mm thick, the rear brake discs 22 mm. The brake calipers are painted black; the front calipers are adorned with a titanium grey supporting plate with an S-specific S6 emblem.

Supremely athletic presence

The models in Audi's S range have traditionally epitomised a consistent and refined form of sports appeal. This applies in equal measure to the Audi S6, which now dynamically hones the visual impact made by the A6. These models are renowned for their inherently light and elegant character - their very distinctive aesthetic appeal reflects their exceptional status as sports models in the luxury class.

The Audi S6 looks unmistakably even more supremely athletic out on the roads - but without even the slightest hint of aggression. The most striking differences compared with the A6 are to be found at the front end. The eye-catching single-frame grille displays the S6 emblem, and its vertical aluminium-look struts are of a double design by way of further differentiation. There is an air inlet beneath the grille. A spoiler lip at the front end of the car provides additional negative lift.

Another innovation in the front bumper is a pioneering development in terms of both road safety and style: the separate LED daytime running lights, each of which consists of five white light-emitting diodes and consumes only a minimal amount of energy. When these light strips are switched on, the effect is utterly distinctive: they make it incredibly easy to identify the Audi S6, and the low-down position of the daytime running lights gives the car a dynamically flat appearance.

To accommodate this concept, the front fog lights have been incorporated into the main headlights, the covers of which are tinted grey. Xenon plus headlights are provided as standard; Audi adaptive light, the dynamic cornering light, is optional. The rear light units incorporate LED brake lights as standard, and the S6 Avant in addition has LED-type tail lights.

The front wings are flared by 14 millimetres. The trim strips along the lower edge of the doors have likewise been made wider, to accentuate the "S" character; they are painted in the body colour. Other striking differentiating features are door sill trims bearing the S6 logo at all four doors, the rear spoiler integrated subtly into the luggage compartment lid (rather than merely added onto it) - the Audi S6 Avant has a roof spoiler - aluminium-look exterior mirrors, the V10 emblem at the front beneath the side turn indicators, and an S6 logo on the rear end. The vehicle's tail end also displays a colour-contrasting diffuser in the bumper, for turbulence-free air routing, and the four ellipsoidal tailpipes of the exhaust system, with its notably sporty acoustics.

The range of expressive body colours for the Audi S6 comprises three basic colours and eight other finishes. The solid paint finishes comprise the new colour Ibis White, Brilliant Red (exclusively for the S model) and Brilliant Black. The Audi S6 and S6 Avant are also available in the metallic colours Silver and, for the first time, Quartz Grey. The colours Aurora Blue, Phantom Black, Stratos Blue, Night Blue, Deep Green and Sprint Blue (another colour that is exclusive to the S model) have a pearlescent effect.

Interior - luxury and refinement in detail

In the same way as the body design, the interior of the new Audi S6 reflects a character of dynamic elegance and high quality - from the organically flowing driving area that surrounds the driver to the integrated MMI (Multi Media Interface) operating concept, which remains unequalled by any competitor thanks to its logical, intuitive operating principle.

The luxurious interior of the Audi S6 features specific highlights and distinguishing features. For instance, there is a new generation of sports seats. They have integral head restraints and pronounced lateral supports, and are upholstered in Alcantara/Leather; Silk Nappa leather is available as an option. The front seats are electrically adjustable in multiple directions as standard, and include a lumbar support. A multi-stage heating function for both front seats is included as standard. The rear seats are equipped with L-shaped head restraints affording a better view to the rear. ISOFIX mountings for installing child seats on the outer rear seats are standard.

The three-spoke multifunction leather sports steering wheel with the S logo is a typical example of the hand-crafted character that Audi so often achieves in its attention to detail: it is trimmed in smooth leather and displays a colour-contrasting double seam with an exclusive seam pattern. The reach and height of the steering wheel can be adjusted mechanically, and electric adjustment including an automatic entry and exit aid is available as an option. The shift paddles, which are mounted to the steering wheel (in other words, they move as it is turned), have an aluminium-look finish. The knob on the transmission selector lever is likewise finished in aluminium and trimmed with smooth leather; it can be supplied optionally in grey birch wood.

The trim inserts are in carbon fibre as standard. The material on the instrument panel represents a further innovation in the Audi S6: it correspondingly exhibits an anthracite-coloured metallic surface characteristic. Anthracite is also the predominant colour featured on the other sections of the instrument panel. The centre console, on the other hand, is in black.

