Update:
Rotated the tires this evening to see if the howl goes away by moving the rears to the front. Checked to see if really dumb things weren't present, like maybe the tires were mounted by the store against the proper rolling direction. Everything looked fine there. Also made sure that air pressure was correct. It didn't look like any of the wheel weights were thrown off, which was another one of my theories for the cause. Pressure was fairly low (around 25 PSI, even though I topped it off just two weeks ago), so I had great hopes that the howl was going to go away. A quick spin around the neighborhood was disappointing. The low howl is still there.
I can't imagine that that I've got four bad tires, so I'm at a loss as to what is causing the problem. It's not so bad as to be unacceptably loud, but definitely there all the time, and it gets worse on slight turns, combined with a slight vibration felt in the foot pedals. It sounds to me like its coming from the front and being caused by the edges of the front tires reaching a harmonic frequency with the road.
Since my last set of KDWs lasted only 14K with the inner edge totally worn away, I'm beginning to suspect that maybe my problems are not with the tires, but are suspension-related. The car was four-wheel aligned by the dealer with the mounting of the Continentals, but I've wondered if I have worn tie-rods. Under acceleration, bad tie rods could lead to toe-out and worn inner edges. I wonder if this could be the cause of the noise I'm hearing on new tires that are supposed to be relatively quiet.
Lee K
