Choosing the best, whether synthetic or conventional, engine oil is highly controversial and debated. Motor oil is surrounded with myths and questions. Today we'll look at the answers to these common motor oil questions: What does 5W-30 mean? Why should I change my oil? What is the typical composition of motor oil? Are aftermarket oil additives needed? What does synthetic oil mean? Can you mix synthetic with conventional oil? Can synthetic be used to break in an engine? What causes sludge? Why should I use the viscosity grade that the manufacturer recommends? Check out the video below for the answers to these frequently asked questions. And remember, if you're ever unsure about a topic like this as it applies to your cars, we're only a phone call away