Decibel X didn't work for me as I got very low unrealistic values (livingroom with TV on 23db where other apps show 60db)Can you quantify the sound level with a decibel meter. Is the noise proportional to speed? I have Decibel X app on my phone (there is a free version). It will give you instantaneous values as well as average and maximum during your recording period. Obviously the readings will be influenced by the road surface and noisy vehicles that pass you. My Mach E is quiet and any noise I do hear is road noise from the tires on certain concrete roads and/or wind noise. I have not taken a db reading on my Mach E, but I may after reading about your troubles. I suspect it will read in the 60's and is quieter than my Lincoln MKX which is pretty damn quiet. Sorry this has to spoil your experience; that has to be frustrating.
I took another app and got the following results
- Standing still, contact off: 27-30db
- 35km/h smooth concrete: 57-60db
- 80km/h rough concrete: 66-72db (some spots were rougher than other spots)
- 100km/h highway medium rough concrete: 68-72db
I didn't notice any DB difference on the part of the highway which has smoother concrete and on which the annoying low noise is much less than on the rougher concrete which makes me believe that the loudness of the annoying sound is limited but the annoying aspect is the low frequency tone it makes .