I went a little long on my last tire rotation and noticed that the middle of my front tires were almost bald while the edges were not as worn. The rears looked fine. When I rotated them, I lowered the fronts to 28 pounds hoping to even out the wear while keeping the rears at 35. I noticed tonight that my mpg dropped from the 14s to the 12s. Could the drastic drop be soley to the air pressure drop in the front tires or might there be something else going on? Thanks, Taro