Tires: Had 2 tires on front replaced - Noise problerm, bf goodrich, oem tires

Question
I never rotated my tires on my 2005 Corolla S.  About three months ago I inflated my tires to 40 lbs in an effort to get better gas mileage.  I recently noticed the the front tires didn't have wear bars and looked like they needed replacing.  The tires OEM tires are Bridgestone Insignia SE 200 P195-65R 15 89S.  I went and had the fronts replaced.  The two new tires purchased are BF Goodrich Premier Touring tires same size with the rating 89T ... M S??  The installer put the new ones on the back and put the old back set on the front.   

I am now hearing a howling noise that varies with the speed and surface I am driving on. I believe the shop inflated all of the tires to 30 lbs a tire inflating them with nitrogen.  

Any thoughts????

Thanks....

Answer
Will,

First you should check the pressure yourself to be sure.  But 30 psi is what it is supposed to be, but there is no harm done if you add 3 to 5 psi more.  I think 40 was excessive and potentailly dangerous.

I'll bet the rear tires (now on the front) were on the rear much longer than 5,000 miles and that they have developed irregular wear as a result.

So you can either live with it and hope you develop a different wear pattern that isn't so noisy - or buy new tires.