Tire noise... or so I thought

[huyatgr]

I need assistance diagnosing what I thought to be tire noise. I want to restore my ultimate driving experience.

Backstory: I had Michelin Pilot A/S tires on my car with 35k miles on them. Over the past few months, the road noise went from "tolerable" to "I can't hold a conversation". Thinking it was just uneven wear, I had a new set of Pilots put on the other day.

The noise has improved somewhat, but when I get up to 40mph the purring starts. By about 60 mph, it reminds me of a propeller plane engine humming along. It doesn't matter what road surface I'm on. It sounds like the noise is coming from the rear wheels. I also have slight vibration that was not present before.

Any ideas on what I should have checked out? Is this something I should take up with my indy shop? I am just looking for some suggestions so that I don't get scammed.

Thanks!

[brettski]

If you shift the weight of the car does the tone change? (light swerving will be sufficent)? If it does it could be a wheel bearing. It could also be your diff on the way out, how many miles has your car done?