To the Doctor:
I have a question concerning my car (a 1999 Toyota Camry LE) that has been troubling me for quite some time now.

Whenever am on the road, I always here a 'growling' low-pitched sound coming from the front end of the car, specifically near and around the tires. When I accelerate, the sound becomes louder, and the opposite is true when I decelerate. Sometimes it becomes even louder when I am on the highway and apply my brakes to take an exit, for example. Since the problem has always been there, I had the tires balanced last August and even had brand new rotors and all front brake parts changed to see if I'd notice any difference, but still the problem persists.

Now, what could be the problem? Is it something to do with the tires? Were the wrong type of tires installed on my car? (I had them installed in December 2008.) Should I buy new ones that are recommended for my car? Do you have any suggestions that might be of assistance to me? Please help me out with whatever information you can provide before I lose my mind.

The Doc Says:
Without being able to hear the sound firsthand, it certainly appears from your e-mail that you're describing a symptom emanating from the tires themselves. Different tires feature different tread block patterns, which can create different sounds on the road. For instance, "mud" tires with big tread blocks often cause a loud humming when driven at highway speeds. The hum is caused by air compressing and decompressing as the blocks roll over the highway. Different types of tires create different sounds, with some new tires being marketing specifically for their silent ride. Generally, tires with smaller tread blocks will have less noise, while those with larger tread blocks (like off-road or performance tires) will make more noise. If your "growling" started about the same time you purchased the new tires, I'd bet the noise is simply a byproduct of the tires you selected.

However, you can do things to mitigate the tire noise. A tire that is fully inflated will generate less noise than an under-inflated tire, so make sure your tires are aired to their recommended pressures. Also, if you're carrying around a lot of extra weight in the trunk or back seat of your car, you might consider lightening the load, because a tire that is heavily loaded will generate more noise than one that is not loaded down very much.

The advice described above is for informational purposes only. It cannot and should not be used in lieu of an actual, physical inspection and diagnosis by a trained mechanic or automotive technician. The opinions and advice offered herein are not intended to diagnose automotive problems or component failures; they are simply intended to provide information on what could be transpiring. VehicleMD accepts no liability resulting from actions taken as a result of this advice.