The instrument needles are in white and its numbers use characteristic S-style italics; the dials are in dark grey. An S6 logo also adorns the dials of the rev counter.

The Driver Information System, which comes as standard, has an additional digital speedometer in the Audi S6. The driver receives information on a high-resolution 7-inch colour display, a standard feature of the MMI Multi Media Interface, which has a high performance yet is also straightforward and intuitive to use. There is a welcome screen customised specifically to the S6. The optional tyre pressure monitoring system displays the pressure and temperature of each tyre individually in the Audi S6. Compared with the A6, the MMI furthermore integrates the extended-specification radio system with double tuner (which searches for the same station on an alternative frequency in the background) and the DSP sound system with ten speakers and a CD changer for six audio CDs in the glove box.

The deluxe automatic air conditioning system plus with separate temperature distribution for the driver's and front passenger's sides, as well as air quality and humidity sensors, maintains a very high level of occupant comfort. The light and rain sensor and the cruise control system likewise play a part in this.

Innovative technology such as the MMI Multi Media Interface, battery energy management to ensure that the battery is always optimally charged, the electromechanical parking brake mounted on the centre console, with starting assist function, the double floor panel on the S6 Avant concealing a recess for muddy articles, and the light-emitting diodes in the brake and tail lights provide yet more evidence of Audi's proverbial "Vorsprung durch Technik".

Audi is likewise innovative when it comes to phoning in the car: the new optional telephone system will soon combine all the advantages of a built-in phone with those of the mobile phone preparation. The mobile phone is connected up to the vehicle's own GSM module by means of Bluetooth interface. This renders an adapter-type connection unnecessary and the driver can leave their mobile phone in their pocket while on the move.

Operation of the Bluetooth car phone is likewise via the MMI system in the Audi S6. A cordless handset in the centre armrest can also be supplied as an option.

Protection without compromises

quattro permanent four-wheel drive is one of the fundamental areas of expertise of the Ingolstadt brand. It gives Audi drivers decisively more active safety by assuring optimum traction in critical situations. The asymmetric/dynamic torque split that is possible on the new Audi S6 builds on this already significant advantage. The highly efficient brake system, too, makes a substantial contribution towards active safety.

Whereas the high standard of active safety of the new Audi S6 stems principally from its superior engine power, pioneering quattro drive and the complex ESP system, the sporty top model in the Audi executive range also boasts a full complement of passive safety systems. This model comes complete with a package of restraint systems that are perfectly matched to the highly rigid aluminium body, including two dual-stage full-size front airbags, side airbags for the front seats and large-area Audi sideguard curtain head airbags. Side airbags for the rear seats are available as an optional extra. All five three-point belts in the Audi S6 of course operate in conjunction with belt force limiters. There are belt tensioners for the front seats' restraint systems as standard. Audi backguard provides protection in the case of a rear-end impact.

The safety contribution of the daytime running lights on the Audi S6, which simultaneously represent an unmistakable design feature, should not be underestimated. The separate LED daytime running lights, each of which consists of five white light-emitting diodes and consumes only a minimal amount of energy - the individual diodes have a rating of just one watt - are a striking touch at the front of the S6. Furthermore, the flat light strips underneath the side air inlets underscore the flat, road-centred proportions of the Audi S6 and emphasise its status as a genuine sports car.

Individuality unlimited

Sporty components and high-tech systems also play the leading role in the list of optional extras. The radar-controlled adaptive cruise control, for instance, has a decisive advantage over conventional cruise control systems: this intelligent system continually measures the distance from the vehicle in front and correspondingly adjusts the car's own speed by manipulating the accelerator and brakes. Audi adaptive light provides a dynamic source of light when cornering, pivoting the headlights to cast their light into a bend.

Audi parking system is an acoustic rear-end parking aid, and its plus version supplies acoustic and visual feedback on clearance at both the front and rear, via the MMI display; finally, the advanced version activates a rear-view camera. The HomeLink garage door opener with programmable remote control opens garage doors and gates, but can also be used to control security and lighting systems.

There are numerous options in the infotainment area, such as a BOSE sound system with 5-channel surround reproduction, 13 speakers and 270 watts combined output, digital radio reception (DAB), analogue and digital TV reception, navigation system with DVD (dynamic route guidance with RDS-TMC), a speech dialogue system, and Bluetooth mobile phone provision and Bluetooth car phone.

