ive got 33 AT's on 15x8 rims. the outer inch or two dont make contact with the ground at 35 psi. i took the down to 30 , now the outer edge makes contact, but the inside edge still doesnt touch.i think its causs the tire rolls over more now on corners. should i air them down more? should i run them at 35 and not worry about it?i dont want to wear the tires out prematurely , and i dont want to hurt my MPG either.