Just bought a 2021 Mazda 3 Premium FWD with just under 36000k on it. It started making a slight humming noise when going from 30-40 mph, increased to a much more noticeable noise from 62-68 mph. It’s like a low frequency oscillating humming can’t even really tell where it’s coming from. It seems very consistent and doesn’t change based on the rpms. Brought it to the dealer cause its still under warranty. The collision center manager told me today he thinks it’s something to do with the tires, but they’re brand new tires! Any ideas what it could be?
look at tires and wheel bearings first those are the two biggest causes. certain tire treads can make more noise, but check to make sure they are installed correctly and that they don’t have weird/uneven wear. if they have uneven wear, that points to an alignment or suspension issue. if all checks out on that front it’s most likely a wheel bearing