The luxury-class sports
model
Engine
Drivetrain
Chassis
Design
Interior
Safety
Equipment
The equipment, data and prices stated here refer to the model range
offered for sale in Germany. Subject to amendment; errors and omissions
excepted.
The luxury-class sports model
Audi S8
Distinct sports appeal and supreme comfort – these are the two defining
characteristics of the Audi A8. At the time of its market launch three years
ago, this large saloon shot straight to the top of the luxury segment thanks to
its dynamic qualities. The brand with the four-ring emblem is now unveiling a
sporty top model of the very highest calibre in the luxury segment: the new Audi
S8. It will be appearing on the market in the mid of 2006.
The Audi S8 is equipped with a new V10 engine that capitalises on the
expertise of the super sports car Lamborghini Gallardo. The 10-cylinder power
unit develops 450 bhp of power and 540 Nm of torque from a swept volume of 5.2
litres. The torque value is achieved at as low an engine speed as 3,500 rpm. As
on the Le Mans winning R8, the most successful racing car in the world, FSI
petrol direct injection assures superior power output in the Audi S8. This
luxury saloon sprints from 0 to 100 km/h in 5.1 seconds, and is electronically
governed at 250 km/h.
The driveline and chassis of the S8 have been modified to reflect the
engine's power. A quattro drivetrain of the latest generation with
asymmetric/dynamic torque distribution diverts the engine's power to all four
wheels. The firmer settings of the adaptive air suspension sport and
modifications to the steering ensure that the power and dynamism of the
drivetrain are translated with precision into locomotion.
The design of the new S8 completes the picture – the sporty top model also
has the looks of the most athletic luxury saloon car. There is an atmosphere of
luxurious elegance inside the car. Its lavish equipment lends the Audi S8 a
pre-eminent status within the competitive field.
Engine
New V10 with FSI technology adopted from the world of motor racing
In outfitting the S8 with the V10, Audi is introducing an engine technology
that has long been demonstrating its performance potential in the world of
Formula 1 racing. The Italian super sports car brand Lamborghini, a subsidiary
of Audi, likewise regards the ten-cylinder engine as synonymous with dynamic
power. This engine concept has a much more sporty emphasis than a comparable
twelve-cylinder power unit. Ten-cylinder engines are more compact and lighter;
thanks to the smaller number of components, they have lower moving masses and
less internal friction.
The 450 bhp V10 is the second generation of Audi V-engines, all with a
90-degree included angle and a spacing of 90 millimetres between cylinder
centres. Key areas of the Audi version have been reengineered compared with the
engine in the Lamborghini Gallardo. The bore has been increased from 82.5 to
84.5 mm; the stroke is 92.8 mm and the displacement 5204 cm3. A so-called
bedplate structure – an intermediate frame – reinforces the extremely compact
crankcase, which is made from cast aluminium.
With its crankpin offset of 18 degrees, the V10 fires at the ideal spacing of
72 degrees crankshaft angle. A balancing shaft located within the "vee"
eliminates the so-called free inertial forces of the first degree and also
contributes towards the engine's notable refinement. All four camshafts can be
adjusted continuously by 42 degrees crankshaft angle, depending on load and
engine speed, to optimise filling of the combustion chambers and thus enhance
the power output. They are driven by no-maintenance chains and actuate the 40
valves via roller cam followers.
The V10 in the new Audi S8 uses FSI petrol direct injection. This permits a
high compression ratio of 12.5:1 and a correspondingly more effective combustion
process based on a lambda value of 1. The common rail injection system delivers
the fuel directly to the combustion chambers in precisely metered amounts, at a
pressure of up to 100 bar.
The two-stage magnesium variable intake manifold incorporates electronically
controlled tumble flaps that induce a swirling movement in the air drawn in.
Four close-coupled main catalytic converters take charge of exhaust emission
control for the V10 of the Audi S8. FSI technology has impressively demonstrated
its potential in motor sport – the R8 racing car equipped with it participated
in the Le Mans 24 Hours on five occasions for Audi, winning the race on four of
those occasions.
The powerful ten-cylinder engine is designed for impressive torque as well as
engine power. It generates 450 bhp at 7,000 rpm, but musters up 540 Nm of torque
at just 3,500 rpm. 90 percent of the torque is available from as low as 2,300
rpm. The V10 exhibits spontaneous throttle response and very refined running,
and under load it also produces sonorous acoustics, as befits a dynamic car.
