My car (02 Mazda P5), makes a howling noise when i drive 40 MPH and over. Can anyone plesae tell me why that is? thanks in advance,.

 

wheel bearing maybe

 

I was going to say the same thing.

 

i dont think it is, I just change both front wheel bearing about 3 to 4 months ago. its a different sound.

 

This is EXACTLY what my Protege was doing when i bought it. The howling also started when the speed was reaching 40 MPH.
It seemed to come from the driver's side rear wheel. I also thought it was the bearing, so i replaced it, but the sound continued.
The only thing i could think of at this point was that it had to be the tire, because i had experienced the same thing in the past with one of my previous cars.
But just to test it out, i put my spare on and went for a drive - and bam, the howling was gone. So, knowing that it was the tire, i replaced it and the howl has been gone ever since.