Using the proper oil in your vehicle is one of the most important steps to keeping a good healthy running car. Without proper oil and oil levels your engine could seize up and cost thousands of dollars to repair. So how do you know what oil or what brand oil to use in your car?
Brand is really up to you, Valvoline is a very popular brand and works well in all cars. Its really just comes down to what your prefer, however I do sometimes look to see what the manufacture recommends and what came in the vehicle from the factory. Sometimes mixing oils can cause issues such as sludge buildup.
Synthetic or conventional? I normally go by how new the vehicle is and how many miles it has on it, if its low miles I almost always use synthetic if its a high mileage car and never has ran synthetic then I will stick with conventional. Its possible that switching to synthetic after years of running conventional could cause some issues.