My car is making a weird noise at around 20mph. Basically it is a road noise coming from my back tire that sounds a little like an exhaust drone. At first I thought it may be my exhaust because I have AWE cats and the gundo hack but even if I put the car in neutral and cruise at that speed it does it. It isn't very loud but has a mix of a tire noise with droning and drives me crazy. Any idea what it could be? My tires aren't new but they aren't totally worn our either.

 

Have you tried coasting downhill (20+ mph) in neutral with the engine off? You might have to first drive to another state! Try isolating the potential issues...

 

If you've already checked the tires, it could be a wheel bearing, or a brake component that needs attention. If you put he car up on stands and spin the rear wheels is there any drag or wobbles with the wheel, or any loose suspension parts?

Could be a cracked rotor face, a dragging brake pad or something of the like.

 

Are your rear tires less than 50%? I had a bad wheel bearing and now that my tires are getting really low, it sounds almost the same...definite drone and road noise.

 

1. How old are the tires?
2. How many miles on the tires?
3. Do you have uneven wear on the rear tires?

You might want to jack up the rear of the car and inspect the tire and wheel bearing. If you cant then take it into a shop

 

some performance tires that I ve had start getting louder as they enter more than 1/2 their life.