Sound of Nature

Wind is an exciting phenomenon. When wind meets a solid object, such as a tree, and is forced to go around it, that creates a vortex. Much like a swirl in water. Within such a vortex the air expands slightly, air pressure decreases and the expansion of the air triggers an impulse. When a number of these impulses reach our ears, we perceive the wind to be howling. We hear the wind but cannot see it. We see its effects, trees swaying, ripples on the water. With electric cars, the exact opposite is the case: You’re moving, and yet you hear next to nothing. No sonorous hum, no subtle purr of pistons going up and down in cylinders.

In the Audi Q7 e-tron 3.0 TDI quattro, the world’s first plug-in hybrid SUV with TDI and quattro drive, you notice it right when you press the ignition. That has less to do with the typically elaborate noise insulation in an Audi and more to do with the high-performance, high-voltage battery that makes the Audi Q7 an e-tron quattro. Push the ignition and at first all you hear is … nothing. With every cold start, as far as the battery charge level allows, the system automatically selects EV (which stands for electric vehicle). If you stay in that mode, the Audi Q7 e-tron quattro will take you up to 56 kilometers in pure electric mode—marking a new best for plug-in hybrid vehicles. It’s all made possible by the 168 battery cells in a liquid-cooled lithium-ion block mounted beneath the trunk that push out 17.3 kWh of power. Yet despite all those battery cells, the luggage compartment volume of max. 1,835 liters is still unparalleled in a direct comparison with the competition.

It’s up to the driver which mode—EV, hybrid or battery hold—he tells the system to use. In “hybrid” mode, the control electronics automatically regulate the interplay between the 190 kW six-cylinder TDI unit and the 94 kW electric motor to achieve maximum efficiency. Once a destination is fed into the navigation system, the ideal operating strategy—electric, hybrid or combustion—is automatically calculated and precisely tailored to the route.—also after the adaptive cruise control (ACC) has been activated. The SUV then accelerates up to the preselected speed and maintains it. But that’s not all. In countries with the requisite density of navigation data, the car’s predictive efficiency assistant allows it to automatically slow down within system limits in antici-pation of a speed limit, a gradient or a tight bend, to then accelerate again once the particular situation has passed. Visual feedback is provided by the MMI display’s energy flow reading or the power meter or rev counter on the Audi virtual cockpit that comes as standard. This tells the driver at any given moment whether just the TDI engine or just the electric motor—or both—are propelling the SUV.

Charging process: After hooking up to a public charging station or industrial power socket (7.2 kW maximum charge power), the range of up to 56 kilometers in pure electric mode will be available again in around 2.5 hours.