Everyone from mechanics, to your uncle that works on cars, has at some point given you advice concerning engine oil. The fact of the matter is that while we are familiar with words like “synthetic” and “oil weight,” many people don’t know exactly what the terminology means, or why common knowledge about oil exists in the form that it does. At Harold's Used Auto Parts Inc in Philadelphia, PA, we keep things clear and simple. The more you know about your vehicle, the better equipped you are to keep it maintained, and we know a thing or two about vehicles. We have compiled a short list of common myths for you, most of which you’ve heard, but maybe never second guessed.