Audi A2 -- fascinating technology and a new form of agility
At Audi, visions are rapidly transformed into reality: when Audi unveiled the design study of an aluminium-bodied car under the name of Al2 at the 1997 Frankfurt Motor Show, it was giving the automotive world a glimpse of the shape of things to come.
Just two years on, at this year's Frankfurt Motor Show, Audi will be presenting the production model based on that design study: the Audi A2. With its refined ASF Audi Space Frame, this is the first volume-production car in the world to have a body made entirely from aluminium.
The A2 resolves various seemingly irreconcilable contradictions. It is the lightest car in its class, yet at the same time has a reassuringly substantial, mature appearance. It is a common-sense car that is nevertheless not dull. Despite its low fuel consumption, it is highly enjoyable to drive. Its exterior dimensions are compact, but it affords an exceptional standard of occupant comfort.
The A2 is a particularly impressive illustration of Audi's motto for the Frankfurt Motor Show "In Future - Audi".
The Audi A2 is a genuine Audi in every respect: driving enjoyment, technology and design.
Audi Space Frame
The Audi A8, which went into production in 1994, established new standards of deluxe-class cars. Its all-aluminium body, produced using the ASF principle, represented a quantum leap in the development of lighter vehicle bodies that nevertheless exhibit high strength. The weight reduction cuts fuel consumption and renders the car more agile. The ASF design moreover affords optimum protection for a car's occupants.
Whereas annual production of the Audi A8 is running at around 15,000 units, Audi anticipates that the annual sales volume of the A2 will be at least 60,000 cars. The ASF concept thus needed to be reviewed in the light of high-volume production requirements.
With its refined Audi Space Frame concept, the Audi A2 pioneers the use of aluminium technology for volume-production cars and provides a basis for Audi's planned "three-litre car" - i.e. a car capable of clocking up 100 km on only three litres of fuel.
The A2's forward-looking concept once again demonstrates Audi's innovative capabilities, technological lead and sense of responsibility for the world of tomorrow.
A new dimension to aluminium technology
The core slogan "Fascinating technology and a new form of agility" expresses the character of this new Audi in a nutshell. Thanks to its aluminium concept with Space Frame, the tare weight of the Audi A2 is a mere 895 kg - all of 150 kg lower than what vehicles of this size usually weigh. Technically speaking, however, the A2 is certainly no "lightweight". In fact, it is brimming with ideas and innovations that have never before been used on volume-built cars.
The idea behind the ASF concept is basically the following: the panel sections are integrated into a high-strength aluminium frame structure, such that they have a self-supporting effect. The Space Frame proper consists of extruded sections which are connected by vacuum die-cast nodes. This frame, in conjunction with high-strength aluminium panels, forms a highly rigid body that is nevertheless very light.
Compared with the A12 design study, the Audi Space Frame has been further refined. One significant difference is the reduced number of individual components thanks to the use of evolutionary aluminium technology. For instance, the high-pressure aluminium castings used at the front roof posts are of a complexity that surpasses any element used in the aircraft construction sector, and whose detailed use of shape would warm the heart of any sculptor. These aluminium- structures, with multiple reinforcements and varying wall thicknesses, achieve a strength that would entail a substantial weight increase if made from steel.
This drive to implement advanced joining techniques ensures that the conflicting objectives of maximum strength and minimum weight are resolved convincingly. The roof frame consists of aluminium profiles shaped by an internal high-pressure technique. Thanks to this technique, it is possible to obtain a profile cross-section which varies several times along its length, ideally reflecting the requirements which each zone has to meet, all the while keeping the weight to an absolute minimum. The entire body, including doors and tailgate lid, is over 40 percent lighter than an equivalent structure of steel.
The side of the car is another masterpiece of pioneering metalworking technology at the cutting edge. The entire section, from the front roof post to the luggage compartment edge, including the door cutouts, is made from a single extruded aluminium section. Thanks to Audi Space Frame technology and the use of aluminium, the number of main body components has been reduced and the weight brought down correspondingly.
Other points in favour of the aluminium concept are the outstanding ease with which aluminium can be recycled, and the positive energy balance that results from its re-use. The energy consumption throughout the vehicle's lifetime, including the production process, its entire service life and its final reprocessing, is well below the energy consumption of a car of this size and performance class when manufactured using conventional means.
The face of progress
The A2's progressive design reconciles two apparent contradictions: agility and robustness. Whereas the gently ribbed roof and expansive rear window are indicative of its lightness and subtlety, the sturdy, high-shouldered vehicle body creates an impression of considerable substance, indicating security and protection.
The engine and passenger compartments on the Audi A2 are kept visually distinct by the two-box design. This concept, in conjunction with a progressive design, gives the Audi A2 a very mature appearance.
The clear-cut lines with accentuated joints and the consciously geometrical wheel arches convey an emphatic formal idiom. The Audi A2's front end is particularly powerful. The principal design elements are the striking headlights, the bumpers almost fully integrated into the overall shape, and the design feature of the radiator grille which blends into the "service module" thanks to the chrome trim surrounding both.
