denny is right on it... probably your first 500-1000 miles its going to run a little hotter hotter than usual... and also yes lighter oil will dissapate heat better than heavey oil.... if you are really concerned about the temp.... run water wetter... it will make you run a little cooler... on average about 10 degrees sometimes all the way up to 20, its a pretty neat formula redline has been selling lately... it costs about the same as a gallon jug of coolant... we've been using it at the shop a lot lately... mainly on cars having overheating problems with customers too cheap to have their whole cooling system cleaned out and such.... seems to work