Engine and drive train
The A8 has an advanced V8 engine with spark ignition and a three-stage variable intake manifold. This five-valve per cylinder double overhead camshaft engine displaces 4 172 cc and produces maximum power of 246 kW at 6 500 r/min and 430 Nm of torque at 3 500 r/min.
The car uses Audi Space Frame (ASF) technology which combines a body of aluminium panels mounted on a high-tensile structure of extrusions and castings.
Over the last 10 years, Audi has produced in excess of 200 000 cars with an aluminium construction and for the A8, this construction method has been refined even further.
The static torsional rigidity has been increased by 60%t and ensures a major enhancement in vibrational comfort, safety and dynamic handling potential.
It weighs only half that of a steel body with the same rigidity.
As a result, the new A8 has the lightest body shell in the entire top-end luxury segment of the market, with an unladen weight of 1 780 kg.
When the advantages of ASF III are combined with the quattro permanent all-wheel drive system, the benefits to the driver are added agility and driver enjoyment.
With any vehicle, the engine, brakes and cornering impose longitudinal and lateral forces on the wheels and tyres. When these forces become too great, the tyres lose grip.
The quattro principle increases tyre grip by distributing the drive force to all four wheels. Each wheel now has more capacity to absorb lateral forces which, in turn, means better control and higher levels of active safety.
The new Audi A8 has a further developed aluminium chassis with four-link front axle and a self-stabilising trapezoidal-link rear axle. The brakes and steering system with variable ratio and servotronic are a new design.
The adaptive air suspension reduces body movements with its continuously adjusting damping and thus optimises road holding and comfort.
The data from four sensors on the axles and three acceleration sensors on the body is evaluated in the adaptive air suspension's central control unit.
This computer prompts the adjustment of the individual shock absorbers in a matter of milliseconds, based on the driving situation identified, thereby always assuring optimum driving dynamics and ride comfort.
The driver can choose between four predefined settings, for a suspension characteristic ranging from overtly sporty to ultra-comfortable.
In the automatic mode, the body is at the standard height when stationary and at medium speed, with 120 millimetres of ground clearance.
If the new A8 is driven at more than 120 km/h for over 30 seconds, the body is lowered by 25 millimetres.
In the reverse order, the body is raised if the vehicle is driven more slowly than 70 km/h for more than two minutes or as soon as it drops below a speed of 35 km/h.
The dynamic mode lowers the vehicle by 20 millimetres to a ground clearance of 100 millimetres even before it sets off; its centre of gravity is lower and the air suspension operates with firmer springs and a harder damping characteristic. The suspension tuning is particularly agile as a result.
Once again the same threshold speeds apply for automatic changes in ride height: if the car is driven faster than 120 km/h for more than 30 seconds, the body is lowered by a further 5 millimetres.
And the body is raised again if the vehicle is driven more slowly than 70 km/h for more than two minutes or as soon as it falls below a speed of 35 km/h.
The comfort mode enables the car to glide extra-smoothly over all kinds of surface bumps because the system increases damping forces less frequently at lower speeds. The automatic lowering at motorway speeds is suppressed in order to obtain maximum compression travel.
The lift mode can be activated in the speed range below 80 km/h as required. It raises ground clearance constantly by 25 millimetres and offers the balanced damping characteristics of the automatic mode.
The A8 has rack-and-pinion steering with variable ratio and speed-dependent power assistance, servotronic, as standard equipment.
It is fitted with a newly developed high-performance brake system that is much larger than on the predecessor model, with aluminium floating-calliper brakes front and rear - 360 mm at the front and 310 mm discs at the rear.
The brake system is supported by the Electronic Stabilisation Programme (ESP 5.7) with ABS, ASR traction control, Electronic Brake-force Distribution (EBD), Electronic Differential Lock (EDL) and hydraulic brake assist.
The electromechanical parking brake is also making its debut on the Audi A8. It brings clear functional benefits as well as performing all the tasks of a conventional handbrake.
The system, operated via a pull/push control on the centre console, automatically ensures the necessary parking brake application force.
The operating concept is deliberately based on what most drivers would consider the usual operating principle for conventional systems: a quick pull of the switch applies the brake; if the driver pushes it down - while the brake pedal is depressed - the system is released.
An integrated starting assist function facilitates smooth driving off on hills without the driver having to manually disengage the brake.
