It could be a few things. Does the sound change on turns? Are the tires worn evenly or are they feathered? Also, 40 PSI is a good bit of air for a passanger tire. In fact, it may be over the manufacturers recommendation. Some max at 35, others at 44. Also, you should refer to the manual for tire pressure, but I found tires do well when they are at 35 PSI.
Let me know what you find.
Monday, March 9th, 2009 AT 7:21 PM