The V10 imparts the luxury saloon with the road performance of a high-calibre
sports car. The Audi S8 races from 0 to 100 km/h in 5.1 seconds. The speed is
not governed electronically until the needle reaches 250 km/h. The engine shows
a distinctly modest thirst, needing only 13.9 litres of fuel per 100 kilometres
– a figure achieved partly thanks to the consistent use of lightweight design,
which clearly sets the A8 range apart from its competitors. With its innovative
aluminium body, the Audi Space Frame ASF, the S8 weighs just 1940 kilograms,
including the dynamic, sure-footed quattro drive. On the new Audi S8, every
horsepower has to propel just 4.31 kilograms – the power-to-weight ratio of a
sports car.
Drivetrain
Even more dynamism
Typically for an Audi, the new S8 likewise focuses on quattro permanent
four-wheel drive. As a result it produces superior traction in all surface
conditions. 25 years of expertise acquired in this domain by the brand with the
four-ring emblem have led to the development of a new quattro generation with
asymmetric/dynamic torque distribution – further evidence of Audi's philosophy
of "Vorsprung durch Technik".
A centre differential, installed longitudinally in the driveline, distributes
power between the front and rear wheels according to the prevailing situation.
Normally, 40 percent is routed to the front wheels and 60 percent to the rear,
this slight emphasis on the rear underlining the dynamic character of the Audi
S8. If the surface conditions change, the purely mechanical differential
responds without any delay; it can divert up to 85 percent of power to the rear
wheels, and as much as 65 percent to the front wheels. If a wheel on one axle
spins, it moreover overrides the Electronic Differential Lock EDL by applying
the brakes.
The new S8 is equipped with six-speed tiptronic as standard. In keeping with
the character of this saloon model, the final ratio of the automatic
transmission is lower than on the A8 – the saloon is still capable of forceful
acceleration even in sixth gear. The electronic transmission control is
optimised to change gear more dynamically. The driver can call up the
transmission's Sport mode via the selector lever – it still performs upshifts
even at relatively high engine speeds. It is in addition possible to change gear
manually with the shift paddles located behind the steering wheel.
For Audi, lightweight design is a philosophy that has implications for every
area of a vehicle. The V10 in the Audi S8 weighs in at a mere 220 kilograms, in
other words 20 kg less than an equivalent competitor engine. Good axle load
distribution and impressive road behaviour are the result. For the same reason,
the batteries and the energy management are housed in the luggage compartment.
Chassis
Built for serene speed
The basic version of the Audi A8, adaptive air suspension, already possesses
distinctly sporty attributes thanks to its elaborate layout. The control arms
are made from aluminium; the front suspension consists of a four-link structure,
and there is self-tracking trapezoidal-link rear suspension. Various details of
this layout were revised on the S8.
The basis is "adaptive air suspension sport", the sports suspension layout
that is available for the A8 as an option. On the S8, the characteristics of the
air springs and the shock absorbers integrated into the air-spring bellows have
been made somewhat firmer. With a further reduction in rolling and pitching
movements, the sporty top model behaves with even greater agility and
manoeuvrability, but is as stable and safe as ever. The elastokinematics of the
rubber mounts in the axles have likewise been modified in keeping with the
character of the S8. The variable steering ratio is roughly ten percent more
direct, for even more spontaneous handling.
Drawing information from seven special sensors and a number of other
parameters, the damping responds adaptively to the prevailing requirements in a
fraction of a second. Its control system features four driving modes –
automatic, comfort, dynamic and lift – which the driver can call up via the
terminal of the MMI operating system. The body's ride height is as envisaged in
conjunction with adaptive air suspension sport, which is already 20 mm lower
than standard. On the S8, ground clearance is varied in three stages between 125
mm in the comfort mode and 95 mm at constant high motorway speeds.
The Audi S8 is equipped ex works with S-design cast alloy wheels. Their
dimension is 9J x 20, and the wide tyres are size 265/35. An 18-inch brake
system assures a superlative braking performance. It features four large-size
ventilated brake discs. The brake calipers are painted black, and adorned with a
titanium grey S8 badge at the front. The discs on the front wheels measure 385
millimetres in diameter, and 335 mm at the rear.
The optional ceramic brakes that also became available for the
twelve-cylinder A8 in summer 2005 are a further special feature of the S8. They
are made from a composite material comprising high-strength carbon fibres
embedded in hard, frictionally resistant silicon carbide. The ceramic discs
offer significant advantages compared with conventional steel discs. They are
about half the weight, are largely insusceptible to heat fading and corrosion,
and achieve an operating distance of up to 300,000 kilometres – four times that
of steel discs. Optically, the high-tech brake system can be identified by the
special perforation on the large-size discs and the anthracite-coloured calipers
with the "Audi ceramic" lettering.
Design
Discreet sports style
The models in Audi's S range have always epitomised refined sports appeal.
