Our pal Jason Fenske at Engineering Explained addresses one of the most commonly-asked questions about car maintenance: should you use synthetic motor oil or conventional motor oil in your car? The safe answer, of course, is to read your car’s owner’s manual and follow the automaker’s directions. However, as Jason explains, there’s more to it than just picking a fancy oil for a car. In this brief film, he takes a look at two Pennzoil motor oils—one formulated specifically for vehicles with high mileage and another billed as a flagship synthetic. At the Canadian Grand Prix this year, Jason had the opportunity to sit down with some of Pennzoil’s engineers to learn just what it is that one of the world’s largest petroleum products manufacturers recommends for every vehicle. He clarifies quickly just what an oil’s viscosity rating means and how that applies to your vehicle, and then he tells us about the differences between conventional and synthetic oils. The video, like all of those in his Engineering Explained series, is easy to follow and informative. It’s definitely worth a watch before you do your next oil change, so you may want to grab a pen and a pad of paper to take some notes!