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Saturday, February 2, 2008

Audi A6 allroad quattro


Despite its imposing dimensions, the new Audi A6 allroad quattro is nevertheless significantly smaller than the Audi Q7 performance SUV. It measures 4,934 millimetres long, 1,862 mm wide and, depending on the setting of the standard adaptive air suspension, between 1,459 and 1,519 mm high.

Compared with its predecessor, the new model is noticeably larger, with an extra 124 mm of length and 10 mm of width. The new A6 allroad quattro is available exclusively in Avant guise.

Torsional rigidity has been boosted by over 34 percent – an increase that bears clear testimony to the diligent work carried out by the Audi engineers. This extra strength makes its presence felt in terms of both superior vibration comfort and driving dynamics. The minimised vibration amplitudes are one of the key factors behind the excellent interior acoustics of the new A6 allroad quattro.

Lightweight construction: the fine art of sheet metal engineering

The systematic use of high-strength and ultra-high-strength sheet steel has made it possible to reinforce the structural components that are essential for ensuring a high level of stability. The inclusion of lightweight aluminium components such as panels and extruded profiles, on the other hand, has helped to save a considerable amount of weight. The A6 allroad quattro 3.2 FSI, for example, tips the scales at just 1,760 kilograms.

As on the predecessor, sheet aluminium proved to be the ideal material for the bonnet and front wings. Aluminium can also be used, however, on structural components that are subject to only moderate loads, such as the front panel of the radiator tank. The extruded aluminium profiles that have been added to the side sills help to reinforce the passenger cell.

The front roof frame has a hybrid structure, made from a combination of steel and plastic.

Tailored blanks, which are plates with varying wall thickness, or the closely related tailored rolled blanks are used at points subject to particularly high loads, such as the suspension strut cross-members or the front longitudinal members.

The various components are connected to one another using a range of different techniques: apart from conventional spot welding, rivets, spot welding combined with bonding, laser welding and soldering as well as MIG welding help to produce a lasting, solid connection. Each technology corresponds to the exact requirements at the point it is used.

The backbone of a sound safety concept: a rigid passenger cell

One of Audi's fundamental objectives in developing every model is to make the passenger cell extremely rigid. After all, this is the basic structure serving as the foundation for all of the car's restraint systems and their protective effect.

One of the most important aspects to consider when designing this cell is behaviour in a frontal impact, as this is by far the most common type of impact in accident statistics.

This presents the body development engineers with two main tasks: first, to convert kinetic energy into deformation energy absorbed by body components and secondly, to ensure that this energy does not even reach the passenger cell, which must be made as robust as possible.

In a frontal crash, intelligent up-front sensors behind the radiator grille interact with other sensors and control units, before alerting the central control unit that the car has been involved in an impact within just a few thousandths of a second. The belt tensioners are then ignited just a few milliseconds later in order to minimise any possible belt slack. Once the loads acting on the belts have reached a certain limit, a belt force limiter feeds out additional belt length, allowing the occupants to "fall" into the airbag once it has inflated.

The full-size front airbags are activated in two stages: in the first stage – activated in low-speed impacts – the forces acting on the occupants are kept at a low level.

At higher speeds, the second stage is triggered in order to utilise the full safety potential of the front airbags.

The particular position chosen for numerous elements, such as the air conditioning, control units, the ignition lock and key, is also an integral part of the car's safety concept. All hard components have been moved away from critical impact areas where they might harm the occupants; other areas such as the footwells are cushioned by extensive padding.

The safety steering column comes with a double telescoping function, in other words it is – like the pedals – isolated from any intrusions from the front end of the car. A force limiter at the steering column mounting additionally ensures that the steering column will yield in response to impact with the driver's chest, causing the steering wheel to move down to prevent injury.

In a frontal crash at low speed, there is no need for the airbags to be triggered. In such cases, all of the energy is absorbed by the bumper system, avoiding the need for expensive repairs to the welded body structure behind. Thanks to the precise deformation of the bumper, even the wings remain unharmed in a head-on collision at 15 km/h. Clearly, these are features that insurance companies welcome and duly reward with a particularly favourable insurance premium.

Rapid response units: protection in a side impact too

Unlike the front end of the car, there is only minimal deformation travel available at the side for absorbing energy. Only a particularly high degree of strength in this area can protect the occupants: this is precisely why the flanks of the new Audi A6 allroad quattro have a high-strength structure made primarily from dual-phase steels which offer outstanding rigidity and protection against excessive loads.

In the side sill, an extruded aluminium profile ensures effective absorption of energy. Within the doors, tailored blank inner panels combine with reinforcements at lower window edge and sill level plus an aluminium impact beam to offer substantial resistance to deformation.

