This is almost like talking about politics, But here is my two cents worth.
Synthetic oils are always better, and the best to buy bar none is ROYAL PURPLE just ask any pro race car driver ( NASCAR NHRA AND INDY) the majority of them run it even the ones that advertise for other oils.
They are so confidant in there oil that they have a 1 million dollar reward for anyone that can prove with the simple bearing test that we all have seen on those oil infomercials that another oil is better, And they have had this reward for many years and there has been no one to claim it yet.
I have personaly seen these test done with every type of oil you can think of even with oil additives and nothing has come close.
If you call the company they would probably hook you up with a rep. so you could see for yourself, The rep I talked with also showed us how the other oils did on the test and I was able to see them for myself and I do know that moble 1 is a good oil but it is the worst synthetic as far as pretection out of all, I cant remember what order they came in but I do know that valvoline and the castrol full synthetics were at the top but still was way under the ROYAL PURPLE results.
My dad also works for the public utilities company and thats were I found out about Royal Purple, they use this oil there on there coal crushers and other equipment and my dad has told me many amazing stories about this oil and things it has done, so by using the info of my dad and his experince at work with this oil and talking with the Rep from the company, and then finding out first hand that most race teams use this oil I made my decision I only use Royal Purple and have been very happy with it