The better an electric car’s aerodynamics, the further it travels: With a drag coefficient of 0.28, the Audi e-tronprototype achieves a top result in the SUV segment. This figure is a decisive factor in the everyday range of more than 400 kilometers (248.5 mi) in the WLTP cycle. The virtual exterior mirrors constitute one highlight in the aerodynamics concept of the all-electric premium class model. The scenario: endurance tests in the wind tunnel In front of the low-noise rotor measuring around five meters (16.4 ft) in diameter, the Audi e-tron prototype stares into the eye of the hurricane. On the aeroacoustics test rig in the Wind Tunnel Center in Ingolstadt, the world’s quietest vehicle wind tunnel, the Audi engineers optimize drag and noise under extreme conditions. Both are crucial for a car’s efficiency and comfort. With an output of 2.6 megawatts, the fan produces speeds of up to 300 km/h (186.4 mph). The Audi e-tron prototype was put through over 1,000 hours of testing