Audi e-tron Concept
Audi presented the highlight of the IAA 2009: the Audi e-tron Concept, a high-performance sports car with a purely electric drive system. Four motors - two each at the front and rear axles - drive the wheels, making the concept car a true quattro. Producing 230 kW (313 hp) and 4,500 Nm (3,319.03 lb-ft) of torque, the two-seater accelerates from 0 to 100 km/h (0 - 62.14 mph) in 4.8 seconds, and from 60 to 120 km/h (37.28 - 74.56 mph) in 4.1 seconds. The lithium-ion battery provides a truly useable energy content of 42.4 kilowatt hours to enable a range of approximately 248 kilometers.
The performance figures are by no means the only evidence of the consistent and holistic strategy. The design makes it clear that the Audi e-tron Concept belongs in the major leagues of sports cars, and the package takes into account the specific realities of an electric vehicle. The battery is directly behind the passenger cabin for an optimal center of gravity and axle load distribution.
The Audi e-tron Concept is able to freely distribute the powerful torque of its four electric motors to the wheels as required. This so-called torque vectoring allows for dazzling dynamics and an undreamed-of level of agility and precision when cornering.
Audi has taken a new and in some cases revolutionary approach to many of the technical modules. A heat pump is used to efficiently warm up and heat the interior. The drive system, the power electronics and the battery are controlled by an innovative thermal management system that is a crucial component for achieving the car's range without compromising its high level of interior comfort. Networking the vehicle electronics with the surroundings, which is referred to as car-to-x communication, opens new dimensions for the optimization of efficiency, safety and convenience.
Electric drive systems are still very much outsiders. The first vehicles of this type took to the roads around 1900, yet in 2009 no volume car manufacturer has a car powered exclusively by batteries in its lineup. Fewer than 1,500 electric vehicles are currently registered in Germany, corresponding to only 0.035 percent of all registered vehicles.
Yet electric driving potentially offers numerous advantages. Electric cars reduce the dependence of transportation and the economy on the raw material petroleum. They produce no direct exhaust emissions and thus ease the local burden on the environment. Electric drive systems are also significantly more efficient than combustion engines, consequently making them easier on the customers' wallets. Other strengths include sportiness and the fun they bring to driving. All of the torque is essentially available the moment the driver steps on the accelerator, allowing for breathtaking acceleration.
There is still a lot of work to do before electric cars are ready for volume production, however. The greatest challenge is the integration of the energy storage system. Acceptable range and performance requires a traction battery that is heavy and takes up a lot of space. Audi is taking a new approach to offset these disadvantages - a holistic approach with a specific vehicle package, a systematic lightweight construction concept and an optimal configuration of all components for the electric drive.
The most important development related to batteries for electric drives are lithium-ion cells. Numerous experts throughout the world are working on their further development for use in cars, with the primary objectives being to reduce weight and increase capacity and performance. Audi has also opted for this technology, both for use in a hybrid production vehicle, such as the upcoming Q5 hybrid, and in the e-tron test platform.
The requirement specification for the concept vehicle goes far beyond battery technology and the replacement of the combustion engine with an electric drive system, however. The Audi development engineers decided back in the concept phase to design practically every component and technology based on the new requirements of electric mobility. The interaction of all elements has a decisive influence on the factors efficiency, range and practicality.
The caliber of the car is apparent to the observer at first glance. The Audi e-tron Concept has a wide, powerful stance on the road. The car body seems almost monolithic; the closed rear end appears powerful and muscular. The trapeze of the single-frame grille dominates the front end and is flanked by two large air intakes. The top of the grille merges into the flat strips of the adaptive matrix beam headlamp modules with their clear glass covers. High-efficiency LED technology is used for all lighting units - a matter of honor for Audi as the worldwide pioneer in this field.
The headlamps are the core of a fully automatic light assistance system that reacts flexibly to any situation. The new technology recognizes weather conditions and adapts the illumination to rain or fog. The technology at the heart of the light assistance system is a camera that works together with a fast computer to detect oncoming traffic, recognize lanes and measure visibilities, such as in the event of fog.
Optical and functional references to the new drive concept characterize the interior design. They establish an advanced connection between proven Audi genes and new formal hallmarks. Typical for the Audi design language is the reduction of the architecture, controls and flow of information to the essential in favor of visible lightweight construction and a tidy overall impression.
The dash appears to float and has a curve that extends laterally into the door panels. With no need to allow for a transmission, shifter and cardan tunnel, the designers took advantage of the opportunity to create a particularly slim and lightweight center tunnel and center console. The flush gear selector, with which the driver chooses between the modes forward, reverse and neutral, emerges from the tunnel when the vehicle is started.
The cockpit of the Audi e-tron Concept is also oriented toward the driver - a further characteristic Audi trait. Instead of the classic instrument cluster, the concept car is the first Audi to be equipped with a large, fold-out central display with integrated MMI functions. It is flanked by two round dials.
The MMI is controlled via a scroll pad with a touch-sensitive surface on the steering wheel ("MMI touch") - an element inspired by modern smartphones.
Four asynchronous motors with a total output of 230 kilowatts (313 hp) give the Audi e-tron Concept the performance of a high-output sports car. The concept car can accelerate from 0 to 100 km/h (0 - 62.14 mph) in 4.8 seconds if necessary, and goes from 60 to 120 km/h (37.28 - 74.56 mph) in 4.1 seconds. The torque flows selectively to the wheels based on the driving situation and the condition of the road surface, resulting in outstanding traction and handling.
The top speed is limited to 200 km/h (124.27 mph), as the amount of energy required by the electric motors increases disproportionately to speed. The range in the NECD combined cycle is approximately 248 kilometers (154 miles). This good value is made possible by the integrated concept: technology specially configured for the electric drive system combined with state-of-the-art battery technology. The battery block has a total energy content of roughly 53 kilowatt hours, with the usable portion thereof restricted to 42.4 kWh in the interest of service life. Audi uses liquid cooling for the batteries.
Source: Audi press