Ive had bad luck switching from dino to syn in cars with "a few" miles on them. Syn oil acts as a detergent and if you have a car that has been running dino for a while chances are some of the stuff in your dino will be holding some of you gaskets together. add syn, get an umbrella (synthetic oil is much less dense too). If its new and you start with Mobil1 you will virtually see no wear on an engine even after "a few" miles. my .02