Audi has revealed how the e-tron has a drag coefficient of 0.28, a figure the auto maker says helps the EV achieve a range of more than 400km (248.5 miles) in the WLTP cycle.
On the aeroacoustics test rig at the Wind Tunnel Centre in Ingolstadt, Germany, Audi engineers optimized the vehicle’s drag and noise. The facility, the world’s quietest vehicle wind tunnel, houses a low-noise rotor measuring around 5m (16.4ft) in diameter and with an output of 2.6MW, the fan produces wind speeds of up to 300km/h (186.4mph). The e-tron prototype underwent more than 1,000 hours of testing in the tunnel.
To achieve a drag coefficient of 0.28, the Audi engineers developed a wide range of aerodynamics tools. Some of these technical solutions are evident at first glance, while others fulfill their purpose hidden away from sight.
Thanks to these solutions, the drag coefficient for the Audi e-tron prototype is almost 0.07 less than for a comparable, conventionally powered vehicle. With a typical usage profile this set-up increases the range by around 35km (21.7 miles) per battery charge in the WLTP cycle.