My car has always run cool, ever since I bought the car ...

The car never makes it past around 155 degrees .. I never really thought much about it, the cooler the better right? Well, I've started to realize this could be a big reason for my car running so rich (10.2:1) .. do you think running this cool could actually be hurting me? Just curious before I go through the bother of replacing the tstat with a 180.