i have been using synthetics since mobil 1 came out around 1977 or so. i have found no problems at all with synthetics, in fact, like someone said here, all measureable tests indicate the superior qualities of synthetics. i do agree that clean quality oil is important. i think its also important to warm an engine before driving . i will continue using synthetics, i do believe they run cleaner and are slipperier. its important to keep our engines as clean as possible as they get older.