Audi has stretched the bounds of luxury saloon comfort even further in the new long wheel base version of its flagship A8 saloon, which incorporates an additional 130mm of wheelbase and body length, the latter concentrated at the rear to provide even more exceptional passenger accommodation. Making its world public debut at the Beijing Motor Show (April 27-May 2), and due to open for UK order in late July priced from around £58,000, the new Audi A8 L will also be further refined by an extensively reworked version of the twelve cylinder W12 petrol engine offering further improved power and efficiency.
Audi A8 LWB at a glance
- Long wheelbase versions of Audi luxury saloon open for order in late July for first deliveries in December 2010 – OTR prices expected to start from around £58,000
- 3.0-litre TDI (250PS), 4.2-litre TDI (350PS), 4.2-litre FSI (372PS) and 6.3-litre W12 FSI (500PS) power
- 130mm increase in wheelbase length, body length extended by the same amount and all incorporated at the rear to maximise passenger comfort
- Additional equipment includes heated outer rear seats, sunroof, deluxe four-zone climate control and electric rear and side window blinds
The 130mm increase takes the length of the new A8 L to 5,267 millimeters, and the wheelbase has grown by the same amount to 3,122mm. Lightweight aluminium employed for all elements bar the safety boosting high strength steel B pillars ensures that the extended Audi Space Frame (ASF) body, like its standard wheelbase counterpart, weighs around 40 per cent less than an all-steel equivalent.
Power will come courtesy of four engines – the 3.0-litre TDI (250PS), the 4.2-litre TDI (350PS), the 4.2-litre FSI (372PS) and, exclusively for the long wheelbase model, the W12, which in its latest application has been bored out from 6.0-litres to 6.3-litres, and incorporates FSI direct petrol injection in the interest of optimum economy and emissions control. Maximum power has increased by 50PS over the previous version to 500PS, and the 45Nm higher torque peak of 625 Nm arrives at 3,250 rpm.
12 per cent economy improvement
As a result, the A8 L W12 can cruise serenely to 62mph in just 4.9 seconds, and continue to a seemingly effortless governed top speed of 155mph. And with the help of FSI technology, fuel economy belies these figures, with up to 23.5mpg achievable according to the combined cycle test – a 12 per cent improvement over the outgoing model which results in CO2 output of 278g/km.
Thanks to its cylinder arrangement, which forms the ‘W’ shape that gives this model its name, the W12 engine is exceptionally compact at just over 50cm in length and 70cm in both width and height, and its overall weight of 247kg is also impressively low helped by high aluminium content.
The two camshafts within each of the engine’s aluminium cylinder heads operate 48 valves by way of low-friction roller cam followers, and are themselves driven by chains from an intermediate shaft. The cylinder heads themselves have been extensively modified to enable FSI technology to be incorporated, and as a result fuel is injected into the combustion chambers at a pressure of up to 130 bar, giving a high 11.8:1 compression ratio that boosts power output and efficiency.
New efficiency measures
The crankshaft and timing chains have also been reworked to reduce friction, and a recuperation system recovers energy that would otherwise be lost when the car is braked. An innovative thermal management system also shuts down the coolant circuit for a time after the cold engine has been started. This warms up the engine oil more rapidly and shortens the operating period in which friction is still high.
Efficiency is also boosted further still by the new eight-speed tiptronic automatic transmission, which shifts smoothly and quickly, with the individual gears closely spaced but with a generous overall spread from low to high. Gear shifts are performed electronically (“shift by wire”) via the yacht-style selector lever or steering wheel paddles.
The centre differential, the main component in the quattro permanent all-wheel drive train, allots up to 60 per cent of the torque flow to the rear axle and 40 per cent to the front in regular driving conditions. If driving conditions warrant it, up to 60 per cent of the torque can be sent to the front, or 80 per cent to the rear. An optional sport differential can split this torque input actively between the left and right rear wheels. Its responses can be fine-tuned, along with throttle response, steering assistance and transmission shift points, at the touch of a button via the built-in Audi drive select adaptive dynamics system.
Thanks to its advanced adaptive air springs, aluminium-intensive suspension and latest generation quattro all-wheel-drive, the long-wheelbase Audi A8 manages to combine the polished ride refinement expected of a luxury car with handling poise and agility that would normally characterise performance saloons from one or two classes below.
130mm more space to recline
The full extra length of the A8 L benefits rear-seat passengers, who are able to enter even more easily through wider doors which, in the W12 version, feature power assisted closure. Rear passenger comfort is also further improved by standard seat heating, an upgraded climate control system which enables precise temperature modulation in the two rear ‘zones’ and electrically operated rear window and side window blinds. In the W12, comfort is taken to even greater extremes by replacing the standard rear seat arrangement with two individual sculpted rear seats which can be heated and ventilated and feature fore/aft adjustable bases and angle adjustable backrests.
Travel is made even more effortless and pleasurable in the A8 L W12 by double glazing, even more extensive use of Fine Nappa leather taking in everything from the glove compartment lid to the area surrounding the MMI controls, a CD changer playable through a BOSE audio system and a sophisticated Bluetooth mobile phone connection system that enables occupants to access selected content from the internet. All-LED headlights, 19-inch 15-spoke alloy wheels and a powered sunroof are also features that set the top flight model apart from other A8 L versions.
As expected of an Audi, the A8 L also has pioneering innovation on board: the standard MMI navigation plus system, which operates with the aid of a high-capacity hard disk, has a touch-sensitive control panel known as MMI touch. The driver inputs his or her navigation destination or a telephone number simply by writing the letters or numerals on the pad with a finger. Acoustic feedback makes this possible without taking one’s eyes of the road.
The navigation system cooperates with the assistance and safety systems in an innovative way. It registers the topography of the road in advance and makes this data available to the control units for the automatic transmission, headlights and adaptive cruise control with Stop & Go function. Thanks to their advanced intelligence, these systems can identify complex scenarios and offer the driver support in good time.
The Audi side assist system, which helps the driver to change lanes, and Audi lane assist which detects any departure from the chosen lane, also have new and additional performance features.
The night view assistant uses a thermal imaging camera to identify pedestrians on the road ahead of the car. If it considers the situation to be potentially dangerous, the image of the person on the road is shown in red and a warning signal is heard. The Audi pre sense safety system is also closely linked to the assistance systems. It is available in several stages: the full version brakes the car automatically in order to minimise the consequences of a nose-to-tail collision.