People here have brought up some great points. This is a topic that has been widely debated on forums everywhere. I've been fortunate enough to own a decent number of new cars... I've always waited until several thousand miles to switch to synthetic to give the rings a chance to properly seat, and the cylinder walls a chance to wear a bit. Some of my car buddies have switched right away... and honestly, no one has seen issues from doing this that I know of. Shoot... I bought a 2010 Camaro 2SS/RS back in November, and it came filled with Mobile 1 from the factory. Same thing with my dad's porsche. Granted these cars were intended to run synthetic from the factory... but it goes to show that running synthetic in a new motor probably isn't the end of the world.