There are optional inlays in matt brushed aluminium for the door trims and instrument panel which contribute to the individual look of the interior.

Alternatively, customers can order grey birch wood or mid-brown walnut for the door trim, instrument panel and centre console with an aluminium-look surround.

From the second half of the year, there will be the option of power-assisted closing, which helps by completely shutting doors that are not properly closed; it also incorporates electrically operated child safety catches for the rear doors.

The S6 Avant can be supplied on request with an automatically operated luggage compartment lid that is opened and closed electrically. The lid can be opened via a button on the car key, a button in the driver's door trim or the soft touch button on the lid itself. The luggage compartment lid, which includes lid closing assistance, is closed via the button on its inside; this button can also be used to program the desired opening angle.

18" winter wheels are available with various tyre sizes, as is a spare wheel with a full-spec tyre. The optional tyre pressure monitoring system monitors the tyre pressure and temperature of each the four wheels during the journey, including on factory-fitted winter wheels. The inflation pressure and temperature of the wheels can be displayed individually in the MMI.

Side airbags for the outer front seats complement the safety functions of the continuous Audi sideguard head airbag system and the side impact protection in the doors.

An electrically operated sliding/tilt roof of tinted glass with adjustable sun shield is available optionally, as is a solar sliding roof with integral solar cells which generate energy to run the ventilation blower even when the car is parked, in order to reduce the temperature inside the car. Roller sun blinds are available for the rear window (electrically operated for the saloon, mechanically for the Avant), and also for the rear door windows if desired.

The outer rear seats can be heated as an option. The Audi S6 also offers the optimised feature of an auxiliary heating/ventilation system for full climate control of the interior. The additional comfort of a pre-warmed interior means that it is no longer necessary to de-ice the windows in winter. In the summer, fresh-air circulation in the vehicle serves to reduce the temperature in the passenger compartment. The auxiliary heating and ventilation is activated either by way of the pre-select function on the on-board MMI "Climate Setup" menu or via remote control from a distance of up to 600 metres away.

On top of this, customers have a wide range of other optional extras to choose from.

A tradition of expertise: the S models

The S models' forte has traditionally been to blend outstandingly dynamic performance with extraordinary standards of comfort and attention to detail. They guarantee agile handling and nimble reflexes. But the suspension must never be so hard that your back starts to complain, nor the engine need be revved up so high that your ears are left ringing. This combination of advanced technology, dynamic performance and stylish sophistication in the S models traditionally appeals to younger customers of a more dynamic, sporty outlook who want to discover for themselves the absolute nature of the Audi brand.

The forefather of all Audi S models was the 1985 S1, the last and technically most advanced evolution model of the revolutionary rally competition car. 224 of its road-going version, the Sport quattro with Kevlar body and an output of over 300 bhp, were built. 1991 saw the first S model purely for use on public roads enter the showrooms - the Coupé S2, the designated successor to the "Ur-quattro" (original quattro).

In characteristic Audi style, the S2 was equipped with permanent four-wheel drive. It blended sportiness with refinement, the net effect of which was more than the sum total of these character traits. Inspired by the success of the S2, a self-contained family of S models grew over the years, from the S3 to the S4 and the S6, all the way up to the S8.

More or less in parallel with the S2, Audi brought out the first S6, though it was initially built as the S4 and was based on the Audi 100; it remained in production continuously from 1991 to 1997. This first S6 model - available as both a saloon and an Avant, and equipped originally with a 2.2-litre turbo engine, then also with a 4.2-litre V8 engine - was a bestseller with over 27,000 units sold worldwide.

The previous Audi S6 put in its first appearance at the 1999 Frankfurt Motor Show. It was notable among other things for a 4.2-litre V8 engine tuned up to 340 bhp, with five-valve technology, aluminium suspension and of course quattro permanent four-wheel drive, and remained in production until the end of 2004.

Sales of all S models together up to the present day amount to some 150,000 units.

Like its predecessors, the new Audi S6 has been developed for people wishing to express their individuality through the car they drive. Many of these are businesspeople or successful freelancers who have opted for a prestigious sports car with high suitability for everyday use and which is intended to encapsulate their personal success and communicate their outlook as top performers.

The most important sales markets for the Audi S6 are Germany, the USA and Switzerland.