The fully glazed tailgate lid extends all the way down to the bumper, for convenient loading of the spacious luggage compartment (390 litres of volume, or 1085 litres with the rear bench seat folded down). The rear spoiler optimizes the aerodynamics and deflects the airflow over the window in such a way that it is kept clear in wet weather, even without a wiper.
The outstanding drag coefficient of 0.28 assures the Audi A2 the best aerodynamic performance in its class.
Space Floor Concept for optimum use of space
The Audi A2, with its relatively compact dimensions of 3.82 m long, 1.67 m wide and 1.55 m high, is surprisingly roomy and comfortable inside. The feeling of spaciousness inside the Audi A2 is quite remarkable. The driver, front passenger and occupants of the rear seat have plenty of headroom, leg room and elbow room.
The "Space Floor Concept" provides the ideal basis for a relaxing, anatomically correct seated position for the rear passengers in particular.
The secret of the Space Floor Concept is the Audi A2's sunken rear footwells. The rear passengers can in effect place their feet in a tray, keep their legs at a natural angle and thus sit in an anatomically correct, relaxed posture.
The interior is remarkable for its versatility. The rear seats of this four-seater car can be folded down either individually or together, and can also be removed individually. A three-seater rear bench can be ordered as an optional extra.
The "Open Sky System" is a glass roof, available as an optional extra, which lets in plenty of light for all occupants and, if desired, fresh air too. It extends across the entire width of the roof, and back as far as the tailgate window.
World first: the service module
The Audi A2 also redefines the standard when it comes to ease of servicing. It is the world's first production car to have a "service module".
On the Audi A2, a folding flap takes the place of the conventional radiator grille; the oil dipstick and filler caps for engine oil and washer fluid are readily accessible behind this flap, for maximum convenience. The service module permits easy checking and topping-up of fluids by the driver at the filling station.
The complete engine hood therefore now need only be opened by the service workshop. Instead of simply folding up, the entire hood is detached once the quick-acting couplings behind the service flap have been released. To round off the very customer-friendly service concept, the Audi maintenance intervals have been extended to 2 years or 30,000 km, whichever is the sooner.
The technical basis of a new form of agility
The Audi A8 has demonstrated that Audi Space Frame technology provides an ideal basis for outstanding road behaviour. This is because the high structural rigidity of the body acts as a strong backbone for the suspension, thus permitting ultra-precise suspension settings. And the lower weight means that agile road behaviour can be obtained with a relatively low engine output.
The Audi A2 demonstrates that the high practical utility of a compact vehicle can be combined with maximum driving enjoyment and extremely low fuel consumption.
The A2's suspension combines ultramodern electronic components, such as ABS anti-lock braking as standard, EBD electronic brake-force distribution and the ESP electronic stability program, with the proven technology of a McPherson spring-strut axle at the front and a torsion-beam rear axle.
Audi will be displaying two engine versions of the A2 at the 1999 Frankfurt Motor Show, each of them with an output of 55 kW (75 bhp) - one TDI and one spark-ignition version.
At first glance, the Audi A2 appears to have less performance than its immediate competitors. In actual fact, however, thanks to the Audi A2's aluminium concept, every kilowatt of engine output on this car has less weight to propel than on a conventional vehicle. In other words, it has a very good power-to-weight ratio which helps it to move with mercurial ease. For instance, the outstanding flexibility values - which are critical to good overtaking ability - make for nimble, relaxing driving.
The diesel version is a three-cylinder TDI with pump injector direct injection. It has a displacement of 1.4 litres and an output of 55 kW (75 bhp). At this swept volume, the three-cylinder diesel is an ideal concept for minimal fuel consumption. In this version, the Audi A2 clocks up a fuel consumption of only 4.2 litres per 100 kilometres (overall consumption acc. to 93/116/EC), yet its road performance is that of a mainstream car: it too achieves a top speed of 173 km and accelerates from 0 - 100 km/h in 12.1 seconds.
The Audi A2 with 1.4 litre spark-ignition engine, again with an output of 55 kW (75 bhp), is no less agile. This engine, with multipoint fuel injection, propels the Audi A2 from 0 to 100 km/h in 12.0 seconds and on to a top speed of 173 km/h; it achieves a very modest average fuel consumption of 6.1 litres per 100 km (overall consumption acc to 93/16 EC).
Both engine versions have a 5-speed manual gearbox.
The Audi A2 already satisfies the forthcoming European emission limits (1.4 TDI: EU 3, 1.4 spark-ignition: EU 4).
High standards of safety
As on the Audi A8, the ASF structure constitutes an ideal basis for high passive safety. The high-strength frame structure surrounds the occupants to protect them like a cage, impact energy is converted particularly effectively and the occupant cell is by and large preserved.
With two airbags at both the front and sides, belt tensioners and belt force limiters, plus the optional SIDEGUARD head airbags that are available for all seats - a unique feature on a car of this class - the Audi A2 assures supreme standards of safety for all its occupants.
The equipment and data specified relate to the model range available in Germany. Errors and omissions excepted.
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