The system calculates the moment and rate at which the parking brake is to be released, on the basis of data such as the transmission speed selected, the accelerator pedal position, the engine speed and the angle of incline.
As soon as there is sufficient torque to move the vehicle forwards, the electronics automatically release the parking brake.
The A8 4.2 quattro has the sporty 5-spoke 8.5J x 18-inch alloy wheels as standard, with 255/45 R18 tyres. Options are 8.5Jx19-inch, with 255/40 R19 tyres.
A full-size spare wheel as standard.
A permanent tyre pressure monitoring system is also available as an option - it monitors the tyre pressure and temperature of each individual wheel and informs the driver optically and acoustically via the display in the instrument cluster if there is a loss of pressure and indicates which wheel is affected.
A summary of all the momentary inflation pressures and temperatures of all four wheels can in addition be called up via the MMI terminal.
Correct values appear in green lettering, red values indicate that the pressure should be corrected without delay.
The MMI system in the first instance comprises the control panel (MMI terminal) in the centre console with a control button that can be turned and pressed and four control keys grouped around it.
On either side of the terminal - apart from the Return key for exiting the menu level - there are a total of eight function keys with which the user can call up the principal main menus directly.
The second central component of the MMI, an 18 cm mm colour monitor, is positioned above the centre console in the dashboard and therefore at an optimum angle of view for the driver.
The highlight - the basic geometry of the monitor display corresponds in detail to the layout of the control keys and button in the MMI terminal.
In other words, the driver uses the top left control key to select the function displayed in the top left corner of the screen. There is thus an intuitive link between visual perception and hand movements.
The driver only needs to remember four basic rules for operating the MMI:
The main functions of the system - entertainment, communication, information and control of vehicle systems - are accessed by the eight permanently assigned function keys.
Within these function menus, the driver activates the required functions by turning/pressing the control button.
The control keys, to which different functions are assigned for each menu, provide access to further functions in the menu. These can be read off in the corners of the display which also vary depending on the menu selected.
The user simply presses the Return key to skip back to the next-higher menu level.
The more frequently a function is used in the car, the higher up the menu structure it is placed, thus making it quicker and easier to access.
The new A8 offers numerous innovative electronics technologies, some of which are available for the very first time in an Audi.
These include, to name just a few examples, the advanced key access and authorisation system, one-touch memory personalisation and the radar-assisted distance control system known as adaptive cruise control (not available at launch).
Inside the car the standard equipment is extensive, but there is an extensive options
The buyer can choose from several interior and leather combinations; comfort seats with massage function, heating and ventilation; double glazing for the side windows with break-in protection; to name but a few.
Fingerprint recognition caters for the specific needs and requirements of the driver so that vehicle functions and systems can be tailored personally.
Since the settings are saved to a particular individual's fingerprint, there can be no confusion once that individual has identified him or herself to the vehicle.
This means that the right settings for the right person are available by merely touching the fingerprint sensor. Any necessary adjustments or settings (to the sound system, seats or air-conditioning system, for instance) is done automatically once the driver is recognised.
Available as an option, the Fingerprint Keyless Entry System brings this new technology to local buyers as well.
The workings of the system are complex and utilise a sensor/reader integrated into the start button of the new Audi A8 located next to the gear lever.
If the driver's fingerprint has been stored in the car system, all he or she need do is touch the sensor for personal settings to be called up.
When the start button is actuated by the finger, a sensor comprising of 65 000 electrodes scans the fingerprint. From this a digitised grey scale image of the fingerprint is produced.
Once the driver and car are "paired" the process of storing individual settings and system requirements can begin through the One-touch memory system.
The driver can choose the level of air-conditioning in the vehicle, his or her choice of radio station or CD, seat adjustment, air suspension settings etc.
Starting the vehicle, though, remains dependent on whether or not the actual key is with the vehicle at all times.
In addition, the One-touch memory system also works as a keyless entry system. To gain access to the vehicle, all the driver needs to do is have the key in his or her pocket and then touch the door handle.
As an option, the Audi A8 can be equipped with a sophisticated voice recognition system to allow for true hands free operation of key vehicle functions.
By simply "speaking" to the vehicle, the driver can call up telephone numbers, input navigation commands and select entertainment source, to name but a few.
This new generation voice recognition system has been developed to allow the driver to speak more naturally, instead of slowly inputting voice commands.
The system can also understand a wider variety of speech tones and commands, making it simpler to use.
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