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.
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.
Four asynchronous motors with a total output of 230 kilowatts (313 hp) give the Audi e-tron 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.
The direct rack-and-pinion steering gives finely differentiated feedback. Its electromechanical steering boost varies with speed, so that the e-tron only has to provide energy while steering, and not while driving straight ahead.
As befitting its status, the Audi concept car rolls on 19-inch tires with a new blade design. 235/35 tires up front and 295/30 tires in the rear provide the necessary grip.
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