That doesn't make any sense at all then. Cars should sound like cars if you want to elicit the kind of response that a car would get in traffic, and should - if you want to go this way anyway - be as loud as a car is so that people will accurate judge its distance.
It's higher in tone so it's easier to localize, and the unique sound draws more attention. Any time an electric car passed me by with the whizzing sound, it just sounded like it was at the correct volume level for the application. It's definitely more pleasing than good old diesel rumble or some hot shot with the popping exhaust.
