In a combustion-powered vehicle, the main car noise a driver hears (except if there is an issue with the vehicle) is the engine. This car noise is the result of thermodynamics: as heat energy is transformed into mechanical energy to propel the car, the engine’s cylinders produce pulsations (sounds) that are emitted via the exhaust valve.
Electric car noises: what to expect?
Are electric cars quieter than petrol cars? An electric vehicle, by its very nature, doesn’t have an engine. Instead, it has a motor system powered by a battery. Unlike thermodynamics, electromagnetics doesn’t result in noise emissions. As a result, the motor is almost totally silent.
Perhaps even too silent! Electric vehicles are much quieter than petrol cars. At low speeds (below 30 km/h) they are so much quieter that ‒ to reduce the risk of accidents for pedestrians ‒ the EU has introduced a regulation for electric vehicles, imposing a minimum of 56 decibels at low speeds.
This is the equivalent of the noise a dishwasher makes, an office computer or the quiet buzz of a near-empty restaurant. On average, combustion engine cars are closer to 65 decibels, which is the equivalent of a busy classroom.
The electric car noise that you will hear, however, is the tyre noise: the sound of the tyres rolling over the road surface (which is often described as a low roaring sound in the car, a bit like a background noise).
Do electric car tyres make more noise than combustion-powered ones? No. If you hear more the tyre rolling over the road surface, it’s because an electric motor makes almost no noise. You become more sensitive to any additional noise.
This tyre noise depends on the condition of the road that generates vibrations in the cabin. Even on the highway you don’t always find the same kind of road surface. And it’s here that tyre, and automobile manufacturers have a real challenge on their hands.
Tyre noise also depends on the speed you drive. The faster you drive, the more you hear a whistling sound from the car. This is something Michelin works very hard on in order for drivers to enjoy the electric experience.
For Michelin, the solution to minimizing this tyre noise is a complex combination of the tread pattern and MICHELIN Acoustic® technology, which reduces perceived interior noise by up to 20%. (1)