Several beams arranged perpendicular to the direction of travel likewise serve to stabilise the passenger cell, while two high-strength steel pipes also installed laterally in the front seats help to keep the occupants' survival space intact. High-strength reinforcements extending far into the roof area serve to protect the occupants if the vehicle rolls over.

In a collision from the side, the occupants are protected by side airbags fitted as standard at the front (optionally available at the rear) and the head airbag system known as sideguard. The latter covers almost the entire side window area. Hybrid gas generators inflate the airbags in an instant and the pressure is furthermore maintained for a longer period, ensuring that there are still sufficient safety reserves to protect the occupants in the event of a second, subsequent collision.

The new Audi A6 allroad quattro is also extremely well protected against the consequences of collisions from the rear. The cell is built to withstand an impact against a deformable barrier with 70 percent overlap up to a speed of 80 km/h. In such a collision, the fuel tank also remains outside the actual deformation area courtesy of the rear structure of the car consisting of powerfully proportioned members which absorb all of the impact energy.

Aerodynamics: deft design makes up for larger frontal area

More interior space, a wider track: the new Audi A6 allroad quattro is significantly larger than its predecessor. Since the extra width also means a larger frontal area, the aerodynamics engineers were faced with the task of compensating for this fundamental drawback by adopting a particularly elaborate design for the car's outer skin. Once again, Audi showed itself to be fully up to this task, as testified by the drag coefficient (Cd) of just 0.33 for the new Audi A6 allroad quattro 3.2 FSI. The product of drag coefficient and frontal area is slightly improved in the new model.

One feature that is particularly important in terms of aerodynamics is the underbody panelling. At the front end, the underride protector together with the encapsulation of the engine compartment and transmission ensures a swirl-free flow of air to the central floor area, while wheel spoilers reduce flow losses around the front wheels.

Large cover panels conduct the flow of air along the transmission tunnel all the way back to the rear wheels where it is channelled by the rear underride protector and directed behind the vehicle.

Minimising the uplift at the rear axle is of decisive importance for vehicle handling and stability. The aerodynamic engineers at Audi have developed a separation edge at the top of the tailgate which blends elegantly into the overall design of the rear end. This separation edge significantly reduces the uplift occurring at the rear at motorway speeds.

When travelling at higher speeds, it is the airstream which dominates the overall spectrum of driving noises – just below the recommended autobahn speed of 130 km/h, the air is already flowing around the car at hurricane-like speeds. In the new A6 allroad quattro the acoustic experts at Audi have succeeded in effectively muting the frequency range between 1,000 and 8,000 hertz, as noise in this range is particularly irritating to the human ear.

A triple seal system has been incorporated into the doors to soundproof all of the apertures where sound could enter. When the windscreen wipers are not operating they drop down into a recessed rest position to avoid creating any extra wind noise.

Even when they are in action, the windscreen wipers make surprisingly little noise – this is the result of the new flat wiper technology with its ingenious air routing and of the blades with their integral spoilers.

Permanent safety: adaptive headlights and daytime running lights

Customers may opt to have the very latest in lighting technology fitted behind the clear-glass covers of the A6 allroad quattro headlights, in the form of a single unit that combines xenon plus technology, the dynamic technology of adaptive light plus permanent daytime running lights.

The new A6 allroad quattro comes with light units in Audi's characteristic "tube" look too.

Featuring anthracite-coloured trims, the tubes for high and low beam appear to almost hover freely in the air, giving the front-end design of the car its very own touch of high-tech. A headlight washer system and fog lights in the front apron are included as standard on all models.

There is a choice of three different headlight versions: standard halogen headlights in free-form technology, xenon plus headlights and xenon plus with the dynamic adaptive light system. With this last top-of-the-range variant, the ellipsoidal module for the high-beam and low-beam headlights pivots in synchronisation with the line of the road or a bend at speeds between approximately 10 and 110 km/h. This greatly improves illumination of the road in front of the vehicle and to the sides. System control takes a range of parameters into account including vehicle speed, steering angle and yaw rate.

Extremely economical: daytime running lights

The significant boost to safety offered by permanent operation of the headlights throughout the day was previously associated with increased energy consumption, with an extra 0.2 litres of fuel being burned every 100 kilometres. It is this drawback that has prevented the wide-scale introduction of this technology in Europe. Yet there is evidence to show that daytime running lights help to enhance driving safety, particularly when the sun is low in the sky.

With the low and high beams in the xenon plus headlights being integrated into the same – the outer – unit, the inner reflector remains free for the use of daytime running lights. A dimmed bulb serves as the source of light, while the other lights are switched off. The resulting increase in fuel consumption is negligible.

