The only drawbacks to runing it cooler that I am aware of is that if the oil does not get hot enough, or hot long enough, it will not evaporate the moisture caused by condensation out of the oil. Also, your gas mileage may decrease a tick due to the increase in parasitic losses caused by the slightly thicker cooler oil and the fact that more heat increases fuel atomization. And lastly and most likely the primary reason for the high temps, your emissions will most likely increase with a lower temp. The advantages on the other hand are numerous. First is the increase in reliability as well as the extra safety margin for running it cooler. Also, cooler is much more tolerant to adverse conditions (i.e. poor fuel quality, high ambient temps, tunes a little out of whack, fuel delivery problems, etc.). Also, cooler motors, though in theory are less efficient, will make more power than hotter motors due to the ability to keep the intake charge cooler and consequently denser (after several dyno sessions with my nearly stock set up, it was clear it made the most power right around 180 deg... it would start to fall off as it got hotter and actually dyno's less cooler as well). I currently run a 160 stat and use the fans to keep the temps as close to 180 as possible (low temp on at 175, high temp on at 185 or ther abouts).