The same applies to the S8 – it lends the design of the A8 a dynamic edge. This
representative saloon is already inherently light and elegant in character – its
aesthetic appeal reflects its exceptional position as a sports model in the
luxury class.
The S8, too, is supremely athletic yet never aggressive in outlook. The most
striking differences are to be found at its front end. The eye-catching
single-frame grille displaying the S8 emblem is in platinum grey, and its
vertical struts have a chrome finish. Beneath the grille, there are three low
air inlets cut into the front apron. The two large air inlets beneath the
headlights are filled with honeycomb grilles.
Down the sides, in addition to the 20-inch wheels and the special brakes,
three details hint at the potential of the V10 engine: emblems on the wheel
arches, door handles with aluminium strips and the aluminium-look exterior
mirror housings. At the rear, the S8 emblem, a spoiler integrated into the
luggage compartment lid, a subtle light edge in the apron and an exhaust system
with four ellipsoidal tailpipes complete the range of optical modifications. The
S8 is the only model in the A8 range to be available in the exclusive colour
Daytona Grey, pearl effect.
Interior
Attention to detail
In common with the exterior, the interior design of the Audi A8 reflects a
character of dynamic elegance and high quality – from the supple flow of the
driving area to the MMI user interface (Multi Media Interface), which remains
unequalled by any competitor thanks to its logical, intuitive operating
principle.
The S8 adds various specific accents to this luxurious interior. This is the
first time that bi-colour seats with seams in a contrasting colour have been
used as standard; their four colour combinations emphasise the air of luxurious
sports appeal. The colours for the seat centre sections differ from those for
the side sections and head restraints. The headlining is additionally available
in the S models' signature colour silver.
Further details of the interior distinguish the sporty top model from the A8.
The door sill trims are adorned with S8 emblems, and the inlays are in brushed
aluminium or alternatively carbon fibre. The three-spoke leather multifunction
sports steering wheel with the S emblem features colour-contrasting seams and
aluminium-look shift paddles. Leather and aluminium are used on the selector
lever knob. The needles on the instrument dials are in white, their scales in
light grey and their values in the characteristic S italic script.
Safety
No compromises
quattro drive is one of the core areas of expertise of the brand with the
four-ring emblem. It gives Audi drivers decisively more safety by always
assuring optimum traction. The asymmetric/dynamic torque split that is possible
on the new Audi S8 builds on this already significant advantage. The
high-performance brake system, too, makes a substantial contribution towards
active safety. The S8 is equipped with a dynamic stability system that can be
deactivated if required. Its control strategy is tailored specifically to the
dynamics of the S8.
In common with all other Audi A8 models, the S8 sporty top model comes
complete with a package of restraint systems that are perfectly matched to the
highly rigid aluminium body. The package includes two front airbags, four side
airbags and large-area sideguard head airbags. All five three-point belts in the
Audi S8 are fitted with belt tensioners. Active head restraints for the front
seats reduce the risk of whiplash injuries in the event of a rear-end collision.
The innovative lighting technology adaptive light with LED daytime running
lights is standard equipment on every Audi S8. Here, the xenon plus headlights
are equipped with static turning lights and dynamic cornering lights. The
separate LED daytime running lights, each of which consists of five white
light-emitting diodes and consumes only a minimal amount of energy, can be
considered a pioneering invention.
Equipment
Luxury with new accents
The Audi A8 is already a luxuriously equipped saloon. It features for
instance deluxe automatic air conditioning, the MMI operating system, the Driver
Information System, the electromechanical parking brake complete with starting
assist function, air suspension, the exclusive audio system and the electrically
adjustable front seats.
The Audi S8 extends this package with a whole array of other standard
features. In addition to adaptive light technology, the special 20-inch wheels
and the 18 inch brake system, it incorporates further luxury features in the
version for the German market: advanced key, the keyless access and
authorisation system including starter button for the V10, sound-insulating
double glazing for the windows, heated front and rear seats, a navigation system
with DVD drive and a surround audio system with CD changer. The door armrest and
the centre console in the S8 are upholstered in leather, together with the
seats. The sports seats are equipped with lumbar supports and a memory function.
One particular highlight that is available as an option is the Advanced Sound
System from Bang & Olufsen. The fully digital system from the Danish
high-end manufacturer integrates 14 speakers, each energised by its own output
stage. The output stages are grouped together in two amplifiers, which supply an
output of 1100 Watts if required. The front tweeters use what is known as
Acoustic Lens Technology, and act as perfect punctiform sound sources. This
sound system represents the state of the art in audio reproduction adding
special allure to the sporty, deluxe equipment of the Audi S8.
|
