Are there some conventional motor oils that can actually outperform some synthetic oils? The reason I bring this up is because I once tried a supposedly synthetic oil from a major motor oil manufacturer which ran badly in my car. Some of the so-called synthetic oils could even be questionable that they are even synthetic. I have had conventional motor oils run great in my car. I can also think of a part synthetic oil that I have tried that feels like Mobil 1-I realize that is unscientific but that is what it feels like and sounds like.