Extra-fast: LED rear lights

An attractive LED unit for the brake and tail lights is fitted in the rear lights of the new A6 allroad quattro in conjunction with xenon plus headlights. As well as a long operating life of at least 10,000 hours and a cut in energy consumption of up to 80 percent, the main advantage of this technology is its much shorter response time.

Whereas conventional bulbs take around 200 milliseconds to reach their full brightness, LEDs achieve their full output in less than one millisecond. Drivers following behind will thus recognise much more quickly that the brake lights have come on, giving them more time to react. The emergency stop warning function included as standard is another safety-enhancing feature: if the driver applies the brakes sharply, the hazard warning lights are automatically activated for a certain period to warn drivers behind.

The LED units also add a striking, sporty touch at the rear of the car – the distinctive design of the rear lights gives the tail an unmistakable appearance, with their elegant, sweeping arrangement producing a wide, flat look.

Sporty and versatile: the luggage compartment

The new Audi A6 allroad quattro is geared towards sporty and active customers, and its spacious, highly versatile luggage compartment has been designed with precisely such people in mind. Even the basic configuration offers 565 litres of load space and this can be extended to 1,660 litres by folding down the asymmetrically split backrests – which can be done without having to remove the head restraints. Compared to the outgoing model, these dimensions represent significant increases of 110 and 70 l respectively.

Nothing less than the high quality of the materials in the luggage compartment and its lavish finish would be good enough for Audi. Countless meticulously thought-out details set a new benchmark for this class by virtue of their tremendous versatility. Both the net partition and its housing have been designed for straightforward attachment. The net's housing is separate from the retracting luggage cover, with both components having a lightweight, slimline construction.

All new A6 allroad quattro models have two securing rails recessed into the floor of the level, 1.05-metre wide load area, plus a total of four fastening rings. The elegantly styled, solid rings can be slid along the rails and locked into position, allowing all manner of luggage items to be safely secured in place if required. Two bag hooks as well as an additional stowage net on one side are also included. A lockable side compartment can be supplied as an optional extra, for keeping objects hidden from prying eyes.

The load floor can be folded up as a standard feature and can be locked in a variety of positions to divide up the load area. Not only does this provide scope for stowing smaller objects in a manner that prevents them from sliding around, it also provides access to the lower stowage area, where a large plastic tray can be found. This tray is ideal for dirty hiking boots after a hike in the mountains or wet snowboard boots after a day on the slopes.

For sports enthusiasts: ingenious options

A number of options are available to A6 allroad quattro customers for enhancing the rail system's versatility yet further. Take the telescopic bar, for instance, which can be engaged in the two rails to divide up the luggage compartment. Additional support can be provided by a retaining strap, which also clicks into place to either securely lash objects against the sides of the luggage compartment or divide up the load space crossways. Then there is the cycle rack system which provides a neat solution for transporting two mountain bikes securely.

The large storage box for the luggage compartment is a particularly versatile item. It can be secured to the rails in two different positions: with its opening facing to the rear, it can be used for storing smaller items of luggage and for dividing up the luggage compartment.

When pushed up flush against the rear seat with its opening facing forwards, the box can be accessed via the load-through hatch in the rear seat, and is thus transformed into an extra storage compartment that is safely out of sight from inquisitive eyes.

The optional reversible mat has an exclusive velour finish in the interior colour on one side; when turned over, its rubberised, easy-to-clean surface protects the load area floor. The reversible mat also incorporates a fold-out section that can be pulled down over the bumper. This protects the bumper during loading and unloading, or provides a clean surface for sitting down on, when changing your footwear after a hike, for example.

The removable ski and snowboard bag is another new feature that will be of particular interest to winter sports enthusiasts. Winter sports equipment can be packed away swiftly in the bag outside the car, then stowed inside without the interior becoming dirty or even wet.

The tailgate is released by means of an electrically controlled catch as standard, with a hydraulic drive available on request. With this option fitted, the tailgate can be closed by merely pressing a button on its edge; opening can be initiated at the push of a switch in the driver's door or by pressing a button on the remote control key. The tailgate can be programmed to open to any angle up to the maximum opening angle.

The aluminium roof rails with their smart twin-armed supports serve as the solid basis for a wide range of carrier systems, allowing cycles, skis or luggage boxes to be transported on the roof. The maximum permissible roof load is 100 kg, some 25 kg more than is generally the case.

The A6 allroad quattro is a multitalented vehicle that is perfect for sports enthusiasts. Its air suspension doubles as a self-levelling device, enabling a high payload of 630 kg for all engine variants. The braked trailer load is likewise very high – as much as 2.1 tonnes, depending on the engine. In conjunction with the optional swivelling trailer hitch, a special trailer function is added to the ESP stabilisation program.

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