Come on, feel the (electric supercar's) noise
Performance marques are divided over artificially re-creating the sound of a high-end combustion engine.
Artificial engine sounds could be a way of life for electric supercars of the future, as manufacturers look at maintaining the character of machines that have built their reputations on distinctive sounds.
However, other manufacturers are taking the opposite stance, refusing to re-create something that is not authentic to the engine and preferring to emphasise the distinctive sounds of an electric motor or petrol-electric hybrid car.
Porsche says it may simulate the engine sound of its upcoming 918 Spyder to alert pedestrians - especially the blind - and give drivers the full V8 feeling when the supercar is running in electric-only mode.
The man in charge of research and development at Porsche told Drive the brand could fit external speakers to ensure drivers always hear the bellowing 3.4-litre V8 that teams with three electric motors to make the 918 Spyder one of the fastest cars conceived. The 918 Spyder is a plug-in electric car that can drive for up to 25 kilometres as a pure electric car.
It also has three hybrid drive modes that can make almost 540kW of power and use a claimed average of 3.0 litres per 100 kilometres; 23 per cent less than the world's most popular hybrid, the Toyota Prius.
"We have the sound and we will just have to record it," said research and development boss for Porsche, Wolfgang Durheimer.
"Sound generation is no problem. The technical devices are already in development. We just have to decide [if it's right for a Porsche]." Performance cars often trade on their engine sounds. Aussie V8s have a distinctive flutter, while Ferrari V8s let out a howling scream.
Fake engine sounds open all manner of possibilities for manufacturers. They could allow city runabouts to sound like purebred American muscle cars or sports cars to sound like trucks. Or you could have your car sounding like a Ferrari formula one car or a V8 Supercar.
Noiseless cars are being looked at as a safety issue, with pedestrians often relying on sound to determine if a car is coming.
Nissan has developed a chime, a melody and a futuristic whir, while the US Congress is looking at a measure requiring vehicles to use non-visual warnings for pedestrians.
A US National Highway Traffic Safety Administration technical report released last year found a higher rate of pedestrian and cyclist deaths from hybrid cars compared with vehicles with conventional engines. However, the performance arm of Mercedes-Benz, AMG, says the upcoming electric version of the SLS Gullwing will not emit a fake V8 rumble.
While AMG has some of the best-sounding V8 engines following special exhaust-tuning to tailor the noise, its head of engine development, Friedrich Eichler, said the company would never create a fake V8 soundtrack for the car.
"You can get a soundtrack for the speakers in the car so you can make it sound like a combustion engine but I don't like that idea at all," he said. His team is working on enhancing the sound of the electrical engine components and making them pleasing to the ear.
"It is possible to shape the character of the electric motors and make them sound attractive," he said.
He has a team of engineers working on the sound for the car and said it was important because the noise of an engine had a psychological effect on the driver.
He said the development team could also make the engine appear to change gears to retain the driver involvement of a normal combustion-engine car: "We are looking at possibly having paddleshifts on the steering wheel. It could be possible to make the engine change in steps."
Various manufacturers have talked about simulated engine sounds, with US electric sports car maker Tesla trialling the concept. Engine sounds are crucial to vehicle design and can help define a brand. Lexus is renowned for quiet, refined engines but in recent years the Japanese luxury car maker has responded to criticism by allowing some classic V8 burble into the cabin.
For some manufacturers, engine sound is not an issue. Rolls-Royce is known for effortless performance, well suited to the easily accessible torque of an electric motor. Rolls-Royce has said it believes its "waftability" is suited to an electric motor.