Synthetic oils

Unless your particular make engine specifies synthetic motor oil in your vehicle owners manual, synthetic oil won't amount to a hill of beans difference if you keep the oil changed at least what the manufacturer says. PERIOD. You'll have no sludge buildup, no gumups, no nuthin as long as you CHANGE IT. That's the number one most important thing to do. Unless your vehicle requires synthetic from the factory, it's all pretty much marketing hype.